Mood disorders: epidemiology and natural history

This paper outlines epidemiology and natural history of mood disorders. It points out that in addition to classical syndromes of depression and mania there are also other mood syndromes with different epidemiology and natural history involved. New epidemiological studies considering broader definitions of bipolar mood disorders show that lifetime prevalence is much higher than formerly assumed (3–6% of the population). Mood disorders are severe and chronic diseases, most of which could be considered lifelong disorders. The occurrence of bipolar disorders is about twice that of depression. Patients with mood disorders have a higher risk of death by suicide (15–30%) than healthy people. The mortality is also higher than that of the general population (e.g. due to cardiovascular diseases). It is still uncertain whether modern treatment methods have substantially changed the length of episodes or the number of relapse of mood disorders.