Risk factors for chronic depression--a systematic review.

Area of Science:

• Psychiatry
• Clinical Psychology
• Epidemiology

Background:

• Approximately 20% of patients with acute depressive episodes develop chronic depression.
• Risk factors contributing to the chronicity of depressive episodes are not well understood.
• This review systematically investigated factors associated with the development of chronic depression.

Purpose of the Study:

• To identify risk factors for the progression of a current depressive episode to chronic depression.
• To synthesize evidence from existing literature on predictors of depression chronicity.

Main Methods:

• A comprehensive literature search was conducted across multiple databases (Medline, Psycinfo, Web of Science, CINHAL, BIOSIS) up to September 2007.
• Handsearching of the Journal of Affective Disorders and reference list reviews supplemented the database search.
• Two independent investigators applied a formal checklist to determine study eligibility, including 25 primary studies with 5192 participants.

Main Results:

• Identified risk factors for chronic depression include younger age at onset, longer duration of depressive episodes, and a family history of mood disorders.
• Psychological comorbidities (anxiety, personality disorders, substance abuse), low social integration, negative social interactions, and lower symptom severity were frequently associated with chronic depression.
• The methodological quality of the included studies was generally sufficient, with data synthesized via vote counting.

Conclusions:

• Key risk factors for the development of chronic depression have been identified.
• The majority of included studies were cross-sectional, limiting the ability to draw definitive causal conclusions.
• Further longitudinal research is needed to establish causality and refine understanding of depression chronicity.