Each unhappy family is unhappy in its own way - a call for clearer conceptualization of adverse family factors in biosocial research on child and adolescent mental health problems.

Child and adolescent mental health problems stem from an interaction between biological and environmental factors. In the past decades, conceptualizations of genetic and neurobiological factors have become increasingly detailed. Development of our conceptualizations of environmental factors, in contrast, is lacking behind. Environmental adversity is usually conceptualized as one rather global factor, including, for example, both structural factors (e.g. poverty and racism) and psychosocial factors (e.g. parental violence or neglect). Or, as Chow et al. (2025) in this issue put it 'There is not yet a consensus on the best way to conceptualise adverse childhood experience'. In this Editorial, we call for clearer, more specific conceptualizations of family adversity in biosocial research. This development is essential for unravelling the mechanisms that shape child and adolescent mental health problems.