An investigation into the interplay of substance use and prosocial tendencies on college students' psychological adjustment.

College students tend to engage in a variety of prosocial behaviors as well as substance use. Simultaneously, they are self-focused and capable of increased self-regulation. In the current study, we investigated the intersection of these behaviors on college students' self-development. Specifically, we hypothesized that substance use would relate curvilinearly to self-regulation and self-esteem, prosocial tendencies would relate positively to self-regulation and self-esteem, and prosocial tendencies would moderate the relations between substance use and the two self-variables. A total of 572 undergraduate students (72.2% women; =19.37 years, = 1.29) completed online surveys. As expected, a curvilinear relation between substance use and self-esteem was detected. In addition, results suggest that substance use negatively predicted self-regulation, whereas prosocial tendencies toward strangers and family positively predicted self-regulation. Prosocial tendencies as a moderator between substance use and the two self variables yielded mixed results. Therefore, the relation between substance use, prosocial tendencies, self-esteem, and self-regulation among college students remains nuanced and complex.