Sleep disturbances are common among older adults with GAD, with 52–68% of adults with GAD in this study reporting moderate or severe insomnia and over 90% reporting dissatisfaction with sleep. The most frequently reported type of insomnia was sleep maintenance insomnia, followed by early morning awakening, and initial insomnia. This is consistent with Saletu et al.’s (6
) findings of polysomnographic evidence of increased wake times, increased early morning awakenings, and decreased total sleep among a wide age range of patients (24 to 65 years) with GAD. They suggested that one potential mechanism is that CNS hypervigilance and hyperarousal associated with GAD causes insomnia.
ISI scores were lowest among individuals with no diagnosis and highest among individuals with GAD diagnoses (with or without comorbid depression), with the worried well falling in the middle. ISI scores for participants with GAD were similar to those reported by Bastien and colleagues (18
) in a sample of older adults recruited for an RCT to treat insomnia (M = 15.4), and higher than the scores of young and middle aged adults recruited for an RCT to treat GAD (M = 11.5) (2
) . Thus, older adults with GAD report levels of sleep disturbances similar to those of older adults diagnosed with insomnia and higher than those of young and middle-aged adults with GAD. This suggests that the increased prevalence in sleep disturbances among nonclinical samples of older adults is present in participants with GAD as well.
Total sleep scores on the ISI distinguished the worried well from participants with GAD. This is consistent with Wetherell and colleagues (19
) who found that disturbed sleep was one of the strongest discriminators among normal, worried well, and GAD older adults in multivariate discriminant function analyses. Although a large percentage of worried well participants reported they were dissatisfied with their sleep (85%), only 16% had moderate or severe insomnia. Approximately 90% of participants with GAD also reported dissatisfaction with sleep; by contrast 52–68% met criteria for insomnia.
There were no significant differences between participants with GAD with and without comorbid depression on total sleep disturbance scores or on individual items. This suggests that the sleep of older GAD participants is impaired regardless of the presence of a comorbid depression diagnosis. It is not known if sleep disturbance within the context of GAD is a risk factor for depression.
These findings must be interpreted within the context of some limitations. First, the order of occurrence of sleep disturbances and anxiety symptoms are not known. Therefore, we cannot determine if sleep disturbances preceded GAD or vice versa. Second, we do not have objective measures of sleep (e.g., polysomnography) or sleep diaries.
Results of other studies suggest that insomnia within the context of GAD can be successfully treated, and this treatment can have an impact on anxiety severity. Belanger et al (2
) found that CBT for GAD produced significant declines in sleep disturbance even though concerns about sleep were not specifically targeted by the intervention. More recently, Pollack and colleagues (20
) evaluated the addition of eszopiclone to escitalopram for the treatment of sleep disturbance in adults with GAD. Participants who received eszopiclone and escitalopram demonstrated greater improvements in sleep disturbance than participants who received escitalopram and placebo. Further, participants who received both medications also demonstrated greater reduction in anxiety severity, faster response, and greater likelihood of remission. Thus, treatment of insomnia among people with GAD may result in greater and faster anxiolytic effects.
Given the high rates of sleep disturbance and dissatisfaction with sleep reported by adults with GAD, sleep disturbances should be routinely assessed and treated when warranted among older adults with GAD. Some have integrated sleep management skills into their GAD treatment protocol (21
) while others provide a sleep management module only to those with significant sleep disturbances (22
). Further research is needed to determine if improvements in sleep mediate the effects of treatment on anxiety severity.