Mental Illness vs. Suicide

Do countries with more mental illness have more suicides?

At first glance, it seems as though the answer must be "yes". Although not all suicides are related to mental illness, unsurprisingly people with mental illness do have a much higher suicide rate than people without. So, all other things being equal, the rate of mental illness in a country should correlate with the suicide rate. Of course, all other things are not equal, and other factors might come into play such as the quality of mental health services. But it still seems as though there should be a correlation, albeit not a perfect one, between mental illness and suicide.

I decided to see whether or not there is such a correlation. The World Health Organization (WHO) provides the relevant data here. There have only ever been three studies attempting to measure rates of common mental illnesses internationally (1,2,3), and all three were run by the WHO. The WHO also collates national suicide rates (here) for most countries, although a few are missing. No-one seems to have published anything looking for a correlation between these two sets of numbers of before, or if they did, I've failed to find it.

So what's the story? Take a look -


In short, there's no correlation. The Pearson correlation (unweighted) r = 0.102, which is extremely low. As you can see, both mental illness and suicide rates vary greatly around the world, but there's no relationship. Japan has the second highest suicide rate, but one of the lowest rates of mental illnesses. The USA has the highest rate of mental illness, but a fairly low suicide rate. Brazil has the second highest level of mental illness but the second lowest occurrence of suicide.

*

Some technical notes: Two of the three surveys, the ICPE (2000) and the WMHS (2004), sampled the whole population of each country. The other one, which was also the earliest, the PPGHC (1993), surveyed people attending family doctors. Because this is a slightly different approach, I used the ICPE and the WMHS for the plot above, although the results from the PPGHC are very similar (see below).

The ICPE sampled 7 countries and the WMHS sampled 14, but 4 countries were included in both surveys, so there's a total of 17 countries. I've used the mean of the ICPE and the WMHS for those 4 countries where we have data from both, for the rest I've used whichever is available. For the suicide rates, the WHO gives data for various different years, so I've used 2002, or the nearest available year, since this is between 2000 and 2004. For two countries, Lebanon and Nigeria, the WHO do not report suicide rates. For China, rates of mental illness are given in both Beijing and Shanghai.

The studies used structured diagnostic interviews to try to measure the percentage of people suffering from mental illness in the 12 months before the interview. As I've said previously, this -

attempts to study a random sample of the population of a certain country. In order to establish whether each person is mentally ill or not, they use structured diagnostic interviews. These consists in asking the subject a fixed ("structured") series of questions, and declaring them to have a certain mental disorder if they answer "Yes" to a given number of them.

In this case the structured question interview was called the CIDI and it used DSM-IV criteria. You can check it out here. Example question:

You mentioned having periods that lasted several days or longer when you felt sad, empty, or depressed most of the day. During episodes of this sort, did you ever feel discouraged about how things were going in your life? (YES, NO, DON’T KNOW, REFUSED)

*

The rates from the population surveys (ICPE & WMHS) don't correlate with suicide but they do correlate with the rates from the PPGHC survey of people attending family doctors. The association here is very strong, with a correlation r = 0.693. The only outlier is the US. This is despite the fact that a decade elapsed between the first survey (1993) and the other two (2000, 2004).

This is important because it shows that the mental illness surveys are measuring something about these countries, something which is stable over time. They're not just producing random junk results. But whatever they're measuring, it's not related to suicide.

*

What does this mean? You leave a comment and tell me. But here's my take. I've often expressed skepticism of population surveys and their (very high) estimates of mental illness, and of the dubious political conclusions certain people have tried to draw from them, but even so, I was surprised to find no correlation at all with suicide. I'd say that any meaningful measure of mental illness should correlate with suicide. These surveys, using the CIDI, don't, so to me they're not meaningful.

One thing to bear in mind about these numbers is that they deal with "common" mental illnesses like depression, substance abuse and anxiety. They leave out the most severe disorders such as schizophrenia. Also, people in psychiatric hospitals, in prison, and the homeless, will not have been included in the studies because they sample "households". That could be why there's no association with suicide, but if so then these surveys are missing a very important aspect of mental health.

The surveys do seem to measure something, but I don't think it has much to do with mental illness. This is just a guess but I suspect they're measuring willingness to talk about your emotional life to strangers. At least stereotypically, the Chinese and the Japanese are known as more reserved in this regard than Brazilians and Americans. So it's no surprise that when you ask people a load of personal questions, the "rates of mental illness" seem to be lower in Japan than in America. This doesn't mean Americans are really more ill, just more open.

I've been talking about surveys looking at differences between countries, but if these are flawed, then so are surveys looking at just one country. For example, many studies have looked at mental illness in the USA using similar methods to these. But can we trust these methods bearing in mind that if you ask the same questions in, say, Belgium you get less than half the estimated rate despite it having double the number of suicides? Taken to its logical conclusion, maybe we know little about the prevalence of "common mental illness" anywhere.

Sartorius N, Ustün TB, Costa e Silva JA, Goldberg D, Lecrubier Y, Ormel J, Von Korff M, & Wittchen HU (1993). An international study of psychological problems in primary care. Preliminary report from the World Health Organization Collaborative Project on 'Psychological Problems in General Health Care'. Archives of general psychiatry, 50 (10), 819-24 PMID: 8215805

WHO (2000). Cross-national comparisons of the prevalences and correlates of mental disorders. WHO International Consortium in Psychiatric Epidemiology. Bulletin of the World Health Organization, 78 (4), 413-26 PMID: 10885160

Demyttenaere K, & et Al (2004). Prevalence, severity, and unmet need for treatment of mental disorders in the World Health Organization World Mental Health Surveys. JAMA, 291 (21), 2581-90 PMID: 15173149

Mental Illness vs. Suicide

Do countries with more mental illness have more suicides?

At first glance, it seems as though the answer must be "yes". Although not all suicides are related to mental illness, unsurprisingly people with mental illness do have a much higher suicide rate than people without. So, all other things being equal, the rate of mental illness in a country should correlate with the suicide rate. Of course, all other things are not equal, and other factors might come into play such as the quality of mental health services. But it still seems as though there should be a correlation, albeit not a perfect one, between mental illness and suicide.

I decided to see whether or not there is such a correlation. The World Health Organization (WHO) provides the relevant data here. There have only ever been three studies attempting to measure rates of common mental illnesses internationally (1,2,3), and all three were run by the WHO. The WHO also collates national suicide rates (here) for most countries, although a few are missing. No-one seems to have published anything looking for a correlation between these two sets of numbers of before, or if they did, I've failed to find it.

So what's the story? Take a look -


In short, there's no correlation. The Pearson correlation (unweighted) r = 0.102, which is extremely low. As you can see, both mental illness and suicide rates vary greatly around the world, but there's no relationship. Japan has the second highest suicide rate, but one of the lowest rates of mental illnesses. The USA has the highest rate of mental illness, but a fairly low suicide rate. Brazil has the second highest level of mental illness but the second lowest occurrence of suicide.

*

Some technical notes: Two of the three surveys, the ICPE (2000) and the WMHS (2004), sampled the whole population of each country. The other one, which was also the earliest, the PPGHC (1993), surveyed people attending family doctors. Because this is a slightly different approach, I used the ICPE and the WMHS for the plot above, although the results from the PPGHC are very similar (see below).

The ICPE sampled 7 countries and the WMHS sampled 14, but 4 countries were included in both surveys, so there's a total of 17 countries. I've used the mean of the ICPE and the WMHS for those 4 countries where we have data from both, for the rest I've used whichever is available. For the suicide rates, the WHO gives data for various different years, so I've used 2002, or the nearest available year, since this is between 2000 and 2004. For two countries, Lebanon and Nigeria, the WHO do not report suicide rates. For China, rates of mental illness are given in both Beijing and Shanghai.

The studies used structured diagnostic interviews to try to measure the percentage of people suffering from mental illness in the 12 months before the interview. As I've said previously, this -

attempts to study a random sample of the population of a certain country. In order to establish whether each person is mentally ill or not, they use structured diagnostic interviews. These consists in asking the subject a fixed ("structured") series of questions, and declaring them to have a certain mental disorder if they answer "Yes" to a given number of them.

In this case the structured question interview was called the CIDI and it used DSM-IV criteria. You can check it out here. Example question:

You mentioned having periods that lasted several days or longer when you felt sad, empty, or depressed most of the day. During episodes of this sort, did you ever feel discouraged about how things were going in your life? (YES, NO, DON’T KNOW, REFUSED)

*

The rates from the population surveys (ICPE & WMHS) don't correlate with suicide but they do correlate with the rates from the PPGHC survey of people attending family doctors. The association here is very strong, with a correlation r = 0.693. The only outlier is the US. This is despite the fact that a decade elapsed between the first survey (1993) and the other two (2000, 2004).

This is important because it shows that the mental illness surveys are measuring something about these countries, something which is stable over time. They're not just producing random junk results. But whatever they're measuring, it's not related to suicide.

*

What does this mean? You leave a comment and tell me. But here's my take. I've often expressed skepticism of population surveys and their (very high) estimates of mental illness, and of the dubious political conclusions certain people have tried to draw from them, but even so, I was surprised to find no correlation at all with suicide. I'd say that any meaningful measure of mental illness should correlate with suicide. These surveys, using the CIDI, don't, so to me they're not meaningful.

One thing to bear in mind about these numbers is that they deal with "common" mental illnesses like depression, substance abuse and anxiety. They leave out the most severe disorders such as schizophrenia. Also, people in psychiatric hospitals, in prison, and the homeless, will not have been included in the studies because they sample "households". That could be why there's no association with suicide, but if so then these surveys are missing a very important aspect of mental health.

The surveys do seem to measure something, but I don't think it has much to do with mental illness. This is just a guess but I suspect they're measuring willingness to talk about your emotional life to strangers. At least stereotypically, the Chinese and the Japanese are known as more reserved in this regard than Brazilians and Americans. So it's no surprise that when you ask people a load of personal questions, the "rates of mental illness" seem to be lower in Japan than in America. This doesn't mean Americans are really more ill, just more open.

I've been talking about surveys looking at differences between countries, but if these are flawed, then so are surveys looking at just one country. For example, many studies have looked at mental illness in the USA using similar methods to these. But can we trust these methods bearing in mind that if you ask the same questions in, say, Belgium you get less than half the estimated rate despite it having double the number of suicides? Taken to its logical conclusion, maybe we know little about the prevalence of "common mental illness" anywhere.

Sartorius N, Ustün TB, Costa e Silva JA, Goldberg D, Lecrubier Y, Ormel J, Von Korff M, & Wittchen HU (1993). An international study of psychological problems in primary care. Preliminary report from the World Health Organization Collaborative Project on 'Psychological Problems in General Health Care'. Archives of general psychiatry, 50 (10), 819-24 PMID: 8215805

WHO (2000). Cross-national comparisons of the prevalences and correlates of mental disorders. WHO International Consortium in Psychiatric Epidemiology. Bulletin of the World Health Organization, 78 (4), 413-26 PMID: 10885160

Demyttenaere K, & et Al (2004). Prevalence, severity, and unmet need for treatment of mental disorders in the World Health Organization World Mental Health Surveys. JAMA, 291 (21), 2581-90 PMID: 15173149

On Sexed-Up Statistics

In yesterday's Guardian, Nick Davies, author of seemingly every British blogger's favourite book, Flat Earth News, delivered a pair of remarkable articles that confirmed him as one of the country's most important journalists.

In the first, Davies reported that a recent nationwide police initiative, Operation Pentameter, did not convict anyone of the crime of forcing women into prostitution after illegally trafficking them into the country.

This is rather surprising because, as he explains in a companion comment piece, forced sex trafficking has been widely reported as rife in Britain. The government has been telling Parliament and the nation that there are no less than 25,000 victims across the country. Anti-prostitution groups and charities agreed. Davies goes on to describe how this startling statistic was constructed through a process of exaggeration, misunderstanding, and plain invention.

In 1998, two academics identified a total of 71 trafficked women in the UK, and this did not refer specifically to forced or coerced trafficking. They suggested that the true figure could be anywhere between 142 and 1,420, but admitted that this was speculation, based on the assumption that for every confirmed case, there might be 2 to 20 in reality. A Christian charity quoted this as "an estimated 1,420 women", and others quoted them. The snowball had begun.

A second study estimated 4,000 victims of trafficking, but the researchers noted that this figure was "subject to a very large margin of error", "should be treated with great caution" and "should be regarded as an upper bound", as it was based on many assumptions. Heedless, another major charity quoted this as "4,000 trafficked women ... this figure is believed to be a massive underestimation of the problem". The government started repeating 4,000 as a fact.

Not to be outdone, a tabloid headline then reported no less than 25,000 sex slaves on the streets of Britain! Politicians started quoting this as a fact, although the newspaper provided no evidence for this figure at all. Asked why they believed it, a government minister said he used to work for the tabloid in question, and he trusted them to be accurate.

*

I have no idea how common forced sex trafficking is. I'd imagine it's not an easy thing to detect, let alone prove in court, so it could be going on behind closed doors and never make it into the statistics. It does happen, and obviously, every case is one too many.

But what certainly is true is that statistics have been greatly exaggerated, and then repeated, by the government and by various campaigning organizations. For more informed commentary on the issue by workers in the field, see Dr Petra Boynton's remarks here and the ongoing discussion here featuring Boynton and Belinda Brooks-Gordon.

Politician Dennis McShane MP "responded" to the criticisms of the 25,000 figure in an almost unwatchable TV interview and unconvincing article in which, amongst other things, he claims that 25,000 came from Amnesty International statistics. This is an outright lie. In fact, the tabloid did quote someone from Amnesty who commented on trafficking in general, but they didn't mention about numbers at all.

*

Attentive Neuroskeptic readers may well be experiencing a sense of déjà vu at this point. I have often written about the statistic - ubiquitous in Britain and elsewhere - that "1 in 4 people suffer mental illness". That number is made up, rather like the inflated statistics on forced sex trafficking.

Why are such statistics made up, and why are the made-up numbers usually shockingly high ones? It's no coincidence. This is what happens when the only people with an interest in talking about a statistic also have an interest in making it seem as high as possible. This is not to say that anyone deliberately fiddles the numbers, but rather, people naturally focus on the ones that suit them best.

In the case of mental illness, those who research mental illness know that their funding depends on the idea that it's a widespread problem. The more common people think it is, the more important studying it seems. Meanwhile, charities representing the interests of the mentally ill like high statistics because they make mental illness seem more "normal", thus destigmatizing it. It can't hurt their donation rates either.

With sex slavery, the inflated statistics were produced and repeated by organisations opposed to prostitution on moral grounds (including Christian charities and feminist groups), and by the government. The government's interest in the matter seems to be that they are currently trying to pass a law further restricting prostitution and the sex industry. The 25,000 supposed sex slaves must have helped convince Parliament about the importance of this move...

There must be many other examples of inflated statistics out there. It's inevitable, because in order to be taken seriously and to attract money, media attention and political support, campaigning organisations need to make their cause sound important. We can hardly blame charities for doing this, and as for politicians, we know not to trust them about anything. To expect an activist group or a political party to deal with evidence in a neutral and objective way is just naive.

What we'll always need, therefore, is people to scrutinize claims about social problems to keep the campaigners and the politicians honest. This is, or should be, the job of the media, but as Davies points out, the British media completely failed to do this for years. There will always be sexed-up statistics. What we need is more journalists like Davies to sex them back down again.

[BPSDB]

On Sexed-Up Statistics

In yesterday's Guardian, Nick Davies, author of seemingly every British blogger's favourite book, Flat Earth News, delivered a pair of remarkable articles that confirmed him as one of the country's most important journalists.

In the first, Davies reported that a recent nationwide police initiative, Operation Pentameter, did not convict anyone of the crime of forcing women into prostitution after illegally trafficking them into the country.

This is rather surprising because, as he explains in a companion comment piece, forced sex trafficking has been widely reported as rife in Britain. The government has been telling Parliament and the nation that there are no less than 25,000 victims across the country. Anti-prostitution groups and charities agreed. Davies goes on to describe how this startling statistic was constructed through a process of exaggeration, misunderstanding, and plain invention.

In 1998, two academics identified a total of 71 trafficked women in the UK, and this did not refer specifically to forced or coerced trafficking. They suggested that the true figure could be anywhere between 142 and 1,420, but admitted that this was speculation, based on the assumption that for every confirmed case, there might be 2 to 20 in reality. A Christian charity quoted this as "an estimated 1,420 women", and others quoted them. The snowball had begun.

A second study estimated 4,000 victims of trafficking, but the researchers noted that this figure was "subject to a very large margin of error", "should be treated with great caution" and "should be regarded as an upper bound", as it was based on many assumptions. Heedless, another major charity quoted this as "4,000 trafficked women ... this figure is believed to be a massive underestimation of the problem". The government started repeating 4,000 as a fact.

Not to be outdone, a tabloid headline then reported no less than 25,000 sex slaves on the streets of Britain! Politicians started quoting this as a fact, although the newspaper provided no evidence for this figure at all. Asked why they believed it, a government minister said he used to work for the tabloid in question, and he trusted them to be accurate.

*

I have no idea how common forced sex trafficking is. I'd imagine it's not an easy thing to detect, let alone prove in court, so it could be going on behind closed doors and never make it into the statistics. It does happen, and obviously, every case is one too many.

But what certainly is true is that statistics have been greatly exaggerated, and then repeated, by the government and by various campaigning organizations. For more informed commentary on the issue by workers in the field, see Dr Petra Boynton's remarks here and the ongoing discussion here featuring Boynton and Belinda Brooks-Gordon.

Politician Dennis McShane MP "responded" to the criticisms of the 25,000 figure in an almost unwatchable TV interview and unconvincing article in which, amongst other things, he claims that 25,000 came from Amnesty International statistics. This is an outright lie. In fact, the tabloid did quote someone from Amnesty who commented on trafficking in general, but they didn't mention about numbers at all.

*

Attentive Neuroskeptic readers may well be experiencing a sense of déjà vu at this point. I have often written about the statistic - ubiquitous in Britain and elsewhere - that "1 in 4 people suffer mental illness". That number is made up, rather like the inflated statistics on forced sex trafficking.

Why are such statistics made up, and why are the made-up numbers usually shockingly high ones? It's no coincidence. This is what happens when the only people with an interest in talking about a statistic also have an interest in making it seem as high as possible. This is not to say that anyone deliberately fiddles the numbers, but rather, people naturally focus on the ones that suit them best.

In the case of mental illness, those who research mental illness know that their funding depends on the idea that it's a widespread problem. The more common people think it is, the more important studying it seems. Meanwhile, charities representing the interests of the mentally ill like high statistics because they make mental illness seem more "normal", thus destigmatizing it. It can't hurt their donation rates either.

With sex slavery, the inflated statistics were produced and repeated by organisations opposed to prostitution on moral grounds (including Christian charities and feminist groups), and by the government. The government's interest in the matter seems to be that they are currently trying to pass a law further restricting prostitution and the sex industry. The 25,000 supposed sex slaves must have helped convince Parliament about the importance of this move...

There must be many other examples of inflated statistics out there. It's inevitable, because in order to be taken seriously and to attract money, media attention and political support, campaigning organisations need to make their cause sound important. We can hardly blame charities for doing this, and as for politicians, we know not to trust them about anything. To expect an activist group or a political party to deal with evidence in a neutral and objective way is just naive.

What we'll always need, therefore, is people to scrutinize claims about social problems to keep the campaigners and the politicians honest. This is, or should be, the job of the media, but as Davies points out, the British media completely failed to do this for years. There will always be sexed-up statistics. What we need is more journalists like Davies to sex them back down again.

[BPSDB]

Antidepressant Sales Rise as Depression Falls

Antidepressant sales are rising in most Western countries, and they have been for at least a decade. Recently, we learned that the proportion of Americans taking antidepressants in any given year nearly doubled from 1996 to 2005.

The situation has been thought to be similar in the UK. But a hot-off-the-press paper in the British Medical Journal reveals some surprising facts about the issue: Explaining the rise in antidepressant prescribing.

The authors examined medical records from 1.7 million British patients in primary care (General Practice, i.e. family doctors.) They found that antidepressant sales rose strongly between 1993 and 2005, not because more people are taking these drugs, but entirely because of an increase in the duration of treatment amongst the antidepressant users. It's not that more people are taking them, it's that people are taking them for longer.

In fact, the number of people being diagnosed with depression and prescribed antidepressants has actually fallen over time. The rate of diagnosed depression remained steady from 1993 to about 2001, and then fell markedly, by about a third, up to 2005. This trend was seen in both men and women, but there were age differences. In 18-30 year olds, there was a gradual increase in diagnoses before the decrease. (Note that these graphs show the number of people getting their first ever diagnosis of depression in each year.)
The likelihood of being given antidepressants for a diagnosis of depression stayed roughly constant, at about 75-80% across the years. However, the average duration of treatment increased over time -

The change doesn't look like much, but remember that even a small change in the number of long-term users translates into a large effect on the total number of sales, because each long-term user takes a lot of pills. The authors conclude

Antidepressant prescribing nearly doubled during the study period—the average number of prescriptions issued per patient increased from 2.8 in 1993 to 5.6 in 2004. ... the rise in antidepressant prescribing is mainly explained by small changes in the proportion of patients receiving long term treatment.

Wow. I didn't see that coming, I'll admit. A lot of people, myself included, had assumed that rising antidepressant use was caused by people becoming more willing to seek treatment for depression. Or maybe that doctors were becoming more eager to prescribe drugs. Others believed that rates of clinical depression were rising.

There's no evidence for either of these theories in this British data-set. The recent fall in clinical depression diagnoses, following an increase in young people over the course of the 1990s, is especially surprising. This conflicts with the only British population survey of mental health, the APMS. The APMS found that rates of depression and mixed anxiety/depression increased between 1993 and 2000 in most age groups but least of all in the young, and little change 2000 to 2007. I trust this new data more, because population surveys almost certainly overestimate mental illness.

How does this result compare to elsewhere? In the USA, the average number of antidepressant prescriptions per patient per year rose from "5.60 in 1996 to 6.93 in 2005" according to a recent estimate. In this study yearly "prescriptions issued per patient increased from 2.8 in 1993 to 5.6 in 2004." So there's a major trans-Atlantic difference. In Britain, the length of use increased greatly, while in the US it only rose slightly, but from a higher baseline.

Finally, why has this happened? We can only speculate. Maybe doctors have become more keen on long-term treatment to prevent depressive relapse. Or maybe users have become more willing to take antidepressants long-term. Modern drugs generally have milder side effects than older ones, so this makes sense, although some people would say that this is just further proof that modern antidepressants are "addictive"...

Moore M, Yuen HM, Dunn N, Mullee MA, Maskell J, & Kendrick T (2009). Explaining the rise in antidepressant prescribing: a descriptive study using the general practice research database. BMJ (Clinical research ed.), 339 PMID: 19833707

Antidepressant Sales Rise as Depression Falls

Antidepressant sales are rising in most Western countries, and they have been for at least a decade. Recently, we learned that the proportion of Americans taking antidepressants in any given year nearly doubled from 1996 to 2005.

The situation has been thought to be similar in the UK. But a hot-off-the-press paper in the British Medical Journal reveals some surprising facts about the issue: Explaining the rise in antidepressant prescribing.

The authors examined medical records from 1.7 million British patients in primary care (General Practice, i.e. family doctors.) They found that antidepressant sales rose strongly between 1993 and 2005, not because more people are taking these drugs, but entirely because of an increase in the duration of treatment amongst the antidepressant users. It's not that more people are taking them, it's that people are taking them for longer.

In fact, the number of people being diagnosed with depression and prescribed antidepressants has actually fallen over time. The rate of diagnosed depression remained steady from 1993 to about 2001, and then fell markedly, by about a third, up to 2005. This trend was seen in both men and women, but there were age differences. In 18-30 year olds, there was a gradual increase in diagnoses before the decrease. (Note that these graphs show the number of people getting their first ever diagnosis of depression in each year.)
The likelihood of being given antidepressants for a diagnosis of depression stayed roughly constant, at about 75-80% across the years. However, the average duration of treatment increased over time -

The change doesn't look like much, but remember that even a small change in the number of long-term users translates into a large effect on the total number of sales, because each long-term user takes a lot of pills. The authors conclude

Antidepressant prescribing nearly doubled during the study period—the average number of prescriptions issued per patient increased from 2.8 in 1993 to 5.6 in 2004. ... the rise in antidepressant prescribing is mainly explained by small changes in the proportion of patients receiving long term treatment.

Wow. I didn't see that coming, I'll admit. A lot of people, myself included, had assumed that rising antidepressant use was caused by people becoming more willing to seek treatment for depression. Or maybe that doctors were becoming more eager to prescribe drugs. Others believed that rates of clinical depression were rising.

There's no evidence for either of these theories in this British data-set. The recent fall in clinical depression diagnoses, following an increase in young people over the course of the 1990s, is especially surprising. This conflicts with the only British population survey of mental health, the APMS. The APMS found that rates of depression and mixed anxiety/depression increased between 1993 and 2000 in most age groups but least of all in the young, and little change 2000 to 2007. I trust this new data more, because population surveys almost certainly overestimate mental illness.

How does this result compare to elsewhere? In the USA, the average number of antidepressant prescriptions per patient per year rose from "5.60 in 1996 to 6.93 in 2005" according to a recent estimate. In this study yearly "prescriptions issued per patient increased from 2.8 in 1993 to 5.6 in 2004." So there's a major trans-Atlantic difference. In Britain, the length of use increased greatly, while in the US it only rose slightly, but from a higher baseline.

Finally, why has this happened? We can only speculate. Maybe doctors have become more keen on long-term treatment to prevent depressive relapse. Or maybe users have become more willing to take antidepressants long-term. Modern drugs generally have milder side effects than older ones, so this makes sense, although some people would say that this is just further proof that modern antidepressants are "addictive"...

Moore M, Yuen HM, Dunn N, Mullee MA, Maskell J, & Kendrick T (2009). Explaining the rise in antidepressant prescribing: a descriptive study using the general practice research database. BMJ (Clinical research ed.), 339 PMID: 19833707

Most People Experience "Mental Illness" By Age 32

Mental illness: how common is it? A popular answer is one in four - 25% of people will experience it at least once in their lives. In fact, most published research suggests that the lifetime rate is higher, around 30-50%, in Western nations.

That's a lot. But even this may be a serious underestimate, according to a new paper, How common are common mental disorders? The study compared the proportion of people reporting mental illness under two different research methods: retrospective and prospective.

Retrospective means asking people to think back and remember whether they ever have felt a certain way. A prospective study, however, recruits people and then follows them up for a certain length of time, asking them how they feel at regular intervals.

The obvious advantage of prospective studies is that there is less chance of forgetting. In a retrospective study, people are required to remember how they were feeling years, or even decades, ago. Human memory just isn't that good. A prospective study requires some remembering, as people are generally asked to report how they've felt over the last year, but this is clearly less problematic.

The prospective study in question here included 1,000 people from Dunedin, New Zealand. The volunteers were followed from birth to age 32, and were interviewed at ages 18, 21, 26 and 32. The results were compared to three large retrospective lifetime studies, two American and one from NZ. (1,2,3).

50% of the Dunedin prospective cohort reported at least one "anxiety disorder", 41% reported "depression", 32% confessed to "alcohol dependence" and 18% to "cannabis dependence". (Those were the only conditions studied.) For some reason, we're not told how much overlap there was, but even assuming there was a lot, well over half of all the cohort will have experienced at least one disorder. If the overlap was low, it could be almost all of them. And remember, this is just up to age 32. And there still may have been some forgetting...

Compared to the retrospective studies, these rates are all about twice as high. What does this mean for psychiatry?

First, it suggests that retrospective studies, which are by far the most common, are flawed. People just tend to forget a lot of "mental illness" when asked to remember across the lifetime. More evidence for this comes from the fact that the ratio of past-year to lifetime reported disorders was 38% in the prospective study compared to about 60% in the retrospective ones.

But there's a more profound implication. A growing number of critics have argued that the very high reported lifetime rates of mental disorders mean that the way most psychiatrists diagnose mental illness is flawed. The "Bible" of modern psychiatric diagnosis is the Diagnostic and Statistical Manual (DSM) of Mental Disorders of the American Psychiatric Association. DSM diagnostic criteria were used in the studies in question here.

These results suggest that DSM diagnoses are even more common than previously believed, which only strengthens the critics' case. According to DSM criteria, at least 40% of people experience "Major Depressive Disorder" by age 32.

In which case, what is it? A fairly usual part of human life. So, calling it a disease and treating it with drugs or therapy seems rather presumptuous. Especially since so many people who "suffer" from it manage to not only get over it, but actually forget it ever happened. (Of course, this shouldn't be taken to mean that real, serious clinical depression doesn't exist.)

The authors conclude - listen carefully -

This article is uninformative (and agnostic) about the validity of diagnoses as defined by DSM-IV ... [rather], objections voiced to surveys’ higher than expected lifetime prevalence of disorder are objections to prevalence that is only half what it could be in reality...

Researchers might begin to ask why so many people experience a DSM-defined disorder at least once during their lifetimes, and what this prevalence means for etiological theory, the construct validity of the DSM approach to defining disorder, service-delivery policy, the economic burden of disease, and public perceptions of the stigma of mental disorder.

That hammering sound you hear is another nail sealing the coffin of DSM's credibility. If many* DSM "disorders" are simply descriptions of normal parts of human life, we need to take a long, hard look at those "disorders", and rethink whether they need to labelled and treated as medical problems.

The newest edition of DSM, DSM-5, is currently in development. This would seem like a great opportunity to do just that. Unfortunately, the development process is rapidly degenerating into farce. If DSM-5 does not address the issues raised here, many people will be tempted to give up on DSM entirely.

* Not all: the great majority of people will never meet criteria for schizophrenia or bipolar disorder, for example.

Moffitt, T., Caspi, A., Taylor, A., Kokaua, J., Milne, B., Polanczyk, G., & Poulton, R. (2009). How common are common mental disorders? Evidence that lifetime prevalence rates are doubled by prospective versus retrospective ascertainment Psychological Medicine DOI: 10.1017/S0033291709991036

Most People Experience "Mental Illness" By Age 32

Mental illness: how common is it? A popular answer is one in four - 25% of people will experience it at least once in their lives. In fact, most published research suggests that the lifetime rate is higher, around 30-50%, in Western nations.

That's a lot. But even this may be a serious underestimate, according to a new paper, How common are common mental disorders? The study compared the proportion of people reporting mental illness under two different research methods: retrospective and prospective.

Retrospective means asking people to think back and remember whether they ever have felt a certain way. A prospective study, however, recruits people and then follows them up for a certain length of time, asking them how they feel at regular intervals.

The obvious advantage of prospective studies is that there is less chance of forgetting. In a retrospective study, people are required to remember how they were feeling years, or even decades, ago. Human memory just isn't that good. A prospective study requires some remembering, as people are generally asked to report how they've felt over the last year, but this is clearly less problematic.

The prospective study in question here included 1,000 people from Dunedin, New Zealand. The volunteers were followed from birth to age 32, and were interviewed at ages 18, 21, 26 and 32. The results were compared to three large retrospective lifetime studies, two American and one from NZ. (1,2,3).

50% of the Dunedin prospective cohort reported at least one "anxiety disorder", 41% reported "depression", 32% confessed to "alcohol dependence" and 18% to "cannabis dependence". (Those were the only conditions studied.) For some reason, we're not told how much overlap there was, but even assuming there was a lot, well over half of all the cohort will have experienced at least one disorder. If the overlap was low, it could be almost all of them. And remember, this is just up to age 32. And there still may have been some forgetting...

Compared to the retrospective studies, these rates are all about twice as high. What does this mean for psychiatry?

First, it suggests that retrospective studies, which are by far the most common, are flawed. People just tend to forget a lot of "mental illness" when asked to remember across the lifetime. More evidence for this comes from the fact that the ratio of past-year to lifetime reported disorders was 38% in the prospective study compared to about 60% in the retrospective ones.

But there's a more profound implication. A growing number of critics have argued that the very high reported lifetime rates of mental disorders mean that the way most psychiatrists diagnose mental illness is flawed. The "Bible" of modern psychiatric diagnosis is the Diagnostic and Statistical Manual (DSM) of Mental Disorders of the American Psychiatric Association. DSM diagnostic criteria were used in the studies in question here.

These results suggest that DSM diagnoses are even more common than previously believed, which only strengthens the critics' case. According to DSM criteria, at least 40% of people experience "Major Depressive Disorder" by age 32.

In which case, what is it? A fairly usual part of human life. So, calling it a disease and treating it with drugs or therapy seems rather presumptuous. Especially since so many people who "suffer" from it manage to not only get over it, but actually forget it ever happened. (Of course, this shouldn't be taken to mean that real, serious clinical depression doesn't exist.)

The authors conclude - listen carefully -

This article is uninformative (and agnostic) about the validity of diagnoses as defined by DSM-IV ... [rather], objections voiced to surveys’ higher than expected lifetime prevalence of disorder are objections to prevalence that is only half what it could be in reality...

Researchers might begin to ask why so many people experience a DSM-defined disorder at least once during their lifetimes, and what this prevalence means for etiological theory, the construct validity of the DSM approach to defining disorder, service-delivery policy, the economic burden of disease, and public perceptions of the stigma of mental disorder.

That hammering sound you hear is another nail sealing the coffin of DSM's credibility. If many* DSM "disorders" are simply descriptions of normal parts of human life, we need to take a long, hard look at those "disorders", and rethink whether they need to labelled and treated as medical problems.

The newest edition of DSM, DSM-5, is currently in development. This would seem like a great opportunity to do just that. Unfortunately, the development process is rapidly degenerating into farce. If DSM-5 does not address the issues raised here, many people will be tempted to give up on DSM entirely.

* Not all: the great majority of people will never meet criteria for schizophrenia or bipolar disorder, for example.

Moffitt, T., Caspi, A., Taylor, A., Kokaua, J., Milne, B., Polanczyk, G., & Poulton, R. (2009). How common are common mental disorders? Evidence that lifetime prevalence rates are doubled by prospective versus retrospective ascertainment Psychological Medicine DOI: 10.1017/S0033291709991036

U.S. Antidepressant Use Doubled in A Decade

The proportion of Americans using antidepressants in a given year nearly doubled from 5.8% in 1996 to 10.1% in 2005, according to a paper just published: National Patterns in Antidepressant
Medication Treatment, by Mark Olfson and Steven Marcus.

That means about 15 million more Americans were medicated in '05 than a decade previously. A huge increase in anyone's book. But the doubling in antidepressant use is not the only interesting result in this paper. In no particular order, here are some other fun facts -

• Women are twice as likely to use antidepressants as men (female 13.4% vs male 6.7% in 2005); the ratio was the same in 1996. Studies consistently find that Western women are about twice as likely to report suffering from depression and anxiety disorders as men are. But these kinds of studies rely on self-report so this could merely mean that women are more willing to talk about their problems. This data suggests that they also seek treatment about twice as often.
  
• The peak age bracket for antidepressants is 50-64, with 15.5% yearly use. This is more than double the rate in the 18-34 bracket. This surprised me, maybe because of the influence of books like Prozac Nation (tagline - "Young and Depressed in America"). So, it looks like the increasing use of antidepressants is not because younger people, having grown up in the "Prozac Era", are more accepting of them.
  
• Antidepressants are a white thing - 12.0% of whites take them vs. about 5% of blacks and Hispanics. But it would be interesting to see a regional breakdown here. Are blue-state or red-state whites more likely to be medicated?
• Family income was not correlated with antidepressant use, but the unemployed were twice as likely to use antidepressants: 22% in '05. This might be because unemployment is bad for your mental health, or because mental illness is bad for your employment prospects. Or both.
  
• One of the questions in the survey asked people to rate their own mental health. Over 90% of Americans said it as "good", "very good" or "excellent" - including 80% of antidepressants users. This really surprised me, and suggests that these drugs are being prescribed to people who are not, overall, very unwell.
  
• The % of antidepressant users also using an antipsychotic drug rose from 5.5% to 8.9% in 2005. Given that the number of users also doubled, this means the number of Americans using an antipsychotic as well as an antidepressant increased by a factor of more than 3. This is worrying since antipsychotics are generally the worst psychiatric drugs in terms of side effects. While there is evidence that some of the newer antipsychotics can be of use in depression as an add-on to antidepressants, this is controversial and it's not clear that they're any better than the older alternatives, such as lithium.
  

Overall, this report verifies that antidepressant use has risen dramatically over the past several years. This is hardly news, but the magnitude of the increase is still startling.

What makes it especially interesting is that nothing much happened between 1996 and 2005 in terms of new antidepressants. A couple of new SSRIs, such as citalopram, were approved for sale in the US. But these drugs are very similar to Prozac (fluoxetine) which has been around since '87. Remeron (mirtazapine) hit the market in '96, but it's never been nearly as popular as the SSRIs.

So the change was a change in behaviour, a cultural or social phenomenon. For some reason, America decided to take more antidepressants. Books could be written on why this happened, and I hope they will be, because it's an important topic. But here's my personal take: the main reason why people are taking more antidepressants is that the popular concept of "depression" has become more broad. People have become more willing to label their experiences as "depression" and seek medical treatment. The notion that mental illness is extremely common - the one in four meme - is one aspect of this.

Finally, the inevitable caveats. The data here come from the Medical Expenditure Panel Surveys (MEPS) which were household surveys of "national probability samples of the US civilian noninstitutionalized population". This means that military personnel, the homeless, prisoners, and (presumably) illegal immigrants weren't included. And not everyone agreed to take part; the response rate was 70% in '96 but dropped to 60% in '05. On the other hand, the samples were extremely large (28,000 in 2005).

Olfson M, & Marcus SC (2009). National patterns in antidepressant medication treatment. Archives of general psychiatry, 66 (8), 848-56 PMID: 19652124

U.S. Antidepressant Use Doubled in A Decade

The proportion of Americans using antidepressants in a given year nearly doubled from 5.8% in 1996 to 10.1% in 2005, according to a paper just published: National Patterns in Antidepressant
Medication Treatment, by Mark Olfson and Steven Marcus.

That means about 15 million more Americans were medicated in '05 than a decade previously. A huge increase in anyone's book. But the doubling in antidepressant use is not the only interesting result in this paper. In no particular order, here are some other fun facts -

• Women are twice as likely to use antidepressants as men (female 13.4% vs male 6.7% in 2005); the ratio was the same in 1996. Studies consistently find that Western women are about twice as likely to report suffering from depression and anxiety disorders as men are. But these kinds of studies rely on self-report so this could merely mean that women are more willing to talk about their problems. This data suggests that they also seek treatment about twice as often.
  
• The peak age bracket for antidepressants is 50-64, with 15.5% yearly use. This is more than double the rate in the 18-34 bracket. This surprised me, maybe because of the influence of books like Prozac Nation (tagline - "Young and Depressed in America"). So, it looks like the increasing use of antidepressants is not because younger people, having grown up in the "Prozac Era", are more accepting of them.
  
• Antidepressants are a white thing - 12.0% of whites take them vs. about 5% of blacks and Hispanics. But it would be interesting to see a regional breakdown here. Are blue-state or red-state whites more likely to be medicated?
• Family income was not correlated with antidepressant use, but the unemployed were twice as likely to use antidepressants: 22% in '05. This might be because unemployment is bad for your mental health, or because mental illness is bad for your employment prospects. Or both.
  
• One of the questions in the survey asked people to rate their own mental health. Over 90% of Americans said it as "good", "very good" or "excellent" - including 80% of antidepressants users. This really surprised me, and suggests that these drugs are being prescribed to people who are not, overall, very unwell.
  
• The % of antidepressant users also using an antipsychotic drug rose from 5.5% to 8.9% in 2005. Given that the number of users also doubled, this means the number of Americans using an antipsychotic as well as an antidepressant increased by a factor of more than 3. This is worrying since antipsychotics are generally the worst psychiatric drugs in terms of side effects. While there is evidence that some of the newer antipsychotics can be of use in depression as an add-on to antidepressants, this is controversial and it's not clear that they're any better than the older alternatives, such as lithium.
  

Overall, this report verifies that antidepressant use has risen dramatically over the past several years. This is hardly news, but the magnitude of the increase is still startling.

What makes it especially interesting is that nothing much happened between 1996 and 2005 in terms of new antidepressants. A couple of new SSRIs, such as citalopram, were approved for sale in the US. But these drugs are very similar to Prozac (fluoxetine) which has been around since '87. Remeron (mirtazapine) hit the market in '96, but it's never been nearly as popular as the SSRIs.

So the change was a change in behaviour, a cultural or social phenomenon. For some reason, America decided to take more antidepressants. Books could be written on why this happened, and I hope they will be, because it's an important topic. But here's my personal take: the main reason why people are taking more antidepressants is that the popular concept of "depression" has become more broad. People have become more willing to label their experiences as "depression" and seek medical treatment. The notion that mental illness is extremely common - the one in four meme - is one aspect of this.

Finally, the inevitable caveats. The data here come from the Medical Expenditure Panel Surveys (MEPS) which were household surveys of "national probability samples of the US civilian noninstitutionalized population". This means that military personnel, the homeless, prisoners, and (presumably) illegal immigrants weren't included. And not everyone agreed to take part; the response rate was 70% in '96 but dropped to 60% in '05. On the other hand, the samples were extremely large (28,000 in 2005).

Olfson M, & Marcus SC (2009). National patterns in antidepressant medication treatment. Archives of general psychiatry, 66 (8), 848-56 PMID: 19652124

Bigmouth Strikes Again

In the Guardian, Oliver James gets his hands on some mental health statistics. As I have explained before, this rarely ends well. Zarathustra of the really wonderful Mental Nurse blog takes James to to task. Hilarity ensues.

[BPSDB]

Bigmouth Strikes Again

In the Guardian, Oliver James gets his hands on some mental health statistics. As I have explained before, this rarely ends well. Zarathustra of the really wonderful Mental Nurse blog takes James to to task. Hilarity ensues.

[BPSDB]

Everyone is Mentally Ill

There's been a lot of interest over the idea that an "Artificial brain is 10 years away", which is what Professor Henry Markram told the ultra-hip TED conference in Oxford the other day.

That's an amazing idea. But Markram said something else even more astonishing, which, for some reason, has not got nearly as much attention:

"There are two billion people on the planet affected by mental disorder," he told the audience.

Two billion people. One in three.

This was presumably a throw-away remark, something he said in order to emphasise the importance of understanding the brain. But this makes it even more amazing: we have reached the point where no-one bats an eyelid at the idea that mental illness affects one in three people worldwide.

Well, if this is what we believe now, I think we need to stop beating about the bush with numbers like one in four or one in three, and admit that we now are now using "mental illness" as a synonym for "the human condition".

After all, once you pass the point where one in two people have something, you are saying that it's normal and not having it is weird. As I've written before, if you take the evidence seriously, more than 50% of people are indeed "mentally" ill at some point. So let's just say that everyone is mentally ill and have done with it.

Or we could reassess what we mean by "mental illness" and stop medicalizing human suffering. Hey, we can dream.

Everyone is Mentally Ill

There's been a lot of interest over the idea that an "Artificial brain is 10 years away", which is what Professor Henry Markram told the ultra-hip TED conference in Oxford the other day.

That's an amazing idea. But Markram said something else even more astonishing, which, for some reason, has not got nearly as much attention:

"There are two billion people on the planet affected by mental disorder," he told the audience.

Two billion people. One in three.

This was presumably a throw-away remark, something he said in order to emphasise the importance of understanding the brain. But this makes it even more amazing: we have reached the point where no-one bats an eyelid at the idea that mental illness affects one in three people worldwide.

Well, if this is what we believe now, I think we need to stop beating about the bush with numbers like one in four or one in three, and admit that we now are now using "mental illness" as a synonym for "the human condition".

After all, once you pass the point where one in two people have something, you are saying that it's normal and not having it is weird. As I've written before, if you take the evidence seriously, more than 50% of people are indeed "mentally" ill at some point. So let's just say that everyone is mentally ill and have done with it.

Or we could reassess what we mean by "mental illness" and stop medicalizing human suffering. Hey, we can dream.

Questioning One in Four: Part 3

Welcome to the third and final post examining the idea that one in four of us suffer mental illness at some point in our lives.

As I explained in parts 1 and 2, "one in four" has no basis in the scientific literature, although given how dubious the literature is, this is not necessarily a bad thing. It's not clear where the one in four meme originally came from, although most of the recent uses probably trace back to a 2001 WHO report which quoted it.

But why has one in four proven so popular? The simple answer is that it's high, but not too high. Were someone to say that one in every two people suffer from mental illness, most of us just wouldn't believe it. That's actually what most published studies have found, but it fails the laugh test. One in four is low enough to be believable but high enough to be striking, attention-grabbing, and memorable.

Why are so many people quoting the highest estimate they can get away with? After all, if we've (unconsciously) decided that one in two is "too high", as we seem to have done, we could equally well decide that one in four is too high. We could redefine "mental illness" such that the prevalence of it was, say, one in ten, or one in fifty. Those would be no more and no less valid than one in four. But we haven't, so why not? There are some obvious, but wrong, explanations -

• Most obvious of all is Big Pharma. It's a well known fact that pharmaceutical companies are pure evil and that Satan sits on the board of directors of most them. And clearly, pharma do have a financial interest here. The more people who are deemed mentally ill, the more who might buy their pills. However, to think that pharma are primarily responsible for the spread of one in four is simplistic. Cynics that we are, no-one takes what pharma says seriously. At the least, they would need some accomplices to help convince people of the idea.
  
• People sometimes accuse governments of talking up prevalence estimates. The Szaszian phrase "the therapeutic state" still crops up, with the implication that the government wants to use mental illness as an excuse to implement authoritarian policies. Well. This conspiracy theory doesn't seem all that realistic, given that the present British government, at least, couldn't conspire to get drunk in a brewery. Indeed if anything, modern governments generally treat the mentally ill as a financial burden. They require often-expensive treatment, and maybe also welfare payments. At least in Britain, the government currently trying to minimize the numbers officially considered mentally ill, to save money.
• Finally, "Psychiatry" is said to be expanding its power by defining everyone as mentally ill. Anyone who has been to a psychiatry conference will find it hard to take the idea of such a grand plot seriously, but more fundamentally, this assumes that psychiatrists like treating people just for the sake of it. Why would they? In some countries, true, they do have a financial incentive to treat as many people as possible, although no more than any other medical professional. But in Britain and other countries with nationalized health-care, psychiatrists are paid a salary and every additional patient is just more work. And more chance of getting called up in the middle of a romantic dinner and having to talk down some suicidal person for three hours.
  

The true explanation, I think, is rather more boring than any of the above. Simply, one in four persists because everyone with an interest in talking about the prevalence of mental illness has an interest in talking it up.

Mental health charities and other advocates for the mentally ill like one in four because it's a great way of fighting the stigma attached to mental illness. One in four represents hard, scientific proof that mental illness is not rare, weird, and freakish - i.e. that the mentally ill are "just like everyone else" and have the same rights. Which is a perfectly good message, and remains one despite the fact that one in four is rubbish.

Academics like one in four - or rather, like high estimates of the prevalence of mental illness - because it gives their work an air of importance. Almost every research paper about depression, for example, starts with a paragraph of formulaic boilerplate to the effect that "Depression is really common". Here's the first paragraph of the first depression paper I plucked from PubMed at random (honestly) -

Major depression is a substantial public health problem, ranking first among the causes of worldwide disability. According to a study by the World Health Organization, depression was estimated as fourth leading cause of disability-adjusted life years (DALYs), a measure of disease burden, in all age groups and the second leading cause in people aged 15–44 years in 2001 (World Health Report, 2001). Lifetime incidence and prevalence estimates are not available for the UK or Scotland (Paykel et al., 2005). The one year prevalence for major depressive disorder (MDD) in Europe has been estimated at 3.9%, 5.0% in women and 2.6% in men (...). A large proportion of these patients remain untreated despite a number of campaigns aiming at increased awareness of depression.

This doesn't quote one in four as such (academics rarely do), but you can see why these authors and everyone else are not exactly lining up to debunk it. I'm not accusing the authors of this paper of being deliberately disingenuous; I'm sure they believe what they wrote. But they wrote it and made it their first paragraph for a reason. It's a running joke in modern science that when you're applying for grant money or trying to get work published, you have to talk up the "practical implications" of your research. In medicine a crucial aspect of this is talking up the seriousness and importance of the disease you're studying.

So, one in four persists because it's in no-one's interest not to say it. There's no conspiracy, just the collective action of various groups all of whom benefit from the idea that mental illness is extremely common. Fascinatingly, the very same mental health charities (and pop psychologists) who are traditionally opposed to academic psychiatry and Big Pharma have ended up promoting statistics which perfectly serve the interests of those groups. Not on purpose, of course. No-one is trying to be deceptive, everyone is just doing what they think is the right thing - but the end result is that this profoundly dubious statistic has become almost universally accepted.

[BPSDB]