Background: Somatoform disorders are characterized by the presence of multiple somatic symptoms without an organic cause that completely explains their symptoms. These patients generate a high cost in health services. We aim to evaluate the effectiveness and feasibility of a cognitive-behaviour therapy (CBT) programme, administered in group and individual formats in primary care for patients who are diagnosed with abridged somatization disorder.
Design: Multicentre, randomized, controlled trial involving 3 groups, one of which is the control group consisting of standardized recommended treatment for somatization disorder in primary care (Smith's norms) and the 2 others, the intervention groups, consisting of cognitive-behavioural therapy (10 sessions) administered in individual format (intervention group 1) or in group format (intervention group 2).
Setting: 29 primary care health centres in the province of Zaragoza and 3 primary care health centres in the province of Mallorca, Spain.
Sample: N = 204 patients, (68 in each of the three groups), aged 18-65 years, able to understand and read Spanish, who fulfil Escobar's criteria of Abridgged Somatization Disorder (SSI 4,6), stable with pharmacotherapy over the previous month, and who will remain stable for the next 3 months in the doctor's opinion, having signed informed consent.
Control group: Standardized recommended treatment for somatization disorder in primary care (Smith's norms). INTERVENTION group: 10 weekly sessions of CBT, following a protocol designed by Prof. Escobar's group at UMDNJ, USA. There are 2 different treatment conditions: individual and group format.
Measurements: Survey on the use of health services, number and severity of somatic symptoms, anxiety, depression, quality of life and clinical global impression. The interviewers will not know which group the patient belongs to (blind). The assessments will be carried out at baseline, post-treatment, 6 months and 12 post-treatment.
Main variables: Utilization of health services, number and severity of somatic symptoms.
Analysis: The analysis will be per intent to treat. We will use the general linear models of the SPSS v.15 statistical package, to analyse the effect of treatment on the result variable (utilization of health services, number and severity of somatic symptoms).
Discussion: It is necessary to develop more effective psychological treatments for somatoform disorders. This randomised clinical trial will determine whether cognitive behaviour therapy, both in group or in individual format, is effective for the treatment of these patients.
Trial registration: Current controlled trials ISRCTN69944771.