Breaking the cycle of intergenerational trauma: Evaluating the impact of parental adverse childhood experiences on parenting group outcomes using a mixed-methods approach

•Understanding Your Child’s Behaviour is acceptable with a diverse population.•Parent-based factors showed greater changes than child-based factors.•Qualitative methods of capturing childhood adversity are more sensitive and accurate.•Childhood adversity is nuanced, discrete and individual in its impact on parents engaged in interventions exploring their parenting practices.