Temporal patterns in the recorded annual incidence of common mental disorders over two decades in the United Kingdom: a primary care cohort study

BACKGROUND: Common mental disorders (CMDs) including depression, anxiety, and stress are very common, but it is unclear whether the last decades of social, economic, and political change have impacted incidence of CMD. This study explored temporal trends in the recorded incidence of CMD in the United Kingdom. METHODS: We used data from general practices in the United Kingdom (Clinical Practice Research Datalink) to estimate the annual recorded incidence of CMD for 2000-2020, including symptoms, diagnosis, or pharmaceutical treatment. Trends were explored by sex, age, ethnicity, region, deprivation, and comorbidity. RESULTS: We included 29 480 164 individuals who were followed up for 12.5 years on average (s.d. = 6.4 years). The recorded incidence of CMD episodes was 55.9 per 1000 person-years in 2000 [95% confidence interval (CI) 55.8-56.1], increasing to 79.6 per 1000 person-years in 2019 (95% CI 79.5-79.8). Females had higher recorded incidence rates, as did those living in more deprived areas. We observed striking patterns by age over time, with rates in ages 16-24 increasing from 40.2 per 1000 in 2000 (95% CI 39.8-40.5), to 107.8 per 1000 in 2019 (95% CI 107.0-108.6). In contrast, the rates in those aged ≥55 years decreased since 2014. There were differing patterns of incidence by ethnic group, with a steeper increase in Asian, Black, and mixed groups in recent years. CONCLUSIONS: Overall, the incidence of recorded CMD in the UK general practice increased between 2000 and 2019 with a small decrease in 2020. The overall trends obscured important differences across population subgroups, which may have implications for prevention.