Cannabis and self-regulation

Abstract

Cannabis is one of the most used recreational substances, especially among adolescents and young adults. Two studies examined the relationship between cannabis use and self-regulation among undergraduates. The first study (N = 248), an online survey, found that cannabis, alcohol, and cigarette use were related to lower levels of self-regulation. Among these substances, multiple regression analyses showed that cannabis use uniquely predicted lower levels of self-control and executive functioning when controlling for impression management. The second study (N = 31) compared regular cannabis users (n = 11) to nonusers (n = 15) on self-regulation performance following an ego depletion task. The depletion manipulation task required participants to choose between many everyday products, recreational substances, and occupations. To ensure the depletion task was effective, depleted nonusers (n = 15) were compared to a control group of nonusers (n = 5). The ego depletion manipulation was unsuccessful. Cannabis users did, however, perform worse on the Stroop task and a handgrip endurance task. Additionally, reported self-control from study one did not predict performance on these tasks at study two when controlling for cannabis use. The findings demonstrate that cannabis use is uniquely linked to lower levels of self-control, however, the causal order of this relationship remains unclear. The failure to replicate the ego depletion effect is discussed.