An Examination of Relationships Between Mental Health Symptoms, Marijuana Use Motives, and Marijuana Use Outcomes Among Late Adolescents in Washington State
Authors: Wallace Elliot , Chu Li-Hui , Ramirez Jason 
Published: April 2021

Adolescence is a critical period of development which can be affected by the initiation and escalation of marijuana use. Examining risk factors of marijuana misuse among adolescents is a public health priority. Previous research examining depression and anxiety as risk factors for marijuana use among young adults is mixed. Some studies found a positive relationship between mental health symptoms and marijuana use, while other studies have found gender-specific relationships or no relationship at all. Despite this research, little is known regarding mental health symptoms and marijuana use among adolescents. The aims of current analysis were to 1) examine associations between mental health symptoms and marijuana use behavior among adolescents, and 2) examine coping motives as a moderator of the relationship between mental health symptoms and marijuana outcomes. The current study included 170 late adolescents (15-18 years old, Mage = 16.86, SDage = 0.94, 50% female) recruited from Washington State. The sample was stratified by gender and marijuana use such that participants ranged from never using marijuana to reporting heavy, regular marijuana use. Participants were asked to complete three online assessments over the course of six months. Data described here come from the first online assessment. This included a 4-item measure of mental health symptoms (depression and anxiety) in the past 2 weeks, in addition to measures of marijuana use, marijuana-related consequences, and marijuana use motives. A series of initial linear regression models that controlled for age and sex found that mental health symptoms were not significantly associated with typical marijuana use (p > .05) but were significantly positively associated with marijuana-related consequences (β = 0.33, p < .001). Additional models that also included coping motives found that stronger endorsement of using marijuana to cope with negative affect was associated with more hours high in a typical week (β = 0.25, p < .05) and more marijuana-related consequences (β = 0.24, p < .05). There were no significant interactions between coping motives and mental health symptoms in predicting either marijuana use or consequences (ps > .05). The findings suggest that adolescents who report more mental health symptoms do not necessarily use more marijuana than those who report fewer symptoms, but may be at greater risk for experiencing negative consequences as a result of their usage. Additionally, the results suggest a stronger endorsement of using marijuana to cope with negative affect is related to greater marijuana use and risk for experiencing negative consequences. No evidence of moderation was found suggesting the relationships between mental health symptoms and marijuana use outcomes do not vary as a function of coping motives. Screening during adolescence for early signs of mental health symptoms to predict risk may be beneficial towards preventing negative outcomes and providing early interventions for marijuana misuse.