Association between Cannabis use, Depression and Apathy: A Study of an Internet Community Sample of Young Adults

The trait of amotivation is commonly clinically described among chronic cannabis abusers but few empirical studies have provided data on this dimension. Thus, our objective was to determine to what extent apathy, evaluated in a multidimensional approach, is associated with cannabis use and misuse in a community sample of young adults. 677 participants with a mean age of 20.5 years completed several web-formatted self-reports including the Lille Apathy Rating Scale (LARS) adapted to a self-report format (LARS-SR) and the 13-item Beck Depression Inventory (BDI-13). Participants were asked about their use of cannabis and, if appropriate, the Cannabis Abuse Screening Test (CAST) was completed. The problematic CU according to the CAST presented higher scores on the LARS-SR total score, LARS-SR subscales “intellectual curiosity”, “emotion”, and “action initiation” and he BDI-13 in comparison with non-problematic users. Regression analyses revealed that both apathy and depression were significant predictors of the CAST categories (non-symptomatic vs. moderate/severe). Despite some limitations, our study about the impairment of motivational functioning provides some new insight into the clinical implications of problematic patterns of cannabis use. Indeed, apathy was associated with both cannabis use and more severe patterns of cannabis use as evaluated with the CAST. The use of a scale investigating apathy as a multidimensional construct reveals that only some apathy dimensions seem involved in cannabis misuse independently of depression.