This Letter presents the main findings of a systematic review of 21 studies (n = 33 398) on the psychosocial consequences of COVID-19 in children, adolescents, and young adults, following the PRISMA guidelines; the background, methods and results are presented as an online Supplement. According to our findings, excess worrying, irritability, home confinement, and fear of COVID-19 infection and transmission are associated with mild to severe anxiety symptoms during the COVID-19 epidemic. 1 Isolation could be a risk factor for deterioration in mental health, including depressive and anxiety symptoms, distress, fear, post-traumatic stress, and insomnia. 2 Regarding anxiety disorders, the fear of COVID-19, widely known as 'coronaphobia,' has enhanced anxiety symptoms, with a further aggravating role mediated by isolation at home. 2 Individuals with anxiety disorders tend to be preoccupied with excessive hand-washing, extreme cautiousness, social distancing measures and unnecessary shopping. 3 Furthermore, a strong correlation between family relations and fear of contracting COVID-19 was noted. 4 Focusing especially on COVID-19-infected patients, they were also affected, expressing high anxiety levels, as reported in SARS and MERS patients in the past. 5 states among school-age children with attention-deficit/hyperactive disorder during the COVID-19 outbreak.