Aims There is growing concern about the mental health and well-being of children and young people (CYP) in the UK, with increasing demand for counselling services, admissions for selfharm and referrals to child and adolescent mental health services (CAMHS). We investigated whether there have been similar trends in selected mental and physical health outcomes among CYP in national health surveys from England, Scotland and Wales.

Methods Data on 1 40 830 participants (4–24 years) were analysed from the Health Survey for England (18 surveys 1995 – 2014; N=92 422), Scottish Health Survey (8 surveys 2003–14; n=16 862), and Welsh Health Survey (8 surveys 2007–2014; n=31 546). Seven outcome indicators were studied: WarwickEdinburgh Mental Wellbeing Score (WEMWBS); above-threshold Strengths and Difficulties Questionnaire Total (SDQT) score, SDQ Emotion (SDQE) score, General Health Questionnaire (GHQ) score; and self/parent reported variables: general health, any long-standing health condition, long-standing mental health condition. Regression models were used to investigate time trends in each variable.

Results Across all participants aged 4–24, prevalence of a selfreported mental health condition increased six-fold over the 19 year period in England (from 0.8% to 4.8%, p<0.001), more than doubled in Scotland over 11 years (2.3 to. 6.0%, p<0.001) and increased by more than half in Wales over 7 years (2.6% to 4.1%, p<0.001). In England, prevalence of any long-standing health condition and fair/poor self-reported health decreased over the same period (both p<0.001). Among young children (4–12y), the proportion reporting high SDQT and SDQE scores decreased significantly among both boys and girls in England (SDQE: OR=0.97(0.96–0.98), p<0.001) and girls in Scotland (SDQE: OR=0.96(0.93–0.99), p=0.005). The proportion with high SDQE scores (13–15y) decreased in England (OR=0.98 (0.96–0.99), p=0.006) but increased in Wales (OR=1.07(1.03–1.10), p<0.001). The proportion with high GHQ scores decreased among English women (16–24y) (OR 0.98(0.98–0.99), p=0.002). WEMWBS scores were unchanged.

Conclusions There has been a striking increase in the selfreported prevalence of long-standing mental health conditions among CYP in England, Scotland and Wales in recent years, although this was not always reflected in change in scores on validated questionnaires. These findings reinforce the need to consider what constitutes a mental health problem for young people and ensure that appropriate resources and services are available to support them and their families.