The Role of Positive and Negative Affect in Illicit Substance Use and Alcohol Use: An Ecological Momentary Assessment Study

Objective: Theories suggest that experiences of negative and positive affect are important precursors to alcohol and illicit subhas generally supported the relation between momentary experiences of positive affect, but not negative affect, and subsequent substance use. Unfortunately, most of these studies have focused on alcohol use and not other substance use. The goal of this study was to further explore the relation between momentary affect and the use of both alcohol and illicit substances within a population of individuals with a history of substance use. In addition, this study aimed to understand whether the relations between affect and substance use would vary depending on the timing of EMAs of affect before substance use. Method: Participants with a history of heavy substance use (N = 59) completed EMAs measuring affect and substance use using random prompts 4 times a day for 14 days. Results: We found that positive affect was significantly related to later engagement in drinking, illicit substance use, and marijuana use. Moreover, timing of the affect was important. When affect was assessed in the last hour before substance use, relative to 7 hours earlier, the relation between positive affect and illicit substance use was stronger. Negative affect was related to a lower likelihood of subsequent marijuana use, but more so when it was measured a few hours versus several hours before the use. Conclusions: This study further supported the relation between positive affect and both alcohol and illicit substance use.