In writing this blog I want to try and cover some of the stories that are missed by other science blogs, and also to reinforce the link between science and the wider world, to show that research affects our day-to-day policies. In that spirit, I thought I'd share with you a paper just published in PLoS, that looks at the effect of the Arab-Israeli conflict on an Arab population - "Lifetime Prevalence of Mental Disorders in Lebanon: First Onset, Treatment, and Exposure to War" [1].

In the United Kingdom, about a quarter of people suffer from mental illness - defined as "persistent problems with thinking, with feelings, with behavior, and with coping with life" at some time in their lives, and this figure rises to a disturbing 50% in the United States. In these and other Western nations mental health is a thriving research area, but according to Karak et al, data on mental illness in the Arab world is sparse to non-existent. Indeed, in the world generally, data on mental illness is hard to come by.

This lack of data isn't just important for the populations it affects, but for mental health research in general. There are two reasons in particular why this is so: firstly, with such a large gap in our data it's impossible to put our own mental health into a wider context - to see if our figures are normal or unusual; secondly, we have little idea of what sort of impact events like war have on mental health, beyond the simple and potentially unhelpful assumption that it is a negative one. In order to try and address this problem, the World Mental Health Initiative has been set up, to undertake large-scale surveys in more than 29 countries. This study, in Lebanon, is part of that work.

The methodology used is open to a couple of criticisms. The team's approach was to interview a representative sample of 2,857 adults using a standardized test that classifies mental health according to DSM-IV codes (see a list of codes here). DSM-IV, or more fully the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, is a manual that sets standard diagnostic criteria for all known mental health disorders, produced by panels of psychiatric experts. The researchers here employed the World Health Organizations Composite International Diagnostic Interview, which produces DSM-IV codes as an output.

The first issue with this is sample size. The authors themselves admit that "The initial target sample (3,000 interviews) was set by WHO as the minimum needed to obtain sufficient level of precision for WMH participation". The actual sample size of 2,857 falls slightly short of this recommended minimum, and although this short-fall is unlikely to have a big impact on the results it is slightly unfortunate.

The second criticism concerns the test itself. Mental health diagnosis is a controversial and tricky subject at the best of time, and so it should come us no surprise to hear that the DSM-IV standards have come in for some heavy criticism. Cosgrove et al in particular are scathing of the composition of the expert panels used to decide on the diagnostic criteria [2]: "Of the 170 DSM panel members 95 (56%) had one or more financial associations with companies in the pharmaceutical industry. One hundred percent of the members of the panels on 'Mood Disorders' and 'Schizophrenia and Other Psychotic Disorders' had financial ties to drug companies. The leading categories of financial interest held by panel members were research funding (42%), consultancies (22%) and speakers bureau (16%)."

Putting those relatively minor criticisms aside, what did the researchers find? Roughly a quarter of the respondents in the survey had experiences one or more mental health disorder at some time in their lives. Extrapolating from this data, they calculated that by the age of 75 years mental illness would affect up to a third of Lebanese, major depression being the most common disorder experienced. Treatment rates were very low, even though Lebanon has a ratio of doctors/population similar to that of most industrialized nations, and the average delay in seeking treatment ranged from 6 years for mood disorders up to a spectacular 28 years for anxiety problems. Exposure to war-related events increased the risk of developing an anxiety, mood, or impulse-control disorder by about 6-fold, 3-fold, and 13-fold, respectively.

These figures aren't likely to be very precise due to the difficulty both of diagnosing mental illness (especially in a culture where admitting mental health problems may be a taboo), and of assessing the level of exposure of individuals to events such as wars. Nonetheless they give us a useful "rough guide" to mental health in the country, and raise some interesting questions. Clearly there is a lot more work to do in this area to build a bigger, better picture.

What I find particularly interesting though is that the prevalence of mental health in a nation such a Lebanon, that has been exposed to regular upheaval, violence and war over the last few decades, is not substantially different from the figures we have for Britain and the United States. Indeed if this result is accurate, Americans seem to be more vulnerable to mental health issues than populations in the Middle East. If the World Mental Health Initiative surveys continue to show this trend, then we'll have to start asking some fundamental questions about why our secure, Western lifestyles don't appear to be calming our minds, or reducing diagnoses. Are we really as stressed as the inhabitants of a war-torn nation, or are conflicts of interest and a culture of medicalization leading to too many false positive diagnoses?

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[1] Karam, E.G., Mneimneh, Z.N., Dimassi, H., Fayyad, J.A., Karam, A.N., Nasser, S.C., Chatterji, S., Kessler, R.C., Murthy, R.S. (2008). Lifetime Prevalence of Mental Disorders in Lebanon: First Onset, Treatment, and Exposure to War . PLoS Medicine, 5(4), e61. DOI: 10.1371/journal.pmed.0050061

[2] Cosgrove, L., Krimsky, S., Vijayaraghavan, M., Schneider, L. (2006). Financial Ties between DSM-IV Panel Members and the Pharmaceutical Industry. Psychotherapy and Psychosomatics, 75(3), 154-160. DOI: 10.1159/000091772