Negative effects of psychotherapies for adult depression: A meta-analysis of deterioration rates.

Background: The risk for deterioration in patients receiving psychotherapy for adult depression has not been examined extensively and it is not clear whether psychotherapy reduces this risk or may even increase it in some patients. We conducted a meta-analysis of trials comparing these psychotherapies with control conditions that report deterioration rates.

Methods: We used an existing database of randomized trials on psychotherapies for adult depression which was updated up to 1/1/2017, through systematic searches in bibliographic databases. We included trials that reported clinically significant deterioration rates.

Results: We included 18 studies with 23 comparisons between therapy and control groups. The pooled risk ratio of deterioration was 0.39 (95% CI: 0.27∼0.57), indicating that patients in the psychotherapy groups have a 61% lower chance to deteriorate than patients in the control groups. We found that 20 patients need to be treated with psychotherapy in order to avoid one case of deterioration, compared to the control conditions. The median deterioration rate in the therapy groups was 4%, and in some studies more than 10%, indicating that clinicians should always be aware of the risk of deterioration.

Limitations: The results should be considered with caution because most studies had at least some risk of bias. Only 6% of all trials comparing psychotherapy with a control condition reported deterioration rates, using different ways to define deterioration which made pooling the prevalence rates across treatments and control groups impossible.

Conclusions: Psychological treatments of adult depression may reduce the risk for deterioration, compared to control groups, but this should be considered with caution because of the small proportion of studies reporting deterioration rates.