ABSTRACT
OBJECTIVE/BACKGROUND: This pilot study aims to assess the effect of Cognitive Behavioral Therapy for insomnia (CBTi) in individuals with cannabis use disorder and insomnia. It also aims to investigate the effect of CBTi on levels of serum inflammatory markers in relation to insomnia symptoms. METHODS/PATIENTS: Individuals with cannabis use disorder and insomnia symptoms were recruited over 18 months. Data collected included demographics, self-reported sleep parameters, and cannabis use. Blood samples were drawn to measure IL-2, IL-6, CRP, and cortisol. Participants completed the Insomnia Severity Index questionnaire (ISI) and the Patient Health Questionnaire-4 (PHQ-4), and they were provided with an actigraphy (wrist) device for 1 week before CBTi and a subsequent week after completing the 4 CBTi sessions. RESULTS: Nineteen participants were enrolled in the study. The mean ISI score decreased from moderately severe insomnia at baseline to no clinically significant insomnia after CBTi with a sustained decrease at 3- and 6-months follow-up. Actigraphy showed a significant decrease in sleep onset latency (SOL) after CBTi. Three months after CBTi, 80% of participants reported a decrease in their cannabis use. There was also a significant and sustained decrease in mean PHQ-4 scores after CBTi. Although only trending towards significance, the levels of three out of four biomarkers (IL-2, IL-6, CRP) were decreased 6 months after CBTi. CONCLUSIONS: CBTi is effective as a short- and long-term treatment of insomnia and comorbid anxiety/depression in individuals who regularly use cannabis. A potential added benefit is a reduction in cannabis consumption and inflammatory serum biomarkers.