Severity of depressive episodes during the course of depressive disorder

Abstract

Background: It is not clear whether the severity of depressive episodes changes during the course of depressive disorder. Aims: To investigate whether the severity of depressive episodes increases during the course of illness. Method: Using a Danish nationwide case register, all psychiatric inpatients and out-patients with a main ICD-10 diagnosis of a single mild, moderate or severe depressive episode at the end of first contact were identified. Patients included in the study were from the period 1994-2003. Results: A total of 19 392 patients received a diagnosis of a single depressive episode at first contact. The prevalence of severe depressive episodes increased from 25.5% at the first episode to 50.0% at the 15th episode and the prevalence of psychotic episodes increased from 8.7% at the first episode to 25.0% at the 15th episode. The same pattern was found regardless of gender, age at first contact and calendar year. Conclusions: The increasing severity of depressive episodes emphasises the importance of early and sustained prophylactic treatment. Declaration of interest: None.