Screening for common mental disorders: who will benefit? Results from a randomised clinical trial

BACKGROUND: Outcomes of studies on mental health screening in primary care are conflicting. A feasible and effective case-finding approach could benefit both GPs and their patients. OBJECTIVES: (1) to examine the effect of using a composite screening questionnaire (SQ) on GPs' recognition and provision of care, and (2) to outline useful strategies for case-finding. METHODS: 38 GPs in Aarhus County, Denmark, volunteered to participate in this trial. 1785 consecutive patients aged 18-65 years consulting with new health problems were included. Patients were screened before consultation using an SQ including scales for somatisation, anxiety, depression and alcohol abuse. Patients were randomised into one of two groups: 900 questionnaires were disclosed to and scored by GPs, 885 were blinded. Number of diagnoses, subjects of conversation, and actions taken were analysed. Additional analyses aimed to identify GP and patient factors that could predict improved outcomes. RESULTS: Overall, disclosure of SQ results increased GPs' recognition of mental disorders by 3.8% 95% confidence interval (CI) -0.5% to 8.0%, and 6.6% (95% CI 1.2% to 12.0%) for patients screened positive. There was a marked variation in GPs' detection rates, and for GPs with moderate or low recognition rates increases were significant (P = 0.001). Conversation on psychological topics increased by 3.2% (95% CI -0.7% to 7.1%), and by 7.0% (95% CI 1.8% to 12.3%) for patients screened positive. Rates of planned follow-up consultations increased by 3.9% (95% CI 0.6% to 7.3%) and by 4.9% (95% CI 0.7% to 9.1%) for patients screened positive. GPs' self-reported benefit from screening was related to better outcomes. A range of patient and GP factors suggesting added value from using SQs were identified. CONCLUSION: GPs' recognition and provision of mental health care can be influenced by the use of composite SQs. Perceived benefit from screening may serve as a useful predictor of better patient management. Pragmatic case-finding approaches need further evaluation.