The role of illness beliefs in disrupted sleep in people with psoriasis

Abstract

Background Psoriasis is a common immune-mediated skin condition associated with significant psychological and medical comorbidity. Research by our group has shown that sleep problems are common in psoriasis and associated with itch, low mood and pre-sleep cognitive arousal. Illness beliefs relate to how an individual perceives health threats, and are important predictors of psychological outcomes in psoriasis. Given that sleep problems are associated with cognitive factors, and that illness beliefs play a role in determining health outcomes, we sought to investigate the association between illness and treatment beliefs (about psoriasis) and sleep. Methods 186 respondents (75.3% female, mean age = 39.2) with psoriasis from 14 countries completed an online survey assessing sleep (Pittsburgh Sleep Quality Index), psoriasis (Simplified Psoriasis Index) and illness beliefs (Brief Illness Perceptions Questionnaire). Group comparisons compared good and poor sleepers on illness beliefs. Correlations and regression analyses explored the role of illness beliefs in sleep. Results The mean PSQI was 9.24 (SD=4.32), with 76.3% classified as poor sleepers (PSQI>5). Whilst consequences, identity, concern and emotional representations independently predicted sleep quality, consequences was the strongest predictor (β=.455;p<.001). When controlling for all significantly correlated beliefs, consequences emerged as the only significant predictor (β=.284;p=.006), explaining 23.4% of variance. Discussion Illness and treatment beliefs about psoriasis are associated with poor sleep, and beliefs about the consequences of psoriasis had the biggest influence on sleep in this sample. Targeting people’s beliefs about their psoriasis should be explored as a potential intervention for improving sleep and other outcomes in this population.