Investigating the relationship between adolescent mental health and wellbeing in a nationally representative survey of 11-16 year olds in Wales

BackgroundImproving mental health (MH) and wellbeing (WB) of children is a national priority, yet there is no consensus on how these constructs are defined, nor the relationship between them. This is essential to ensure action is directed to where it has the greatest potential to prevent poorer MH and WB. MethodsThe School Health Research Network includes 191,975 pupils from 196 secondary schools in Wales (94% coverage of all schools). Annual pupil health survey data was used to investigate the relationship between MH (Strengths and Difficulties Questionnaire Total Difficulties (SDQTD)) and WB (Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS)) in a multilevel modelling framework. The primary sample size comprised any 11-to 16-year-old pupils with a pair of SWEMWBS and SDQTD scores in the 2019 or 2021 survey (N=191,975). Adjustment was made for variables hypothesised to influence MH or WB, grouped into demographic, behavioural, social, and structural domains. FindingsWorsening SDQTD categories predicted lower SWEMWBS scores in a clinically significant dose-response relationship in the fully adjusted model, ranging from slightly raised SDQTD (b = -1.68, 95% CI = -1.76, -1.61), high SDQTD (b = -2.41, 95% CI = -2.51, -2.31), and very high SDQTD (b = -3.63, 95% CI = -3.71, -3.55). Sensitivity analysis including pupils with missing SDQTD scores showed a similar pattern of results. ConclusionThese findings indicate a strong negative association between MH difficulties and WB among pupils in Wales. Determining whether treatment and prevention techniques for poor MH are shared or distinct could help allocate resources and efforts efficiently.