From 2020 to 2023, the coronavirus-19 (COVID-19) pandemic exposed children to a variety of adverse childhood events, including parental loss, abuse, and disruption in services, and it exacerbated societal inequities. Studies evaluating the mental health of older children and adolescents reported increases in depression and anxiety symptoms, but no reviews have addressed the effects of the pandemic on preschool children. This systematic review and meta-analysis is the first to explore these effects. The goal was to analyze and synthesize longitudinal cohort studies to determine impact of the COVID-19 pandemic on the development and mental health of young children. Searches of multiple databases were performed for studies published between 2018 and 2023 with pre- and post-pandemic evaluations of the mental health or development of preschool children (aged 0–6 years) using objective measures and according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Cohen’s d effect sizes were calculated for each study that utilized the Strengths and Difficulties Questionnaire (SDQ), Ages and Stages Questionnaire (ASQ), or the Child Behavior Checklist (CBCL). Random-effects mixed models combined the estimates of effect sizes to calculate the overall mean effect size. The meta-analyses included 22,348 children from 16 countries. The analyses showed small increases in emotional symptoms and conduct problems, as well as increases in emotional reactivity, anxiety/depression, withdrawal symptoms, attention problems, and aggressive behaviors. A decrease in fine motor and personal–social skills was noted. Studies not included in these meta-analyses also showed negative effects on language and executive function. This systematic review characterizes the detrimental effects of the COVID-19 pandemic on the mental health and development of preschool children across the world. Our results suggest the vulnerability of early childhood to pandemic-related disruptions, although the heterogeneity in study design and child characteristics may limit some of these conclusions.

As of 2017, 1.8 million people living with HIV (PLWH) were adolescents between ages 10 and 19, accounting for 5% of all PLWH and 590,000 people between the ages 15 and 24 were newly infected with HIV. Between 2004 and 2011, AIDS-related deaths increased 50% among adolescents, and optimal adolescent adherence to antiretroviral treatment (ART) is estimated at only 62% of adolescents worldwide. While there have been great strides toward achieving the UNAIDS 90-90-90 goals, adolescents remain a group lacking appropriate resources and research to achieve these. This review analyzes current interventions aimed toward increasing adolescent ART adherence. Systematic searches of EMBASE, PubMed and PsycINFO were performed using the keywords ‘adolescent HIV medication adherence interventions’. The Gain Score effect size was calculated for studies reporting the Cohen's d and variance to include both prestudy and poststudy values. A random-effects model analyzed intervention significance. Authors were contacted to obtain additional data values and study clarification. Twelve studies met inclusion criteria for meta-analysis. There were no significant differences seen between control and intervention groups in medication adherence (z=−1.4714, p<0.1412), viral load (z=−0.1946, p<0.8547) or CD4+ lymphocyte count (z=0.2650, p<0.7910). There was no significant difference between studies in increasing medication adherence. Results indicate that interventions did not improve medication adherence in adolescents with HIV. However, the paucity of quantitative research available speaks to a need for more quantitative intervention studies and standardization of measures of intervention efficacy.