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

Sanne J E Bruijniks*, Lotte H.J.M. Lemmens, Steven D Hollon, Frenk P.M.L. Peeters, Pim Cuijpers, Arnoud Arntz, Pieter Dingemanse, Linda Willems, Patricia van Oppen, Jos W R Twisk, Michael van den Boogaard, Jan Spijker, Judith Bosmans, Marcus J.H. Huibers

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


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.

Original languageEnglish
Pages (from-to)222-230
Number of pages9
JournalBritish Journal of Psychiatry
Issue number4
Early online date7 Feb 2020
Publication statusPublished - Apr 2020


  • Depressive disorders
  • cognitive-behavioural therapies
  • individual psychotherapy
  • out-patient treatment
  • randomised controlled trial

Cite this

Bruijniks, S. J. E., Lemmens, L. H. J. M., Hollon, S. D., Peeters, F. P. M. L., Cuijpers, P., Arntz, A., Dingemanse, P., Willems, L., van Oppen, P., Twisk, J. W. R., van den Boogaard, M., Spijker, J., Bosmans, J., & Huibers, M. J. H. (2020). The effects of once- versus twice-weekly sessions on psychotherapy outcomes in depressed patients. British Journal of Psychiatry, 216(4), 222-230.