Cannabis use, heavy cannabis use, and cannabis-related problems are becoming increasingly common in the United States. Among those who use cannabis regularly, significant insomnia is common. For example, our data from 800 patients seeking medical cannabis indicate that insomnia is a chief comorbidity, with 80% of participants reporting that they regularly use cannabis to manage symptoms of insomnia. In addition, sleep problems are often a barrier to reducing cannabis use among those with Cannabis Use Disorders. Cognitive Behavioral Therapy for insomnia (CBTi) is highly effective in individuals with insomnia comorbid with other health conditions, including those with heavy and/or problematic use of substances; although it has not been fully tested in those with problematic cannabis use. In a recently-completed National Institute on Drug Abuse R34 randomized controlled pilot trial, our group found that, compared to a telemedicine-delivered Sleep Hygiene Education (SHE-TM) condition, a tailored telemedicine-delivered CBTi (CBTi-CB-TM) improved insomnia and daytime functioning and reduced cannabis use more during short-term follow-up among non- treatment-seeking adults using cannabis for sleep. In addition to important clinical questions related to the treatment of insomnia in those who use cannabis, the specific mechanisms linking heavy cannabis use and insomnia are poorly understood. We propose to evaluate whether a fundamental sleep regulatory system – homeostatic sleep drive – is dysregulated in subjects with problematic cannabis use and whether changes in this mechanism are associated with clinical outcomes. Thus, the aims of the proposed study are to recruit a sample of 200 adults with problematic cannabis use and insomnia to evaluate (1) the efficacy of CBTi-CB-TM vs. SHE-TM for sleep, cannabis use, and associated daytime symptoms and (2) the effects of CBTi-CB-TM on the homeostatic sleep system and its association with clinical outcomes. Building on the success of the recent R34, the proposed study will examine the longer-term outcomes associated with randomization to CBTi-CB-TM and utilize state-of-the-art measures of sleep homeostasis to examine the factors underlying the links between cannabis use, contents of the intervention, and objective sleep outcomes. These findings have important implications for understanding the relationship between cannabis use and sleep, as well as for identifying strategies to help improve outcomes in the large and growing group of individuals who report problematic cannabis use and sleep problems.