Targeting cognitive-behaviour therapy to patients' implicit model of psoriasis: Results from a patient preference controlled trial

Objectives. The purpose of this study was to investigate the effects of a cognitive-behavioral psoriasis symptom management programme (PSMP) on patient-held perceptions about their condition and patients' use of self-reported coping strategies, and to examine the influence of alexithymia scores at induction on response to treatment. Design. Age- and sex-matched case-controlled prospective study. Methods. A total of 40 patients with psoriasis were treated in the PSMP, and an age-and sex-matched cohort received standard pharmacological care only. The Illness Perception Questionnaire was used to assess patients' beliefs about illness identity, time-line, consequences, cure/control and perceptions of the cause of their psoriasis. Participants also completed the COPE questionnaire and the Toronto Alexithymia Scale (TAS-20). Results. Results suggested that at 6-month follow-up, patients who chose the PSMP showed significant reductions in illness identity (the frequency and severity of symptoms that patients associate with their condition), the strength of belief in severity of consequences of their illness, and their attributions for emotional causes of their psoriasis. Perceptions about the anticipated course of the disease (time-line), its cure or controllability, ideas about physical agents of causation, and coping strategies did not differ between PSMP patients or controls at 6-week or 6-month follow-up. Alexithymia had no effect on response to treatment. Regression analyses demonstrated the importance of both participation in the PSMP and demographic/clinical history variables in accounting for significant variance in illness-perception-change scores. Conclusion. The findings are generally supportive of multivariate models of intervention, but the lack of a demonstrated effect of the intervention on coping may have implications for both the assessment of coping in psoriasis and the nature of psychological interventions proposed for its management.