Accumulating evidence shows that an increasing number of children and young people (CYP) are reporting mental health problems.

To investigate emotional disorders (anxiety or depression) among CYP in England between 2004 and 2017, and to identify which disorders and demographic groups have experienced the greatest increase.

Repeated cross-sectional, face-to-face study using data from the Mental Health of Children and Young People surveys conducted in 2004 and 2017, allowing use of nationally representative probability samples of CYP aged 5–16 years in England. A total of 13 561 CYP were included across both survey waves (6898 in 2004 and 6663 in 2017). We assessed the prevalence of any emotional, anxiety and depressive disorder assessed using the Development and Well-Being Assessment and classified according to ICD-10 criteria.

The prevalence of emotional disorders increased from 3.9% in 2004 to 6.0% in 2017, a relative increase of 63% (relative ratio 1.63, 95% CI 1.38, 1.91). This was largely driven by anxiety disorders, which increased from 3.5 to 5.4% (relative ratio 1.63, 95% CI 1.37, 1.93). The largest relative changes were for panic disorder, separation anxiety, social phobia and post-traumatic stress disorder. Changes were similar for different genders and socioeconomic groups, but differed by ethnicity: the most pronounced increase was among White CYP (relative ratio 1.88, 95% CI 1.59, 2.24), compared with no clear change for Black and minority ethnic CYP (relative ratio 0.85, 95% CI 0.52, 1.39). Comorbid psychiatric conditions were present in over a third of CYP with emotional disorders, with the most common being conduct disorder.

Between 2004 and 2017, the increase in emotional disorders among CYP in England was largely driven by anxiety disorders. Socioeconomic inequalities did not narrow. Disaggregating by ethnicity, change was evident only in White CYP, suggesting differential trends in either risk exposure, resilience or reporting by ethnicity.