Background The need for effectiveness and dissemination research is at least as great in mental health as in other areas of health care. The Mental Health Research Network aims to use the VDW for multi-site studies of mental disorder epidemiology, treatment patterns, or treatment effectiveness. We expect that the existing infrastructure is satisfactory in some areas, while others will need improvement or expansion. We present early results from validation studies of enrollment and pharmacy data on patterns of psychotherapeutic drug use.

Methods We identified the relevant denominator populations using existing VDW variables indicating continuous enrollment with any drug coverage in 2009. After developing National Drug Code (NDC) lists for drugs used in the treatment of depression, bipolar disorder, attention-deficit disorder, and other mental health conditions, we calculated rates of use of these drugs across ten health plans in 2009.

Results Antidepressant exposure rates vary across sites, although our data include no diagnostic criteria and will include uses for other conditions. Initial results indicate overall antidepressant use rates vary more than two-fold between ten sites, from 62 to 162 exposures per thousand members. In addition, the preferred member of a class (for example SSRIs), and the rate of any pharmacy utilization also differs across sites, although to a lesser degree.

Conclusions Data validation is an iterative process where results are compared to what is known and expected and discrepancies are investigated. The considerable variation in overall antidepressant exposure rates at different sites is unexpected, based on reports of the incidence of depression (ref) and warrants further exploration. Possible explanations include use of antidepressants for other conditions, cultural attitudes toward mental health treatment in different populations, or delivery system practices. Alternatively, they may be artifacts of information systems or incorrect interpretations of the underlying data. These possibilities can be explored with a combination of local expertise from each delivery system and further analysis of VDW data.