The vital importance of the mental health of a nation for the overall well being of the population and socioeconomic development is increasingly recognized. In Malaysia, psychiatric disorders were responsible for 8.6% of the total Disability Adjusted Life Years and were ranked fourth as the leading cause of burden of disease by disease categories1. More and more evidence shows that physical illnesses are strongly associated with psychiatric disorders. Those with physical illnesses have much higher risk of developing psychiatric disorders compared to that without2-3. The mechanisms of co-morbidity of psychiatric and physical illness are complex. It is a two-way interaction and there are five different possible ways to describe this4-5.

Co-incidence or By-chance

In clinical practice, the psychiatric illness may be coincidental and unrelated to physical problems, as both physical and psychiatric conditions are common in the general population. Such disorders do, however, complicate the management of the physical illness. For example, depression can predate the onset of the medical illness in up to 25% of patients with co morbid depression, and it is associated with an increase in somatic complaints5.

Common cause for both

Here, either patient factors or non-disease factors may have given rise to both; for example, stressful life events in a vulnerable person may precipitate both a stroke and a depressive illness6.