Effects of collaborative care on recognition and management of common mental disorders by general practitioners: a cluster-randomised trial in Norway

Abstract Background The aim of the study was to determine the effects on health care of an adapted Norwegian version of a Canadian model of collaborative care, involving general practitioners (GPs) and mental health specialists working together co-located in GP practices. In previous papers, we have shown that the adapted model was successfully implemented and found to be beneficial by participating GPs, improving their detection of anxiety in young people, and with a reduction in long term sickness benefits. The current study examines whether collaborative care was associated with changes in (a) the number of referrals from GPs to mental health services, (b) the number of GP patients provided outpatient visits in mental health services, (c) GPs’ recognition of common mental disorders, and (d) GPs’ prescription of various types of psychotropic medication. Methods The study was a cluster-randomised controlled trial of the collaborative care model in three GP practices (intervention group) compared with usual health care in three other practices (control group) in Oslo, Norway. A clinical psychologist and a psychiatrist from a community mental health centre worked half time and two hours per week, respectively, in each intervention practice for 18 months. They were available for case discussions and provided assessments and brief therapies. Structured data were extracted retrospectively from the electronic patient records of both GPs and mental health services for 12 months before and during the implementation of collaborative care for patients 16–65 years old. Data were analysed with generalized linear mixed models. Results There were no significant differences in referrals to mental health services (the primary outcome) and in the use of outpatient specialised mental health services. The GPs in the intervention practices diagnosed significantly more patients with common mental disorders (anxiety, depression), and these changes were significantly associated with a reduction in unexplained physical symptoms. Significant changes in prescribing patterns of psychotropic medication were consistent with the increased recognition of mental disorders, and their use was possibly more appropriate. Conclusions Collaborative care with co-located mental health specialists in GP practices led to an increased recognition of common mental disorders by those GPs. Due to a lack of structured clinical measurements in the electronic patient records, the clinical outcomes of the intervention were unknown.