Open Access Highly Accessed Study protocol

Treatment of chronically depressed patients: A multisite randomized controlled trial testing the effectiveness of 'Cognitive Behavioral Analysis System of Psychotherapy' (CBASP) for chronic depressions versus usual secondary care

Jenneke E Wiersma1*, Digna JF van Schaik1, Patricia van Oppen1, James P McCullough2, Robert A Schoevers3, Jack J Dekker3, Marc BJ Blom4, Kristel Maas4, Johannes H Smit1, Brenda WJH Penninx1 and Aartjan TF Beekman1

Author Affiliations

1 Department of Psychiatry and Institute for Research in Extramural Medicine, VU University Medical Center and Academic Outpatient Clinic for Affective Disorders, Stichting GGZBuitenamstel-de Geestgronden, Amsterdam, The Netherlands

2 Department of Psychology, Virginia Commonwealth University, Richmond, USA

3 Department of Psychiatry, Mentrum, Amsterdam, The Netherlands

4 Department of Psychiatry, PsyQ, The Hague, The Netherlands

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BMC Psychiatry 2008, 8:18  doi:10.1186/1471-244X-8-18

Published: 25 March 2008



'Cognitive Behavioral Analysis System of Psychotherapy' (CBASP) is a form of psychotherapy specifically developed for patients with chronic depression. In a study in the U.S., remarkable favorable effects of CBASP have been demonstrated. However, no other studies have as yet replicated these findings and CBASP has not been tested outside the United States. This protocol describes a randomized controlled trial on the effectiveness of CBASP in the Netherlands.


The purpose of the present paper is to report the study protocol of a multisite randomized controlled trial testing the effectiveness of 'Cognitive Behavioral Analysis System of Psychotherapy' (CBASP) for chronic depression in the Netherlands. In this study, CBASP in combination with medication, will be tested versus usual secondary care in combination with medication. The aim is to recruit 160 patients from three mental health care organizations. Depressive symptoms will be assessed at baseline, after 8 weeks, 16 weeks, 32 weeks and 52 weeks, using the 28-item Inventory for Depressive Symptomatology (IDS). Effect modification by co morbid anxiety, alcohol consumption, general and social functioning and working alliance will be tested. GEE analyses of covariance, controlling for baseline value and center will be used to estimate the overall treatment effectiveness (difference in IDS score) at post-treatment and follow up. The primary analysis will be by 'intention to treat' using double sided tests. An economic analysis will compare the two groups in terms of mean costs and cost-effectiveness from a societal perspective.


The study will provide an answer to the question whether the favorable effects of CBASP can be replicated outside the US.

Trial Registration

The Dutch Cochrane Center, NTR1090.