Depression is a highly recurrent disorder. Rates of recurrence range between 35% and 85% over a time span of 15 years depending on nature of the sample. Psychotherapy is effective in depression in short or medium term. However some studies suggest that half of patients who responded to such therapies relapse in two years though CBT is found in some studies as providing more enduring effect.
Christiane Steinert and colleagues asked the question: In studies of sufficient follow-up ( i.e. more than two years), what is the overall likelihood for a depressive relapse post therapy?
The search was comprehensive and the PRISMA guidance were adhered to. All RCTs on Adult unipolar non psychotic depression where psychotherapy was compared against a non-psychotherapeutic comparison condition were included. From 2985 abstracts 60 were subjected to full review and 11 were included in the meta analysis.
Long-term follow-up data were available for 966 patients. Follow-up times varied between 34 and 72 months post-therapy, with an average of about 4.4 years. All patients in the comparison conditions received some form of active alternative treatment (pharmacotherapy or some form of psychotherapy ) that was designed not to contain ingredients that are specific for psychotherapy.
Pooled overall event rate ( observer rated relapse ) was 0.39 (95% CI 0.29, 0.50 ). Self-reported non-remission of the sample was 0.43 (95% CI 0.33, 0.53) i.e. about 40% of patients previously treated with psychotherapy had at least one relapse (or were still judged as depressed) by the end of the follow-up. Heterogeneity of results was large ( i.e. much of the observed difference between study results were due to non random differences between studies. i.e. quality, methodology, sampling etc ).
0.53 (95% CI 0.37, 0.68) of patients in the psychotherapy conditions and 0.71 (95% CI 0.58, 0.82) of patients in the non- psychotherapeutic comparison conditions had a relapse. Resulting NNT was 6 i.e. 6 patients had to be treated with psychotherapy to achieve one less relapse as compared to other treatments.
Limitations: Though most studies were graded as good quality, studies scored poorly on treatment integrity and therapist competence. All studies were originally designed as RCTs, but the follow-up of most of these trials has to be regarded naturalistic. Five studies only followed-up patients who were remitted after receiving different kinds of treatment in the first place.ie non-remitted patients were excluded from the follow-ups undermining the RCT’s core assumptions. Psychotherapy was delivered in different stages of a depressive disorder (remission, episode) and this limits comparability.
Conclusions: On average of 4.5 year follow-up, 40% of patients experienced a relapse post therapy. Psychotherapeutic interventions yielded a more favorable long-term outcome. Results has to be interpreted with caution given the limitations.
Summary of the article:
Relapse rates after psychotherapy for depression – stable long-term effects? A meta-analysis. Christiane Steinert , Mareike Hofmann , Johannes Kruse , Falk Leichsenring. 2014. Journal of Affective Disorders 168 (2014) 107–118. ( Online: July 2014)