Impact of the Covid pandemic on the mental health of children and young people with pre-existing mental health and neurodevelopmental conditions: a systematic review and meta-analy... oleh B. C. F. Ching, V. Parlatini, S. Zhang, H. Abdul Cader, J. Penhallow, E. Voraite, T. Popnikolova, A. Wickersham, J. Downs, E. Simonoff