A Meta-Analysis of Cognitive-Behavioural Therapy for Adult Depression, Alone and in Comparison with other Treatments

Summary & key facts

Researchers combined results from many studies to see how well cognitive-behavioural therapy, or CBT, helps adults with depression. They looked at about 115 studies and found that CBT clearly helps reduce depressive symptoms. The size of the benefit is smaller in the best-quality studies and after correcting for publication bias, so CBT probably helps but not quite as much as some older reviews suggested. They also found that CBT works about as well as other therapies and as well as antidepressant medication, and that combining CBT with medication helps more than medication alone. The review mostly looked at short-term results and the included studies varied a lot in quality and methods.

Key facts:

• The review combined about 115 studies of CBT for adult depression.
• Across roughly 75 studies that compared CBT to control groups, CBT reduced symptoms with an average effect that was originally measured as g = 0.71. That level of improvement roughly equals a number needed to treat of about 3 people.
• When the authors adjusted for likely publication bias (the tendency for positive studies to be published more), the average effect fell to g = 0.53, meaning the true benefit is probably smaller than the first number suggested.
• Higher-quality studies showed smaller benefits (about g = 0.53) than lower-quality studies (about g = 0.90), and this difference remained after accounting for other study features.
• The review found no clear evidence that CBT is more or less effective than other psychotherapies or than antidepressant medication.
• Combining CBT with medication was more effective than medication alone, with an improvement measured as g = 0.49.
• The authors noted important limitations: the studies differed a lot from each other, many were of low quality, and the review mostly examined short-term outcomes rather than long-term results.

Abstract

There is no doubt that CBT is an effective treatment for adult depression, although the effects may have been overestimated until now. CBT is also the most studied psychotherapy for depression, and thus has the greatest weight of evidence. However, other treatments approach its overall efficacy.

Topics

Anxiety, Depression, Psychometrics, Treatment, Cognitive Processes Digital Mental Health Interventions Mental Health Research Topics

Categories

Experimental and Cognitive Psychology Psychology Social Sciences

Tags

Clinical psychology Cochrane Library Cognition Cognitive behavioral therapy Cognitive therapy Depression (economics) Economics Internal medicine Law Macroeconomics Medicine MEDLINE Meta-analysis Pharmacotherapy Political science Psychiatry Psychology PsycINFO Publication bias Strictly standardized mean difference

Conditions & symptoms

Depression Lack of energy or motivation Sadness or low mood