Research Review: The impact of the COVID-19 pandemic on the mental health of children and young people with pre-existing mental health and neurodevelopmental conditions - a systematic review and meta-analysis of longitudinal studies.

Abstract

Background: Systematic reviews have suggested mixed effects of the COVID-19 pandemic on the mental health of children and young people. However, most included studies focused on the general population and were cross-sectional. The long-term impact on those with pre-existing mental health and/or neurodevelopmental conditions remains unclear. Thus, we conducted a systematic review and meta-analysis to examine the longitudinal impact of the pandemic on the mental health of this clinical population and potential explanatory factors.

Methods: Ovid Medline, Embase, APA PsycInfo and Global Health databases were searched between 1 January 2020 and 3 August 2023 (PROSPERO CRD42022383546). We included longitudinal studies that compared mental health symptoms between pre- and during pandemic and/or during pandemic timepoints in children and young people (≤18 years old) with pre-existing mental and/or neurodevelopmental conditions. Outcomes included internalising, externalising and other symptoms. Risk of bias was rated using an adapted tool. Included studies were narratively synthesised and multi-level meta-analyses were conducted where the number of studies was sufficient.

Results: We identified 21 studies (N = 2,617) from 6,083 records. Studies differed across countries, diagnoses, measures, informants and timepoints. All had overall moderate-to-high risk of bias. Narrative synthesis found mixed evidence of symptom change, with individual studies showing increase/reduction/no change. Factors such as diagnosis, baseline symptom severity, age and sex/gender may explain variation in outcomes. Multi-level meta-analyses were feasible for a limited number of outcomes and found no significant changes in internalising and externalising symptoms pre- versus during pandemic or internalising symptoms between 2020 pandemic phases, and high heterogeneity was noted.

Conclusions: The impact of the pandemic on the mental health of children and young people with pre-existing conditions varied according to individual and contextual vulnerabilities, which were not fully captured in pooled analyses. Further research needs to investigate longer-term impacts and better stratify this vulnerable population.