Mental Illness vs. Suicide

By Neuroskeptic | November 25, 2009 1:00 pm

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.

ResearchBlogging.orgSartorius 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

CATEGORIZED UNDER: 1in4, graphs, mental health, papers, surveys
  • http://www.blogger.com/profile/01409693747482226529 Pallas

    There obviously should be more of a stigma against suicide in some countries than other- the Japanese famously used to endorse suicide in certain situations, so their higher suicide rate is not unexpected.

    Kind of odd that some countries might have more mental illnes” than others. I wonder how that tracks diagnosis of non mental illness?

  • Glenn

    I agree with Pallas. You seem to be neglecting the powerful effect of culture. I think it is no coincidence that the lowest suicide rates are found in predominantly Roman Catholic countries. If you had data on Muslim countries you would also find that they have relatively low suicide rates. That fact that China is Confucian and Japan is “shame-based” collectivist may also play a role. National stereotypes have validity at the population level — we often think of the fatalistic Eastern Europeans (and the suicide rates in Hungary and the Czech Republic and Moldavia are also quite high, as with Ukraine). I would be very interested to see if the suicide rates in Belgium vary by region, as it does in the United States — where relatively isolated, harder drinking, gun-owning men in the Western states consistently kill themselves at higher rates than their city-dwelling and suburban Northeastern cousins.

  • http://www.blogger.com/profile/06647064768789308157 Neuroskeptic

    Sure, there are no doubt lots of cultural and socio-economic determinants of suicide. But on an individual level mental illness is a very strong predictor, which implies that there should be some correlation internationally if 12 month prevalence of mental illness really varies by a factor of 7 between countries (4% to 27%)! But there isn't. Now I don't know much about suicide but this to me suggests that our methods of measuring mental illness are way off.

  • http://www.blogger.com/profile/06832177812057826894 pj

    Or methods to measure suicide suck. It is certainly the case that in the UK there is a real pressure not to class apparent suicides as such – indeed studies of suicide often include 'unexplained' deaths to get a more accurate estimate.

    If these trends vary across countries this could easily mask any relationship.

  • Michael Levin, MD

    Apologies for the length of the quote:

    http://www.medindia.com/news/Finlands-Suicide-Rates-Has-Dropped-Dramatically-in-Last-15-Years-26447-1.htm

    Finland's Suicide Rates Has Dropped Dramatically in Last 15 Years
    Category: Mental Health News
    Sunday, September 16, 2007 at 11:49:11 AM

    Finland has finally shed a bleak record as one of the world's suicide capitals after the number of people taking their own lives in this Nordic state has dropped by 40 percent in the past 15 years.

    Nowadays around 18 out of 100,000 people commit suicide each year in Finland, about the same level as in France and Austria. In 1990, the number was 30 per 100,000.

    The decline is attributed largely to better treatment for depression, but even experts cannot really explain why the drop has been so dramatic, admits psychiatrist Jouko Loennqvist, the head of the mental health department of Finland's National Public Health Institute.

    Finland's dire reputation as a nation of suicidals dates back to the 25-year period from 1965 to 1990 when Finland experienced an economic and urban boom.

    During that period, the suicide rate tripled.

    By 1991, Finland was the world leader in teen suicides, and among the top three in overall suicides alongside New Zealand and Iceland.

    Faced with the grim figures, Finnish authorities dramatically increased funding to improve mental health and since 1991 the amount of available psychiatric help has doubled.

    “We also have a lot of new antidepressantdrugs (which are) easy to use, whereas until the late 1980s and beginning of the 1990s, practicians usually gave patients anxiolytics (anti-anxiety drugs) and sedatives,” Loennqvist said.

    Awareness campaigns in schools and among military conscripts also seem to have paid off, as the suicide rate among adolescents and young adults has dropped by 30 percent since 1991.

    But the suicide rate is still high among young men — it is the main cause of death among males aged 20 to 34.

    The typical profile of a Finnish suicide victim is a man in his 40s, divorced and unemployed, alcoholic and in poor health.

    In addition to traditional risk factors such as depression, alienation, personal problems and unemployment, Finnish researchers single out alcoholism as the biggest single risk factor.

    However, “half of all suicides are linked to alcohol, and one-third of all suicides have been (committed by) alcohol-dependent persons,” Loennqvist said.

    Finns drink the equivalent of 10 liters (2.64 gallons) of pure alcohol per year per person, according to figures from the World Health Organization from 2004.

    That's less than the French, who drink 14 liters, but more than Swedes or Norwegians who drink seven and six liters respectively.

    Source-AFP

  • http://www.blogger.com/profile/06647064768789308157 Neuroskeptic

    pj: That's a fair point. I wasn't aware that there was a not-suicide pressure in the UK, though – I'd always thought it was more a Catholic country thing, for example – why do you think it is?

    Another possible source of noise here is age. In some countries the samples for the % mental illness estimates had maximum ages (54 and 65 most commonly), but suicides of course occur at every age and older people have higher than average risk at least in the US.

  • http://www.blogger.com/profile/03967880334983173725 Mike Eslea

    The point about attempted suicide is interesting. Could some of the differences be down to the different methods people choose in different countries? Maybe the typical Japanese suicide attempt is more likely to succeed. Apparently (sorry, I don't have a ref for this) men are more likely to succeed than women because they opt for spectacular messy suicides rather than slow overdoses, wrist slashing etc. I wonder if there are any cross-national stats for different methods?

  • http://www.blogger.com/profile/06832177812057826894 pj

    “why do you think it is?”

    I think the idea is that the family would prefer their child/parent etc died in an accident rather than by suicide – death statistics are quite heavily manipulated, for example the pressure to not put HIV/AIDS on a death certificate is immense and most certs are simply guesses (which inflates, for example, MI rates).

    Mike's point about different methods is very interesting – I reckon he's onto something there, there is definitely a big difference between different methods as reflected in the difference between men and women.

    On the question of age – the highly lethal suicide attempt by the elderly male is a staple of psychiatry in the UK too.

  • dearieme

    “I wasn't aware that there was a not-suicide pressure in the UK, though … why do you think it is?”
    The sentimentality that is part of the juvenalisation of society?

  • http://www.blogger.com/profile/01908959102563134458 Rolfa

    You acknowledge, in the opening paragraph, that 'not all suicides are related to mental illness'. This might be rather an understatement; research in the UK suggests only about a quarter of people who commit suicide have had contact with mental health services in the year before death. (http://www.bmj.com/cgi/content/abstract/318/7193/1235).

    Given that three-quarters of suicides seem to have causes other than mental illness, maybe it's not surprising you don't find a correlation?

  • http://www.blogger.com/profile/06647064768789308157 Neuroskeptic

    Rolfa – Hmm, interesting paper, I hadn't seen that. But I have read in other papers (e.g. the one I linked to) that about 90% of suicides were suffering from a diagnosable mental illness at the time of death.

    This implies that a lot of people were ill but not in contact with mental health services – which I can easily believe (maybe that's why they were suicides – if they'd been treated they'd have lived).

    However it could also be an overestimate because I think the 90% figure relies on “psychological autopsies” i.e. retrospective evaluations. I don't know how valid they are.

  • Janis

    What struck me was how — within some limits — the hotter, sunnier countries had the lowest suicide rates. *shrug* It just seems to make sense that the Scandinavian countries would have high suicide rates and places like Spain and Greece wouldn't. Three hours of sunlight a day in the winter can do that to a person. So I'm not sure it's a Catholic thing, just a hot-weather-long-summer thing, maybe … ?

  • Anonymous

    Interesting Article, I wish that this research was done on the military deployed abroad. Last year the Army alone had a major increase in suicides. The military has aloud many young Americans with “mild” mental disorders to serve their country thru waivers. Most of those have attempted suicide or have contemplated it.
    I know that this topic has been discussed because we don not let these individuals in the military anymore. I would love to see the comparisons. Very interesting article.

  • http://tokyocounseling.com Andrew Grimes JSCCP, JCP

    Over the last ten years a lot of progress has been made in overcoming the traditional stigma against admitting to either having a mental illness or admitting to others outside your family that someone in your family is suffering from and/or dealing with a mental illness in their lives. This is particularly true with regards to greater acceptance of depression and anxiety disorders. However, despite the progress in this area and more people being willing talk about depression and more public debate in the Japanese media on this issue, official figures do yet seem to reflect the fact of the high incidence of these and other mental illnesses in Japan.

    Here in Japan it is definitely the case that depression is a massively under-diagnosed mental illness and even according to the Ministry of health estimates and studies only 25% of those who suffer with depression are diagnosed or receive any treatment at all. Other estimates put the numbers of people here suffering from depression in the millions. Mental illnesses in Japan are in fact very high but this does not show in official figures and so does not show up in a statistical analysis to the degree it should.

    Mental health professionals in Japan have long known that the reason for the unnecessarily high suicide rate in Japan is due to unemployment, bankruptcies, and the increasing levels of stress on businessmen and other salaried workers who have suffered enormous hardship in Japan since the bursting of the stock market bubble here that peaked around 1997. Until that year Japan had annual suicide of rate figures between 22,000 and 24,000 each year. Following the bursting of the stock market and the long term economic downturn that has followed here since the suicide rate in 1998 increased by around 35% and since 1998 the number of people killing themselves each year in Japan has consistently remained well over 30,000 each and every year to the present day.

    The current numbers of licensed psychiatrists (around 13,000), Japan Society of Certified Clinical Psychologists clinical psychologists (19,830 as of 2009), and Psychiatric Social Workers (39,108 as of 2009) must indeed be increased. In order for professional mental health counseling and psychotherapy services to be covered for depression and other mental illnesses by public health insurance it would seem advisable that positive action is taken to resume and complete the negotiations on how to achieve national licensing for clinical psychologists in Japan through the Ministry of Health, Labour and Welfare and not just the Ministry of Education as is the current situation. These discussions were ongoing between all concerned mental health professional authorities that in the ongoing select committee and ministerial levels that were ongoing during the Koizumi administration. With the current economic recession adding even more hardship and stress in the lives its citizens, now would seem to be a prime opportunity for the responsible Japanese to take a pro-active approach to finally providing government approval for national licensing for clinical psychologists who provide mental health care counseling and psychotherapy services to the people of Japan.

    Some useful telephone numbers and links for residents of Tokyo and Japan who speak Japanese and/or Engish and are feeling depressed or suicidal and need to get in touch with a mental health professional qualified in Japan:

    Inochi no Denwa (Lifeline Telephone Service)
    Japan: 0120-738-556
    Tokyo: 3264 4343

    AMDA International Medical Information Center:
    http://amda-imic.com/

    http://www.counselingjapan.com

    All the best from Tokyo!

    Tokyo Counseling Services:

    http://tokyocounseling.com/english/
    http://tokyocounseling.com/jp/

  • http://www.panicaway.com Barry McDonagh

    Most surveys have a limiter number of respondents. It may be impossible for them to get responses from even 10% of the total number of people who have documented cases of mental illness, as there are too many to survey.
    Thanks for sharing

  • http://www.blogger.com/profile/01087601235530226889 A Bitter Pill

    I'm sure there are complex sociocultural factors, but I shall not speculate as to what they are. Just a simple point: People with mental illness have a higher rate of suicide, but what portion of completed suicides have mental illness? Is it only a small subset? I don't know, but I think a great deal of suicides happen during drastic life changes, end-of-life, severe medical/pain problems, under-the-influence, or during adolescence (a natural force much more severe than simple mental illness). Another factor, regardless of mental illness, is social network/family versus isolation. Economically modern society promotes isolation. This factor increases with economic prosperity and decreases during economic depression when people are more likely to lean on family.

    It is an interesting fact that places like China and Philippines that do not have “modern” mental health systems or general availability of late generation psych meds have low rates of both depression and suicide. Go figure.

    So, should we be exporting First-World expertise when we clearly don't have a handle on what's really going on?

  • http://www.femaleejaculatorydischarge.org/ Female Power

    Although the findings may display that there is no correlation to mental illness and suiside, I am extremely suspect. I have a feeling that the number of diagnoses for mental illness in the US is perhaps higher than other countries because of the laiser faire attitude with diagnoses in the US. I also suspect that mental illness in Asian countries like Japan are likely under diagnosed.

  • http://www.tabletpc-shop.info tablet pc

    Thank you for the post, really useful data.

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Neuroskeptic is a British neuroscientist who takes a skeptical look at his own field, and beyond. His blog offers a look at the latest developments in neuroscience, psychiatry and psychology through a critical lens.

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