Psychological Medicine

Original Articles

Subclinical psychotic experiences and bipolar spectrum features in depression: association with outcome of psychotherapy

J. T. W. Wigmana1 c1, J. van Osa1a2, L. Abidia1, M. J. H. Huibersa3a4, J. Roelofsa3, A. Arntza3, I. Kellehera5 and F. P. M. L. Peetersa1

a1 Department of Psychiatry and Psychology, School of Mental Health and Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands

a2 King's College London, King's Health Partners, Department of Psychosis Studies, Institute of Psychiatry, London, UK

a3 Department of Clinical Psychological Science, Research Institute of Experimental Psychopathology, Faculty of Psychology and Neuroscience, Maastricht University, The Netherlands

a4 Department of Clinical Psychology, VU University, Amsterdam, The Netherlands

a5 Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Republic of Ireland

Abstract

Background Subthreshold psychotic and bipolar experiences are common in major depressive disorder (MDD). However, it is unknown if effectiveness of psychotherapy is altered in depressed patients who display such features compared with those without. The current paper aimed to investigate the impact of the co-presence of subclinical psychotic experiences and subclinical bipolar symptoms on the effectiveness of psychological treatment, alone or in combination with pharmacotherapy.

Method In a naturalistic study, patients with MDD (n = 116) received psychological treatment (cognitive behavioural therapy or interpersonal psychotherapy) alone or in combination with pharmacotherapy. Depression and functioning were assessed six times over 2 years. Lifetime psychotic experiences and bipolar symptoms were assessed at the second time point.

Results Subclinical psychotic experiences predicted more depression over time (β = 0.20, p < 0.002), non-remission [odds ratio (OR) 7.51, p < 0.016] and relapse (OR 3.85, p < 0.034). Subthreshold bipolar symptoms predicted relapse (OR 1.16, p < 0.037).

Conclusions In general, subclinical psychotic experiences have a negative impact on the course and outcome of psychotherapy in MDD. Effects of subclinical bipolar experiences were less prominent.

(Received October 23 2012)

(Revised March 20 2013)

(Accepted March 21 2013)

(Online publication May 07 2013)

Key words

  • Bipolar symptoms;
  • cognitive behavioural therapy;
  • interpersonal psychotherapy;
  • major depressive disorder;
  • psychotic experiences;
  • treatment outcome

Correspondence

c1 Address for correspondence: J. T. W. Wigman, Department of Psychiatry and Psychology, School of Mental Health and Neuroscience, Maastricht University Medical Centre, PO Box 616 (DRT 10), 6200 MD Maastricht, The Netherlands. (Email: hanneke.wigman@maastrichtuniversity.nl)

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