Dysfunctional sleep beliefs in Parkinson's disease: relationships with subjective and objective sleep

Disturbed sleep is common in Parkinson's disease and has a detrimental impact on functioning and quality of life. While the progression of the disease contributes to the aetiology of sleep problems in Parkinson's disease, it is unknown whether an individual's beliefs and attitudes about sleep play a role. In this study we sought to investigate whether dysfunctional beliefs and attitudes about sleep could be related to subjective and objective measures of sleep disturbance in Parkinson's disease. Ninety-three patients with Parkinson's disease completed the Dysfunctional Beliefs and Attitudes about Sleep 16 item questionnaire, which comprises four domains: Expectations, Worry/Helplessness, Consequences and Medication. Patients also completed the Pittsburgh Sleep Quality Index questionnaire and Beck Depression Inventory-II. Patients wore actigraphy watches and completed sleep diaries for 2 consecutive weeks, recording measures of sleep disturbance including Sleep Onset and Offset, Wake After Sleep Onset, Sleep Efficiency, and Wake Bouts per hour. Greater dysfunctional beliefs and attitudes in the domains of Worry/Helplessness and Medication were associated with lower perceived sleep quality and greater depressive symptoms. However, no relationships were found between dysfunctional beliefs and attitudes about sleep and any objective actigraphic measure of sleep disturbance. These findings suggest that beliefs and attitudes about sleep in Parkinson's disease are associated with mood disturbance, rather than objective measures of sleep. Thus it is possible that interventions targeting mood may lead to more accurate perceptions of sleep and improved quality of life in Parkinson's disease patients.