The effects of once- versus twice-weekly sessions on psychotherapy outcomes in depressed patients

Br J Psychiatry. 2020 Apr;216(4):222-230. doi: 10.1192/bjp.2019.265.


Background: It is unclear what session frequency is most effective in cognitive-behavioural therapy (CBT) and interpersonal psychotherapy (IPT) for depression.

Aims: Compare the effects of once weekly and twice weekly sessions of CBT and IPT for depression.

Method: We conducted a multicentre randomised trial from November 2014 through December 2017. We recruited 200 adults with depression across nine specialised mental health centres in the Netherlands. This study used a 2 × 2 factorial design, randomising patients to once or twice weekly sessions of CBT or IPT over 16-24 weeks, up to a maximum of 20 sessions. Main outcome measures were depression severity, measured with the Beck Depression Inventory-II at baseline, before session 1, and 2 weeks, 1, 2, 3, 4, 5 and 6 months after start of the intervention. Intention-to-treat analyses were conducted.

Results: Compared with patients who received weekly sessions, patients who received twice weekly sessions showed a statistically significant decrease in depressive symptoms (estimated mean difference between weekly and twice weekly sessions at month 6: 3.85 points, difference in effect size d = 0.55), lower attrition rates (n = 16 compared with n = 32) and an increased rate of response (hazard ratio 1.48, 95% CI 1.00-2.18).

Conclusions: In clinical practice settings, delivery of twice weekly sessions of CBT and IPT for depression is a way to improve depression treatment outcomes.

Keywords: Depressive disorders; cognitive–behavioural therapies; individual psychotherapy; out-patient treatment; randomised controlled trial.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cognitive Behavioral Therapy* / methods
  • Depressive Disorder / therapy*
  • Depressive Disorder, Major / therapy
  • Female
  • Follow-Up Studies
  • Humans
  • Interpersonal Psychotherapy* / methods
  • Male
  • Middle Aged
  • Outcome Assessment, Health Care*
  • Outcome and Process Assessment, Health Care*
  • Outpatients
  • Time Factors