Anxiety is commonly associated with insomnia. Given that social anxiety disorder is one of the most prevalent anxiety disorders, socially anxious individuals may be particularly vulnerable to insomnia. However, there is currently very little empirical work on this relationship. This study used bivariate correlations to examine whether social anxiety was related to insomnia in an undergraduate sample (n=176) using the Social Interaction Anxiety Scale and the Insomnia Severity Index. Further, we utilized responses from the Beck Depression Inventory to investigate the role of depressive symptoms in the association between social anxiety and insomnia. Hierarchical linear regressions were used to examine the moderational and mediational role of depressive symptoms in the link between social anxiety and insomnia. To increase generalizability to clinical samples, analyses were repeated on a subset of the sample with clinically significant social anxiety symptoms (n=23) compared to a matched control group (n=23). Consistent with expectation, social anxiety was associated with increased insomnia symptoms. Specifically, social anxiety was correlated with sleep dissatisfaction, sleep-related functional impairment, perception of a sleep problem to others, and distress about sleep problems. Importantly, depressive symptoms mediated the relationship between social anxiety and insomnia, thereby at least partially accounting for insomnia among socially anxious individuals. Our data support the contention that social anxiety is associated with insomnia and suggest that depression may play a vital role in this co-occurrence.
(c) 2007 Wiley-Liss, Inc.