AMP-C: A Digital Therapeutic for Reward Dysfunction in Co-Occurring Depression and Cannabis Use - PROJECT SUMMARY / ABSTRACT The comorbidity of cannabis use disorder (CUD) and major depressive disorder (MDD) is highly prevalent: 25% of cannabis users and 4.7% of persons with CUD meet criteria for MDD in their lifetime. Existing treatments for CUD and MDD often target one diagnosis at a time and not both concurrently. However, prior research indicates that integrative treatments, or those that target both disorders concurrently, yield better outcomes for co-occurring CUD/MDD. In addition, there are accessibility issues with receiving treatment for CUD and MDD due to time, financial, clinician availability, and stigma concerns. Digital therapeutics (DTx) may improve accessibility, but current DTx target CUD and MDD sequentially or have frequent clinician check-ins, limiting the impact and scalability of these DTx. Given that CUD and MDD both share deficits in reward processing for non-drug rewards, it is likely that a DTx targeting reward processing would address this urgent need for an integrated DTx for CUD and MDD. Dr. Collins has developed AMP-C, a DTx that targets the reward dysfunction in co-occurring CUD and MDD. AMP-C was created using the feedback of individuals with lived experiences of cannabis use and depressive symptoms to address the wants and needs of the users. In the proposed K23 project, Dr. Collins will conduct a pilot randomized controlled trial for AMP-C vs an active control group (i.e., symptom tracking) for individuals with co-occurring CUD/MDD (N = 80). The goals of the project are to evaluate the accessibility and feasibility of AMP-C (Aim 1), the preliminary efficacy of AMP-C compared to an active control group (Aim 2), and determine the impact of AMP-C on putative mechanisms of change, including passive sensing data (Aim 3). Participants will be randomized to AMP-C or the active control group, participate in the study over an 8-week period, and complete daily assessments on cannabis use, MDD symptoms, and positive affect, as well as intensively and objectively-collected passive sensing data. Participants will also complete assessments on cannabis use, MDD symptoms, and positive affect at baseline, post-intervention, and the follow-up assessments at 1 month, 3 months, 6 months, and 1 year. The proposed project is expected to yield important insight into both the understanding of the comorbidity of CUD and MDD over time and how a DTx targeting reward dysfunction may effectively treat these co-occurring disorders. To support her career development, Dr. Collins will work with an experienced mentorship team to receive training in clinical trial methodology for DTx, the development and maintenance of co-occurring disorders, intensive longitudinal methods, and mixed-methods research. The proposed project and training will provide a scalable, integrative DTx for CUD/MDD, prepare Dr. Collins for a career as an independent patient-oriented researcher for co-occurring disorders, and allow her to seek subsequent NIH R01 funding to further evaluate the efficacy of AMP-C in a larger, fully-powered, randomized controlled trial.
