This chapter reviews evidence regarding the connections between sleep and specific common psychiatric disorders, as well as potential treatment approaches. These associations are particularly relevant in older adults, given the high prevalence of both sleep and psychiatric disturbances that accompany aging. Patients who are taught the principles of cognitive behavioral therapy (CBT) may learn to apply them in the treatment of both anxiety disorders and insomnia. Both subjective sleep complaints and objective findings have been reported in elderly patients with anxiety and depressive disorders. A strong interplay exists between these underlying psychiatric disorders and sleep disturbances. Patients with depressive and anxiety disorders may complain of insomnia, while in turn insomnia may increase the risk of developing a psychiatric disorder. To address this interplay, treatment with either pharmacotherapy or psychotherapy may focus on both the sleep disturbances and mood or anxiety disorders to achieve optimal benefit.