Reward network properties in adolescents with cannabis use and depression

Evidence suggests that adolescent cannabis use results in long-lasting reward circuit alterations and heightened risk for future depression. Here, we examined whether reward network topology differs among adolescents with and without a history of cannabis use, independent of depression severity. Our ongoing research program focuses on adolescent depression, recruiting and evaluating youth from the New York City metropolitan area through clinician-based interviews and self-reported symptom measures. For this analysis, we included data from 71 participants (ages: 15.15 ± 2.05 years; 66% female) across a range of depressive severity as indexed by the Beck Depression Inventory (BDI). History of cannabis use was determined from interview reports and urine tests. fMRI was performed on a 3T Siemens Skyra. Preprocessing followed the Human Connectome Project (HCP) Pipelines. Resting-state data were parcellated via the Cole-Anticevic Brain-wide Network Partition, then subdivided into 3 reward networks based on a reward fMRI task. Weighted graph-theoretical metrics (Strength Centrality–CStr, Eigenvector Centrality–CEig, Local Efficiency–ELoc) were estimated within each network. Nonparametric group comparisons accounted for sex and familywise error rate (FWE). Adolescent cannabis users showed stronger Reward Prediction Error network CStr in the right cerebellum (pFWE < .05), which trended toward significance when adjusted for depression (pFWE = .0519). At a relaxed threshold (puncorrected < .005), cannabis use implicated Reward Prediction Error CStr in the left fusiform face complex and Reward Attainment CStr in the left nucleus accumbens and right dorsolateral prefrontal cortex, controlling for depression. No association was detected between cannabis use and Reward Anticipation CStr, or for CEig or ELoc in any network. Our results indicate differential resting-state network properties across reward nodes in adolescent cannabis users spanning a spectrum of depression symptomatology. These findings further implicate cannabis use in reward circuitry alterations among depressed youth. As our study is ongoing, future analyses will include data from additional participants.