The roles of stress, coping, and parental support in adolescent psychological well-being in the context of COVID-19: A daily-diary study

•Adolescents’ health and financial stress predict same- and next-day negative affect.•Secondary control engagement coping predicted same- and next-day increases in positive affect.•Parental support predicted increases in same- and next-day positive affect.•Parental social support also reduced same-day negative affect.•Parental support and secondary control engagement coping buffer effects of stressors on affect. COVID-19 has introduced novel stressors into American adolescents’ lives. Studies have shown that adolescents adopt an array of coping mechanisms and social supports when contending with stress. It is unclear, though, which strategies are most effective in mitigating daily pandemic-related stress, as few micro-longitudinal studies have explored adolescents’ daily affect during COVID-19. Parental support may also be a critical component of adolescents’ pandemic-related coping, as adolescents’ peer networks have been limited by public health measures. This longitudinal study examined links between stress, coping, parental support, and affect across 14 consecutive days and 6216 assessments from a national sample of adolescents (N=444; Mage=15.0; 60% female; 44% Black/African American, 39% White/Europen American, 9% Latinx, 6% Asian American, 2% Native American) during school closures and state-mandated stay-at-home orders between April 8 and April 21, 2021. Adolescents’ health and financial stress predicted increases in same-day (health stress’ effect size = .16; financial stress’ effect size = .11) and next-day negative affect (health stress’ effect size = .05; financial stress’ effect size = .08). Adolescents’ secondary control engagement coping predicted increases in same-day (effect size = .10) and next-day (effect size = .04) positive affect and moderated the link between health stress and negative affect. Parental social support predicted increases in same-day (effect size = .26) and next-day (effect size = .06) positive affect and decreases in same-day (effect size = .17) negative affect and moderated the link between financial stress and negative affect. Results are indicative of conditions at the immediate onset of COVID-19 and should be interpreted as such. Findings provide information as to how health providers and parents can help adolescents mitigate the impact of COVID-19-related health and economic stressors on their psychological well-being. It remains critical to monitor the psychosocial impact of the pandemic on adolescents’ affect w