Sleep and depression - theory and practice

BACKGROUND: Sleep disorders are particularly common in the primary care setting, and are intimately interlinked with depression. OBJECTIVE: This article aims to review the relationship between sleep and depression, with an emphasis on the foundation and clinical salience of this relationship. DISCUSSION: Depression is the most common cause of insomnia, and insomnia is highly prevalent in depression. This association has a well characterised physiological foundation. Sleep disorder in depression has prognostic and therapeutic implications. Residual insomnia after remission of depression is predictive of relapse, and prominent insomnia predicts a poorer treatment outcome in depression. Evidence based management involves integrating both pharmacological and behavioural strategies; the latter includes sleep hygiene and regulating diurnal rhythms.