[Severe depression : concomitant somatic disease]

The association of somatic disease with a depressive disorder is not uncommon and affects 25% of general hospital inpatient populations. Although not well incorporated into management it is a source of mutual worsening of the two diseases. Several questions arise with this association. Firstly, it is essential to establish whether the depressive disorder is primary or secondary as these situations occasionally involve different (and even opposite) diagnostic and treatment approaches. It is then important to establish whether or not the disorder is adaptatory in nature : although an adaptatory problem does not have the same impact as depression on somatic outcome, it can progress to endogenous depression. Finally it is essential to identify the extent of suicidal risk, which is not only due to the depression but more to the feeling of despair (which is common in patients suffering from severe somatic illness). We will then examine the severity of these interlinked depressions in terms of the diagnostic difficulties (from confusion of symptoms to considering them to be unimportant). We shall then describe all of the consequences of the somatic disease on the prognosis of the depression and vice versa. Finally we will examine the question of severity from the perspective of the most widely studied associated diseases. Whilst the presence of an incapacitating somatic disease is a risk factor for depression in these vulnerable people, depression associated with the different major somatic diseases is a poor prognostic indicator. Somatic co-morbidities are still underestimated and are a factor responsible for chronic progression, deterioration and increased risk of suicide.