Psychological Medicine

  • Psychological Medicine / Volume 45 / Issue 11 / August 2015, pp 2365-2373
  • Copyright © Cambridge University Press 2015 This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (, which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
  • DOI: (About DOI), Published online: 25 March 2015

Original Articles

Psychological treatments for early psychosis can be beneficial or harmful, depending on the therapeutic alliance: an instrumental variable analysis

L. P. Goldsmitha1, S. W. Lewisa2, G. Dunna2 and R. P. Bentalla3 c1

a1 University of Manchester, Manchester, UK

a2 Institute of Brain Behaviour and Mental Health, Institute of Population Health, University of Manchester; Manchester Mental Health and Social Care Trust, Manchester, UK

a3 Department of Psychological Sciences, Liverpool University, Liverpool, UK


Background The quality of the therapeutic alliance (TA) has been invoked to explain the equal effectiveness of different psychotherapies, but prior research is correlational, and does not address the possibility that individuals who form good alliances may have good outcomes without therapy.

Method We evaluated the causal effect of TA using instrumental variable (structural equation) modelling on data from a three-arm, randomized controlled trial of 308 people in an acute first or second episode of a non-affective psychosis. The trial compared cognitive behavioural therapy (CBT) over 6 weeks plus routine care (RC) v. supportive counselling (SC) plus RC v. RC alone. We examined the effect of TA, as measured by the client-rated CALPAS, on the primary trial 18-month outcome of symptom severity (PANSS), which was assessed blind to treatment allocation.

Results Both adjunctive CBT and SC improved 18-month outcomes, compared to RC. We showed that, for both psychological treatments, improving TA improves symptomatic outcome. With a good TA, attending more sessions causes a significantly better outcome on PANSS total score [effect size −2.91, 95% confidence interval (CI) −0.90 to −4.91]. With a poor TA, attending more sessions is detrimental (effect size +7.74, 95% CI +1.03 to +14.45).

Conclusions This is the first ever demonstration that TA has a causal effect on symptomatic outcome of a psychological treatment, and that poor TA is actively detrimental. These effects may extend to other therapeutic modalities and disorders.

(Received January 23 2014)

(Revised November 03 2015)

(Accepted February 02 2015)

(Online publication March 25 2015)

Key words

  • Cognitive therapy;
  • counselling;
  • first episode;
  • psychosis;
  • therapeutic alliance


c1 Address for correspondence: R. P. Bentall, Department of Psychological Sciences, Liverpool University, Liverpool L69 3GL, UK. (Email: