R E S E A R C H A R T I C L E
Durability of treatment effects following internet-delivered
cognitive behavioural therapy for depression and anxiety
delivered within a routine care setting
Jorge E. Palacios
1,2
| Angel Enrique
1,2
| Olwyn Mooney
1
| Simon Farrell
1
|
Caroline Earley
1
| Daniel Duffy
1
| Nora Eilert
1,2
| Siobhan Harty
1
|
Ladislav Timulak
2
| Derek Richards
1,2
1
SilverCloud Science, SilverCloud Health, Dublin, Ireland
2
E-mental Health Research Group, School of Psychology, Aras an Phiarsaigh, Trinity College Dublin, Dublin, Ireland
Correspondence
Dr. Jorge E. Palacios, SilverCloud Science,
SilverCloud Health, One Stephen Street
Upper, Dublin Ireland.
Email:
jorge.palacios@tcd.ie;
jorge.palacios@silvercloudhealth.com
[Correction added on 21 May 2022, after first
online publication: IReL funding statement has
been added.]
Abstract
Objective: To investigate post-treatment relapse and remission rates 3, 6 and
9 months after completion of an acute phase of a clinician-supported internet-
delivered cognitive-behavioural therapy (iCBT) for anxiety and depressive symptoms,
within a routine care setting.
Method: Secondary analysis from a 12-month pragmatic randomized-controlled trial
delivered within the Improving Access to Psychological Therapies (IAPT) programme
in England. Participants in the intervention arm were included if they met criteria for
reliable recovery from depression (PHQ-9) and anxiety (GAD-7) at post-treatment
assessment. Survival analysis was used to assess durability of treatment effects and
determine predictors to relapse at 3-, 6- and 9-month follow-up. Hazard ratios
predicting time-to-relapse were estimated with semi-parametric Cox proportional
hazards model.
Results: Of the 241 participants in the intervention arm, 89 participants met the
criteria for reliable recovery from depression and anxiety at the post-treatment
assessment. Of these 89 eligible cases, 29.2% relapsed within the 9-month period,
with 70.8% remaining in remission at 9 months post-treatment. Of those who
relapsed, 53.8% experienced a relapse of depression and anxiety; 7.7% experienced a
relapse of depression only; and 38.4% experienced a relapse of anxiety only. Younger
age, having a long-term condition, and residual symptoms of anxiety at end-of-
treatment were all significant predictors of relapse.
Conclusions: This study is the first to explore the remission and relapse rates after an
acute phase of iCBT treatment, within a routine, stepped-care setting. The results
add to the scarce literature on the durability of the effects of iCBT treatment in
Received: 23 March 2021 Revised: 11 April 2022 Accepted: 12 April 2022
DOI: 10.1002/cpp.2743
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium,
provided the original work is properly cited.
© 2022 The Authors. Clinical Psychology & Psychotherapy published by John Wiley & Sons Ltd.
1768 Clin Psychol Psychother. 2022;29:1768–1777.
wileyonlinelibrary.com/journal/cpp
