Despite lurid headlines suggesting a Tsunami of mental health conditions among children and young people (CYP) unleashed by the pandemic, our major problem is the lack of robust data. The McGill living systematic review screened approaching 50,000 abstracts by the end of April 2021, of which only 594 met the inclusion criteria; only 4 of the 79 with data extracted thus far relate to CYP, all from outside the United Kingdom (see https://www.depressd.ca/covid-19-mental-health). Prevalence estimates are extremely sensitive to sample selection, and measurement weighting can only partially address selection bias; however, large the sample and non-probability samples lack a theoretical basis for statistical inference.The mental health of CYP was deteriorating prior to COVID-19, while outcomes for those with poor mental health may be worse this century compared to earlier cohorts (Sellers et al., 2019). Only a quarter of those with a mental health condition were in contact with Child and Adolescent Mental Health Services (CAMHS) in the national survey of 2-to 19-year-olds in England conducted in 2017, which struggled with long waiting lists, despite rejecting 1 in 4 referrals (Crenna-Jennings & Hutchinson, 2020).So what do we know about the impact of the pandemic and the resulting restrictions in the United Kingdom? In the July 2020, the follow-up of the national survey was carried out. The number of 5-to 19-year-olds with a probable mental health condition increased from 1 in 9 to 1 in 6 (Vizard et al., 2020). The increase was seen in boys and girls, all age groups and all regions of the country, while young women remained at particularly high risk (1 in 4 vs. 1 in 8 17-to 19-year-old boys). In contrast, two repeated surveys of 13-to 14-year-olds conducted in October 2019 and April 2020 revealed no change in symptoms of anxiety, depression or well-being, but significant improvements among those scoring above clinical cut-off points in October (Widnall, Winstone, Mars, Haworth, & Kidger, 2020).Strong cross-sectional associations between poor parental mental health and poorer family functioning with probable mental health conditions are worrying, given parents with small children were particularly vulnerable to deteriorating mental health (Pierce et al., 2020), and poor parental mental health predicts subsequent emotional disorder in their children (Wilkinson et al., 2021).