Insomnia, characterized by an inability to initiate and maintain sleep, is a defining feature of mood disorders such as depression. CBT has been found to be an effective treatment for depression-related insomnia. This study will determine the effectiveness of CBT in treating insomnia that is secondary to depression. In addition, this study will assess the relationship between insomnia and depression, since previous studies have shown that insomnia may not only be a symptom of depression but may also indicate the onset of a depressive episode.~Participants will be randomly assigned to receive weekly sessions of either CBT or clinician monitoring for 8 weeks. Participants in both groups will meet with a therapist at selected visits, but only CBT participants will receive actual therapy. All participants will have 13 study visits; four will be overnight visits in a sleep lab. On Visit 1, participants will complete questionnaires about their sleep quality and symptoms of depression. Participants will also undergo a physical exam and will begin a daily sleep diary. Visits 2, 3, 12, and 13 will be overnight visits in the sleep lab. During these visits, participants will have electrodes placed on their bodies and a polysomnograph will be used to monitor their sleep. Participants will meet with their therapist on Visits 4 to 11. Participants' sleep diaries, depression scales, and sleep scales will be used for assessment. After the intervention part of the study is complete, participants will have monthly follow-up visits for up to 2 years. During the follow-up visits, participants will complete questionnaires about their sleep quality and symptoms of depression.
This study will determine the effectiveness of cognitive behavioral therapy (CBT) in treating insomnia symptoms that are secondary to depression. This study will also determine how long the benefits of CBT will last and how the recurrence of insomnia is associated with the onset of new depressive episodes.