BackgroundHigh demand for health services is an issue of current importance in England, in part because of the rapidly increasing use of emergency departments (EDs) and GP practices for mental health conditions and the high cost of these services.AimTo examine the social determinants of health service use in people with mental health issues.Design and settingTwenty-eight neighbourhoods, each with a population of 5000–10 000 people, in the north west coast of England with differing levels of deprivation.MethodA comprehensive public health survey was conducted, comprising questions on housing, physical health, mental health, lifestyle, social issues, environment, work, and finances. Poisson regression models assessed the effect of mental health comorbidity, mental and physical health comorbidity, and individual mental health symptoms on ED and general practice attendances, adjusting for relevant socioeconomic and lifestyle factors.ResultsParticipants who had both a physical and mental health condition reported attending the ED (rate ratio [RR] = 4.63, 95% confidence interval [CI] = 2.86 to 7.51) and general practice (RR = 3.82, 95% CI = 3.16 to 4.62) more frequently than all other groups. Having a higher number of mental health condition symptoms was associated with higher general practice and ED service use. Depression was the only mental health condition symptom that was significantly associated with ED attendance (RR = 1.41, 95% CI = 1.05 to 1.90), and anxiety was the only symptom significantly associated with GP attendance (RR = 1.19, 95% CI = 1.03 to 1.38).ConclusionMental health comorbidities increase the risk of attendances to both EDs and general practice. Further research into the social attributes that contribute to reduced ED and general practice attendance rates is needed.