Why are so many people suffering from depression?

The Arabian Peninsula nations have had only a handful of studies on the prevalence of psychological disorders.

This type of research is valuable in the planning of health services. By shedding light on risk factors, these studies can encourage forms of intervention aimed at early detection and illness prevention.

The few studies to date suggest an alarmingly high prevalence of depressive illness in the region. The most recent and most robust of these studies was done in Qatar; the findings were published last year in the Journal of Social Psychiatry and Psychiatric Epidemiology.

The findings, like those of earlier studies, paint a fairly bleak picture. Researchers looked at 1,660 Qatari adults who visited primary health care centres.

To ensure the validity and reliability of the findings, the study used multiphase screening. This means that first health care professionals screened the subjects, using a common, well-validated method to identify individuals with high levels of depressive symptoms. Then came phase two, formal evaluations by two independent senior psychiatrists. A diagnosis of depressive illness was made only if the two psychiatrists agreed.

This fairly robust methodology makes the findings all the more difficult to ignore:

In the first phase, 26.6 per cent of males and 30.1 per cent of females were deemed to have depressive-symptom scores above the cut-off level. In other words, more than a quarter of Qatari adults receiving routine health care are experiencing clinically significant levels of depressive symptoms.

After the second phase, 13.5 per cent were formally diagnosed as experiencing a depressive disorder.

The American Psychiatric Association suggests that the "prevalence" of major depressive disorder is normally between 3 and 5 per cent of adults. "Prevalence" here means the proportion of people experiencing depression at the time of the study. However, depression tends to be episodic and recurrent, so estimates of "lifetime prevalence" (the percentage of individuals who have ever experienced the illness) are generally higher, and perhaps more meaningful. The Qatari study used point-in-time prevalence.

One explanation is that the subjects were all receiving health care. We generally find higher rates of depression among patients.

However, even when we compare the Qatari data to findings from parallel studies in other countries, the 13.5 per cent rate is still at the very high end.

In one recent European study of primary-care patients from six nations, the rate for men was 8.5 per cent, and for women 13.9 per cent. The highest rates were in the UK and Spain. The Qatari data is on a par with the study's UK rates: 12.7 per cent for males, 13.2 for females.

Risk factors for depression in the Qatari study included being female, being more highly educated and being age 18-34.

Health economists bemoan depression because of its impact on occupational functioning. In the US, the annual cost of depression, based on data from 2000, was $83.1 billion (Dh305bn). Of this cost, 62 per cent, involves lost working days. Only 31 per cent of the price tag was related to direct medical costs.

The World Health Organisation's Global Burden of Disease study says that in terms of the costs arising from lost productivity, depressive illness is the world's fourth-most-serious burden. The WHO predicts that by 2030 depression will become the world's number-one problem in this regard.

The debilitating effect of depression on motivation makes it particularly challenging for Gulf nations that are aggressively pursuing programmes of workforce nationalisation. Initiatives aimed at reducing the prevalence of this condition are critical to nations with youthful populations and ambitious developmental plans. Further research is required, especially research focused on reducing the prevalence, duration and frequency of severe depressive episodes.

My own research, supported by the Emirates Foundation, is looking at depression, stress and anxiety among Gulf residents.

This study, popularly known as the Arabia Felix Project (from the Latin meaning "happy Arabia") can be accessed at www.arabiafelix.ae. Your participation would be appreciated.

Justin Thomas is an assistant psychology professor at Zayed University in Abu Dhabi.