THE recent World Health Organization (WHO) report Investing in Health Research and Development predicts that depressive illness will be the single most important cause of disability in the developing world. Many health researchers may be amazed and even skeptical about the validity of this prediction. However, this report is only the latest such warning. The World Bank Development Report of 1993 found that depression and other psychological disorders were second only to heart disease, as the most important non-communicable causes of disability. Indeed, the warning of a mounting crisis of unmet needs for the countries' millions with depressive and anxiety disorders, have been building up over the past 20 odd years with evidence of a high prevalence of common psychological disorders in both developed and low-income countries.
Cause for worry Studies from diverse settings ranging from rural Lesotho and the slum in Sao Paulo to the urban population in India reveal prevalence figures of depression and anxiety exceeding 30 per cent in community samples and approaching 50 per cent in primary health care samples. The high, and potentially rising, prevalence of depression is of concern for three reasons. First, the social factors known to be linked to depression are on the increase throughout the developing world as the formula for economic development adopted by many countries is leading to a reduction in public health expenditure, a rising inequality between rich and poor, increased migration to urban areas with its attendant rise in urban squalor and rapid culture change as the great urban centres take on an international cosmopolitan flavour. Studies from countries as diverse as Chile, Brazil, Zimbabwe and India show that women and those who are facing socio-economic problems, such as the unemployed and low-wage earners, are at greater risk to such disorders.

The well established association between depression and disability, independent of any co-existing physical illness, is the second reason. Depression causes a profound disability by robbing the afflicted of the desire to live, the energy to work and hope for a better future. Thus, those who are already vulnerable due to their gender or social circumstances risk being afflicted by a disorder that will further disable them and render them less able to cope with the adverse circumstances that they already face. Finally, even though many individuals with depression feel so ill that they consult doctors more frequently, most remain untreated because of improper diagnosis. Commonly, such patients are given a cocktail of oral and injectable treatments and the root social causes of the illness remain unaddressed. Indeed, depression is rarely even mentioned by policy-makers, development agencies or grassroots NGOs in their agendas for public health issues facing the developing world.

A key, reason for the low priority accorded to depression is the nature of the medical specialty of psychiatry which has been pr4foundly influenced by European and American systems of philosophy and science. This remains an alien subject not only to the lay communities of the low-income world but to their medical fraternities as well. Most people, including physicians, associate psychiatry with lunacy and insanity and both depressed patients and their guardians are unwilling to associate themselves with the stigma attendant to the severely mentally ill. Psychiatrists in low-income countries have, for the most part, remained confined to hospital care settings where the majority of their patients suffer from mental disorders with obvious behavioural symptoms.

Many community-based programmes focus on psychoses, mental handicaps and epilepsy. The concept of the multidisciplinary team is rarely utilised. Even though the vast majority of depressed individuals rarely consult psychiatrists and often consult primary health workers, there is little dialogue between mainstream psychiatry and primary care health workers. Thus, the image of psychiatry and the clinical setting of its practitioners serve to exclude depression from the mainstream of primary health care. There is a need to adapt psychiatry to fit with the conceptual models of mental illness in the community rather than to blindly adopt the classifications developed with a largely European bias.
Misunderstood affliction The choice of priorities in primary health care is often influenced by the perceived severity and potential benefit from therapeutic interventions. Depressive and anxiety disorders have not been considered as priorities for a number of reasons: they were so common that they could risk overwhelming primary care staff, they were too minor to justify being prioritised in settings with considerable severe physical illness morbidity; they were so transient that most persons improve regardless of intervention; there was little a primary health worker could do when the causes of depression were often socio-economic or interpersonal and beyond the reach of the health worker; and, finally, of all mental disorders, depression was the mildest, and severe disorders such as the psychoses were more 'deserving' on the priority list.

While it is true that depression is very common, it seems absurd that this should be taken as a reason for not prioritising it; indeed the overwhelming evidence shows that depression is common and disabling and thus it being labelled as a 'minor'. mental illness or the view that it is transient is misleading. There is a perception that diseases which kill are more 'serious' and the psychological disorders are a 'luxury' for poor people. Nothing could be further from the truth. Depression can kill in a number of ways, most dramatically through suicide. Further, recent long-term studies have shown a high mortality rate in patients with a depressive illness due to causes other than suicide as well. This may be due to the well recognised link between depression and poor prognosis of physical illness.

Depression is not a luxury for the poor; indeed, they are more likely to suffer the illness, less to receive any effective treatment and, worse, will probably spend precious money consulting a host of doctors and alternative medical practitioners to alleviate their suffering. The argument that there is much physical illness distracts from the finding that those who are depressed are consulting health services already and simply ignoring them will not make them disappear. If anything, these patients will consult in greater numbers and as serious physical illness is often associated with psychological reaction, which in turn may worsen the outcome of the illness, the notion that physical illness should have a priority is simplistic and ignores the holistic nature of health in primary care.

While it is clear that the root cause of many depressive illnesses i4 socio-economic deprivation, this does not imply that the health worker can do little to help the patient. An analogy may be made with common infectious diseases such as tuberculosis and diarrhoeas, which are the priority of primary care in low-income countries; these are as much influenced by poverty and, indeed, the eradication of these diseases from developed societies had much more to do with the provision of clean drinking water and healthier living circumstances than drug treatments. However, this has not stopped primary health care from actively treating these diseases; similarly, the primary health worker has the opportunity to use simple behavioural interventions or antidepressants which may provide relief from some of the unpleasant symptoms of depression. It is true that psychoses are the most disturbing of mental disorders. However, these are relatively uncommon and in many low-income societies, patients are often taken directly to tertiary facilities, bypassing primary care altogether. Further, these are the very illnesses for which specialist psychiatric care is probably most appropriate and for which primary care facilities are often inadequate.

Depression is a universal human affliction in response to loss and demoralisation. It has a clear biological component, but social, economic and cultural factors play a key role in influencing its course and outcome. It is not associated with mental illness in the same way as schizophrenia or mania, but its sufferers feel ill and do consult primary health workers in huge numbers. By disabling the person and by making them consult health services more often and for longer periods, depressive illnesses have a profound impact on the productivity of the individual and on health care costs. The indifference of public health policies, development agencies and the vast majority of health workers in developing countries means that the suffering of millions with depression today remains a silent and expensive one. There are concerted programmes to tackle depression in primary care throughout the industrialised world, involving close cooperation between primary workers and psychiatrists and with the active support of policy-makers. There is an urgent need, therefore, to evaluate the extent, outcome and management M of depression in low-income countries, not only to help those who are already crippled by this pervasive illness but, at the very least, to acknowledge their suffering.

Vikram Patel is a Goa-based psychiatrist