Emotion regulation has been put forward as an important transdiagnostic process. However, previous analyses of the relationships between emotion regulation strategies and symptoms of psychopathology in children and adolescents have produced mixed results. The present meta-analysis examines the relationships between youth's habitual use of three adaptive (acceptance, problem-solving, and cognitive reappraisal) and three maladaptive (rumination, avoidance, and suppression) strategies with symptoms of depression, anxiety, aggression, and addiction. A total of 181 articles with 386 effect sizes were analyzed. Rumination, avoidance, and acceptance showed the largest effect sizes across all symptoms. Maladaptive strategies showed, in general, larger effect sizes than adaptive strategies. Effect sizes were generally larger for internalizing compared to externalizing symptoms. The findings underscore the importance of emotion regulation for mental health in youth. Public Health Significance StatementEmotion regulation strategies are significantly linked to symptoms of psychopathology in youth. Rumination, avoidance, and acceptance show the largest effects across symptoms. Emotion regulation strategies should be taught in school and clinical practice for prevention and treatment.

Trajectories of internalizing disorders and behavioral addictions are still largely unknown. Research shows that both disorders are highly comorbid. Previous longitudinal studies have focused on associations between internalizing disorders and behavioral addictions using screening instruments. Our aim was to develop and examine a theory-based model of trajectories, according to which internalizing disorders foster symptoms of Internet use disorders, mediated by a reward deprivation and maladaptive emotion regulation. We applied clinically relevant measures for depression and social anxiety in a prospective longitudinal study with a 12-month follow-up investigation. On the basis of an at-risk population of 476 students (mean age = 14.99 years, SD = 1.99), we investigated the predictive influence of clinically relevant depression and social anxiety at baseline (t1) on Internet use disorder symptoms at 12-month follow-up (t2) using multiple linear regression analyses. Our results showed that both clinically relevant depression and social anxiety significantly predicted symptom severity of Internet use disorders one year later after controlling for baseline symptoms of Internet use disorders, gender and age. These results remained robust after including both depression and social anxiety simultaneously in the model, indicating an independent influence of both predictors on Internet use disorder symptoms. The present study enhances knowledge going beyond a mere association between internalizing disorders and Internet use disorders. To our knowledge, this is the first study investigating clinically relevant depression and social anxiety to predict future Internet use disorder symptoms at 12-month follow-up. In line with our model of trajectories, a significant temporal relationship between clinically relevant internalizing disorders and Internet use disorder symptoms at 12-month follow-up was confirmed. Further studies should investigate the mediating role of reward deprivation and maladaptive emotion regulation, as postulated in our model. One implication of these findings is that clinicians should pay particular attention to the increased risk of developing behavioral addictions for adolescents with depression and social anxiety.