UCLA

Substance use rapidly increases during adolescence, particularly among youth who experience greater stress and negative emotion. However, limited research has examined whether responses to stress may predict adolescent substance use. Associations between adolescents’ responses to acute and daily responses to stress and substance use were tested. Adolescents in the CHAMACOS study completed a social-evaluative stress paradigm at age 14, in which they provided four samples of salivary cortisol, six emotion ratings, and electrocardiogram and impedance cardiogram consistently, and reported whether they had ever used any substances at ages 14 and 16. A community sample of adolescents also reported substance use and completed two weeks of daily reports of emotion and interpersonal conflict, up to three times for every two years, during the transition from adolescence to adulthood. Results indicated that blunted HPA axis responses to stress were related to use of alcohol by age 14, primarily driven by elevated cortisol at baseline, and vaping of nicotine by age 16 among adolescents above the poverty line. Also, female adolescents with blunted sadness reactivity to stress reported greater use of varied substances, and female adolescents with blunted happiness reactivity reported initiation of substances between ages 14 and 16 (Study 1). Blunted changes in sympathetic and parasympathetic nervous system activity, particularly profiles of coinhibition and reciprocal parasympathetic activation, were related to initiation of substance use among non-users (Study 2). Finally, blunted positive emotion reactivity was related to greater substance use among adolescents irrespective of gender, whereas greater anxious emotion reactivity among female adolescents and blunted depressive emotion reactivity among male adolescents were both related to greater substance use. These results consistently suggest that blunted responses to stress are related to greater substance use across psychological and physiological systems.