Problematic social media use is statistically predicted by using social media for coping motives and by positive reinforcement processes in individuals with high COVID-19-related stress levels.

It is important to understand the relationship between stress and problematic use of social media (PUSM). However, no study to our knowledge has yet investigated the longitudinal relationship between perceived stress and PUSM via positive and negative reinforcement processes. The present study investigated relationships between COVID-19-pandemic-related stress and PUSM and possible moderating effects of motives for using social media (positive and/or negative reinforcement) during and following a COVID-19-pandemic-related lockdown. Six-hundred-and-sixty participants initially completed a survey including self-report measures of PUSM, COVID-19-pandemic-related stress, and motives for using social media (i.e., for negative reinforcement involving coping and conformity or positive reinforcements involving enhancement and social motives). During the COVID-19 outbreak recovery period, 117 participants again completed the survey. Bayesian analyses revealed that PUSM was associated with higher COVID-19-pandemic-related stress levels and use of social media for coping, conformity, and enhancement purposes. Longitudinally, PUSM symptom worsening was associated with increased use of social media for coping motives regardless of levels of perceived stress. Use of social media for conformity and enhancement purposes moderated relationships between stress levels during lockdown and PUSM symptoms worsening after lockdown. Our findings corroborate the hypothesis that negative reinforcement processes may be key factors in PUSM symptom worsening regardless of perceived stress. Concurrently, high levels of stress may worsen PUSM through positive reinforcement processes.