<p>The first comprehensive study to examine research on the mental health of children and young people using evidence from before and during COVID-19 discovered an effect on mental health that could lead to an increase in demand for support services. </p>.<p>This is the first research to examine research that has information on young people's mental health before and during the pandemic. </p>.<p>The study is published in the Journal of Child Psychology and Psychiatry. The study gives more insight into changes in the mental health of children and young people of various ages across the globe. </p>.<p>Researchers pulled together 51 studies that looked at how the pandemic affected young people's mental health across a range of domains. </p>.<p>Crucially, these studies included information on baseline mental health, collected before the pandemic rather than relying on retrospective perceptions of change. <br /> </p>