RESUMEN
PURPOSE: Adolescent health surveillance systems are critical for understanding patterns of cannabis use; however, their limitations underscore the need for studies that generate new insights, particularly from individuals who are most impacted by negative outcomes. Our objectives were to learn about youths' cannabis use and their perceptions of their peers' cannabis use; their perspectives about trajectories of cannabis use over time and factors that influence trajectories; and perceived risks and benefits associated with cannabis use. METHODS: A group model building approach was used to gather data about cannabis use from a sample of urban, Black youth. Information about participants' cannabis use was assessed on eligibility screener, enrollment survey, and through structured activities over the course of four group model building workshops. RESULTS: Participants [(n = 20) mean age 18; 35% male and 95% Black] exclusively used the terms weed and blunts for cannabis. Youth who consume peers' blunts would not characterize themselves as cannabis users. Collectively, youth estimated the majority of Baltimore youth used cannabis by age 16 and that most used daily. Youth described cannabis as more beneficial than harmful. There were no gender differences in prevalence of use, but there were gender dynamics to shared use. DISCUSSION: Participatory research with urban, Black youth suggests youths' perceptions are misaligned with the ways that researchers conceptualize cannabis use. To better understand the scope of youth cannabis use and its harms, it is critical to leverage input from youth with lived experience to ensure survey tools adequately capture the way youth see themselves using cannabis.