Prevalence and underrecognition of dysthymia among psychiatric outpatients in São Paulo, Brazil.

Background: Dysthymia is a highly prevalent disorder with rates varying from 3 to 6%. It is estimated that 7% of primary care and up to 36% of the psychiatric outpatients have this disorder. Dysthymia is characterized by a pattern of low intensity and long duration depression, leading to impairment in many aspects of the patient's life (work, family).