[Epidemiology of mood disorders].

The 12 months and lifetime prevalence of is respectively 5 and 9% in the general population; moreover 10 to 20% of general practice patients are depressed. Depression is involved in about 40 to 80% of suicide and induces one of the greatest social burden. Mood disorders are more frequent in women, individual living alone and people with low socio-economic level. Risk factors are stressfull life events, biological vulnerability (genetic factors), somatic diseases, psychiatric comorbidity including personality disorders and addictions. Depressive disorders are underdiagnosed and undertreated despite efficacious pharmacological and psychotherapeutic strategies in their treatment. It's the reason why public health programs to prevent depression have been promoted by many countries like European Alliance against Depression. Their efficacy must be evaluated as their cost-efficiency.