What types of insomnia relate to anxiety and depressive symptoms in late life?

Abstract

BackgroundSymptoms of insomnia are associated with symptoms of depression and anxiety in older adults, yet less is known about the relation of specific forms of insomnia (i.e., onset, maintenance, and terminal insomnia) with these symptoms. This study explored how insomnia types related to symptoms of anxiety and depression in older adults. It was hypothesized that onset and maintenance insomnia would have stronger relations to anxiety and depressive symptoms than terminal insomnia. MethodsOne-hundred thirty-three older adults (mean age 69, age range 65–89) were recruited using Amazon's Mechanical Turk. Participants completed the Insomnia Severity Index, Geriatric Depression Scale-Short Form, and Geriatric Anxiety Inventory-Short Form. ResultsRegression analyses that controlled for the comorbidity between anxiety and depressive symptoms indicated that onset insomnia was the only independent predictor of anxiety symptoms, and maintenance insomnia was the only independent predictor of depressive symptoms, each of which had medium to large effect sizes. LimitationsOur findings are limited by an online, primarily Caucasian, and non-clinical sample as well as the cross-sectional design of the study. ConclusionsOur findings suggest that despite overlap between symptoms of depression and anxiety, insomnia may have different mechanisms of affecting each disorder. Thus, the type of insomnia is clinically relevant and should be assessed when symptoms of anxiety, depression, and/or sleep difficulties are reported.