Insomnia is a common condition. It is estimated that approximately 30% of the population experiences some symptom of insomnia, and approximately 5% to 15% of these individuals are likely to meet criteria for an insomnia disorder.1 Traditionally, insomnia was considered as either a primary disorder or secondary to another medical or psychiatric condition. During the past 2 decades, multiple lines of evidence have converged to support the proposition that insomnia, regardless of concurrent medical and/or psychiatric illness, is an independent disorder and should be treated accordingly.2 Partially in response, insomnia is now formally classified in the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) as a separate disorder, and the diagnosis of insomnia secondary to another condition was removed. Numerous studies have shown that targeted treatment for insomnia is effective in the context of other conditions. The success of cognitive behavioral therapy for insomnia (CBT-I) with secondary or comorbid insomnia strongly suggests that, although insomnia may be precipitated by psychiatric and/or medical illness, it is likely perpetuated by the same factors that are responsible for primary (chronic) insomnia.2 The application of CBT-I in patients with comorbid insomnia also had one significant and unexpected outcome: treatment gains were evident for the so-called parentdisorder. For example, CBT-I in patients with depression led to 29% lower depression ratings vs medication alone.3