Sleep attitudes impair sleep in seasonal affective disorder
medwireNews: Unhelpful beliefs about sleep, such as wishing for more sleep and worrying about the consequences of not getting enough sleep, are common in patients with seasonal affective disorder (SAD) and contribute to disturbed sleep, study findings suggest.
The study researchers therefore suggest that interventions to address these beliefs could help improve treatment response among patients with SAD.
Kathryn Roecklein (University of Pittsburgh, Pennsylvania, USA) and colleagues found that 51 patients with SAD had significantly higher scores on the Dysfunctional Beliefs and Attitudes about Sleep (DBAS-16) scale compared with 80 mentally healthy control individuals, at an average 4.43 versus 2.52.
Indeed, their average score was similar to that of 16 patients with major depressive disorder (MDD), at 4.46, and was higher than the clinically significant cut-off of 3.8.
A high percentage of SAD patients also had insomnia or hypersomnia, as measured on the Structured Interview Guide for the Hamilton Depression Rating Scale, Seasonal Affective Disorder Version (SIGH-SAD), with 47.1% reporting both.
These individuals had a high DBAS-16 score of 4.32 and while they had similar sleep duration, time in bed, and efficiency scores as those with insomnia or hyersomnia only, they had the highest Pittsburgh Sleep Quality Index score (7.11 vs 6.28 and 3.47, respectively). This group may therefore experience the poorest sleep quality, say the researchers.
They also report in Journal of Affective Disorders that self-reported insomnia accounted for the most variance in DBAS-16 total scores after adjusting for age, gender, and total SIGH-SAD score, and the magnitude accounted for by early insomnia was particularly large. Hypersomnia did not account for additional variance beyond that explained by insomnia.
"Given the rates of unhelpful beliefs about sleep in this SAD population, perhaps adjunctive [cognitive behavioral therapy] focused on sleep would improve treatment in SAD," Roecklein et al suggest.
They point out that the seasonal recurrence of SAD allows sleep-related cognitions to be measured during and between mood episodes, which "could help to determine if unhelpful sleep-related cognitions contribute to reports of sleep disturbance, and if so, may identify sleep disrupting beliefs as an important treatment target in SAD."
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Lucy Piper, Senior medwireNews Reporter