Introduction: Depression may affect up to 10% of the population, with half of affected people having recurrence of their symptoms. In mild to moderate depression, there is no reliable evidence that any one treatment is superior in improving symptoms of depression, but the strength of evidence supporting different treatments varies. In severe depression, only prescription antidepressants and electroconvulsive therapy are known to improve symptoms.
Methods and objectives: We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of treatments in mild to moderate and severe depression, and in treatment-resistant depression? Which interventions reduce relapse rates? We searched: Medline, Embase, The Cochrane Library and other important databases up to April 2006 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
Results: We found 87 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
Conclusions: In this systematic review we present information relating to the effectiveness and safety of the following interventions: antidepressant drugs (tricyclic antidepressants [including low-dose tricyclic antidepressants], selective serotonin reuptake inhibitors, monoamine oxidase inhibitors, reboxetine, or venlafaxine), continuing prescription antidepressant drugs, electroconvulsive therapy, exercise, lithium augmentation, pindolol augmentation, St John's Wort.