Primary Care Mental Health Integration in the VA: Shifting Mental Health Services for Common Mental Illnesses to Primary Care

Objective: Primary care-mental health integration (PC-MHI) aims to increase access to general mental health specialty (MHS) care for primary care patients thereby decreasing referrals to non-primary care-based MHS services. It remains unclear whether new patterns of usage of MHS services reflect good mental health care. This study examined the relationship between primary care clinic engagement in PC-MHI and use of different MHS services. Methods: This was a retrospective longitudinal cohort study of 66,638 primary care patients with mental illnesses in 29 Southern California Veterans Affairs clinics (2008-2013). Regression models used clinic PC-MHI engagement (proportion of all primary care clinic patients who received PC-MHI services) to predict relative rates of general MHS visits and more specialized MHS visits (for example, visits for serious mental illness services), after adjustment for year and clinic fixed effects, other clinic interventions, and patient characteristics. Results: Patients were commonly diagnosed as having depression (35%), anxiety (36%), and posttraumatic stress disorder (22%). For every 1 percentage point increase in a clinic's PC-MHI engagement rate, patients at the clinic had 1.2% fewer general MHS visits per year (p<.001) but no difference in more specialized MHS visits. The reduction in MHS visits occurred among patients with depression (-1.1%, p=.01) but not among patients with psychosis: however, the difference between the subsets was not statistically significant. Conclusions: Primary care clinics with greater engagement in PC-MHI showed reduced general MHS use rates, particularly for patients with depression, without accompanying reductions in use of more specialized MHS services.