["Review of Development Economics, EarlyView. ", "\nABSTRACT\nWe report on the wellbeing of the young in twenty‐eight countries located in Eastern Europe and Central Asia including fifteen post‐Soviet countries. We find no evidence of the decline in the mental health of the young relative to older people, which characterizes Western Europe and English‐speaking advanced economies. The mental health of the young in ex‐Soviet republics is stable relative to older people across various surveys including the Gallup World Poll, the Eurobarometers, the World Values Surveys and the European Social Survey, as well as in surveys from the European Bank of Reconstruction and Development and UNICEF. However, there are three exceptions. A 2023 Flash Eurobarometer Mental Health survey conducted by the European Commission shows unhappiness declines in age in every EU member country including 11 in Eastern Europe. The same is found in the EU Commission's EU Loneliness Study of 2022 that was also internet based. An equivalent finding emerges in our analysis of the web‐based Global Minds surveys of 2020–2025 in several Central Asian republics. Young adults in these surveys are especially unhappy. Furthermore, in keeping with research on children aged 15–16 in the PISA surveys in other countries, we find life satisfaction of these school children in ex‐Soviet Republics declined over the period 2015–2022 and that, among this group, time spent on digital devices was associated with lower happiness.\n"]