Prevalence and age patterns of depression in the United Kingdom. A population-based study

Methods: A representative sample of the UK population (n=17,152) from the European Health Interview Survey of 2014 was included in the analyses. The Patient Health Questionnaire (PHQ-8) was used to assess the prevalence of depressive symptoms and of probable depressive disorder. Prevalence estimates (95%CI) were calculated. The association between prevalence and age was assessed using multivariable multinomial logistic and logistic regression models. All analyses were carried out for the total sample and stratified by sex. Results: The prevalence of depressive symptoms ranged from 11.3% (10.6-11.9) for mild, to 3.3% (3.0-3.7) for severe symptoms. The prevalence of probable depressive disorder was 7.5% (95%CI: 7.0-8.0). A significantly higher prevalence of probable depressive disorder was found in those aged 45 to 59 years old compared with those aged 16 to 29. For the prevalence of severe depressive symptoms those age differences were even higher: 2.55 times higher (5.38 for men and 1.75 for women). Limitations: The cross-sectional design precludes stablishing the direction of the relationship between age and the prevalence. Conclusions: The prevalence and age patterns of depression in the UK were described. A peak in the prevalence was identified during middle adulthood. These results could serve as a reference for the monitoring of depression in the UK and the development of preventive strategies, particularly in the high-risk population groups identified.