Purpose of Review: To review the literature on the trends in substance use among youth during the coronavirus SARS-CoV-2 (COVID-19) pandemic. Recent Findings: The pandemic has given rise to concerns about the mental health and social well-being of youth, including its potential to increase or exacerbate substance use behaviors. This systematic review identified and included 49 studies of use across alcohol, cannabis, tobacco, e-cigarettes/vaping, and other drugs, and unspecified substances. The majority of studies across all categories of youth substance use reported reductions in prevalence, except in the case of other drugs and unspecified drug and substance use, which included three studies that reported an increase in use and three studies that reported decrease in use. Summary: Overall, the results of this review suggest that the prevalence of youth substance use has largely declined during the pandemic. Youth substance use in the post-pandemic years will require monitoring and continued surveillance.

Background: Differential effects of the coronavirus SARS‐CoV‐2 (COVID‐19) pandemic and associated public restrictions on adolescent girls and boys are emerging but have not been elucidated. This study examined gender differences across broad indicators of adolescent well‐being during the COVID‐19 pandemic in Iceland, and explored potential explanations for these differences. Methods: In total, 523 youth (56.5% girls) born in Iceland in 2004 completed measures on mental health problems (depressive symptoms, anger and suicide attempts) and measures designed for this study to assess broad indicators of adolescent well‐being (e.g., day‐to‐day life, academic performance, family and peer relationships, and mental and physical health) and behavioral changes during the COVID‐19 pandemic. Mental health problems during the pandemic were compared to expected scores based on nationwide ratings of same‐aged peers in 2018. Results: Although both boys and girls appeared affected, girls reported a greater negative impact across all the broad indicators of well‐being and behavioral change during COVID‐19 than boys, and their depressive symptoms were above and beyond the expected nationwide scores ( t (1514) = 4.80, p <  .001, Cohen's d = 0.315). Higher depressive symptoms were associated with increased passive social media use and decreased connecting with family members via telephone or social media among girls, and decreased sleeping and increased online gaming alone among boys. Concern about others contracting COVID‐19, changes in daily and school routines, and not seeing friends in person were among the primary contributors to poor mental health identified by youth, particularly girls. Conclusions: Adolescents were broadly negatively affected by the COVID‐19 pandemic and accompanying restrictions; however, this negative impact was more pronounced in girls. The findings suggest that a steady routine and remaining socially connected may help youth cope with the uncertainty and social restrictions associated with a pandemic. Moreover, healthcare providers, teachers, and other professionals should pay close attention to depressive symptoms among girls during a pandemic.

Adolescent substance use—the consumption of alcohol, tobacco, and other harmful drugs—remains a persistent global problem and has presented ongoing challenges for public health authorities and society. In response to the high rates of adolescent substance use during the 1990s, Iceland has pioneered in the development of the Icelandic Model for Primary Prevention of Substance Use—a theory-based approach that has demonstrated effectiveness in reducing substance use in Iceland over the past 20 years. In an effort to document our approach and inform potentially replicable practice-based processes for implementation in other country settings, we outline in a two-part series of articles the background and theory, guiding principles of the approach, and the core steps used in the successful implementation of the model. In this article, we describe the background context, theoretical orientation, and development of the approach and briefly review published evaluation findings. In addition, we present the five guiding principles that underlie the Icelandic Prevention Model’s approach to adolescent substance use prevention and discuss the accumulated evidence that supports effectiveness of the model. In a subsequent Part 2 article, we will identify and describe key processes and the 10 core steps of effective practice-based implementation of the model.