Insomnia and generalized anxiety disorder: effects of cognitive behavior therapy for gad on insomnia symptoms

Although clinical practice suggests that sleep complaints are frequent among patients with generalized anxiety disorder (GAD), frequency, severity, types of insomnia complaints, and relationship to GAD diagnosis severity in patients diagnosed using Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria are not well documented. Clinical data about the impact on insomnia symptoms of treating GAD worries are also lacking. The present study examined these aspects in 44 GAD patients who participated in a treatment study specifically addressing excessive worries through CBT interventions. All patients were assessed using a structured clinical interview and the Anxiety Disorder Interview Schedule-IV (ADIS-IV). They also completed anxiety and insomnia inventories, including the Insomnia Severity Index (ISI), a self-report measure which assesses insomnia type, severity and interference with daily life. Among this sample, 47.7% reported difficulties initiating sleep, 63.6% reported difficulties maintaining sleep, and 56.8% complained of waking too early in the morning. The majority of these patients (86.5%) reported never having experienced insomnia without having excessive worries. However, insomnia severity and GAD severity were not correlated. In this sample, patients with severe GAD did not necessarily report more severe insomnia symptoms. Regarding treatment impact on insomnia complaints, ISI post-treatment scores were significantly lower after treatment. Mean post-treatment scores almost reached ISI's "absence of clinical insomnia" category. Results indicate that this CBT package for GAD does have a significant impact on sleep quality even if sleep disturbances were not specifically addressed during treatment.