Use of AntiDepressant medication (AD) without an accompanying Mood Stabilizer medication (MS) can lead to mood instability, including mania, among susceptible individuals with BiPolar disorder, type I (BPI). Accordingly, clinical practice guidelines recommend avoidance of such AntiDepressant Monotherapy (ADMono). It has been assumed that ADMono use is low; however, empirically-based information is largely nonexistent. Given the potential for deleterious patient outcomes, information about the rate, predictors, and outcomes is needed.
Study aims were to (1) determine the Fiscal Year (FY) 2008 nationwide rate of ADMono to Veterans Health Administration (VHA) patients with BPI; (2) identify patient and treatment factors that predict ADMono rather than the recommended treatments of MS Monotherapy (MSMono) and concurrent use of AD and MS (ADMS); and (3) evaluate whether ADMono, more so than recommended treatment, is associated with greater risk of subsequent mania- or depression-related treatment.
This retrospective database project utilized FY2002-FY2010 VHA administrative information (NPCD, DSS Pharmacy, Vital Status File, Fee Basis). A nationwide cohort of unique patients with BPI treated in FY2008 was identified. Cohort members had at least two unique treatment encounters in FY2002-FY2007 for which a BPI ICD9CM code (296.0x; 296.1x; 296.4x; 296.5x; 296.6x; 296.7) was listed first or second without conflicting evidence of schizophrenia. In FY2008, all cohort members used VHA non-pharmacy services and filled at least one prescription for an AD or MS. Medication coverage by ADMono, ADMS, and MSMono was calculated using day-level prescription data and required a minimum of 30 continuous days of use. "New" prescriptions required that there be no medication coverage of the specified type for at least 90 days prior to the prescription fill date. Multiple logistic regression analysis was used to identify predictors and outcomes of new FY2008 ADMono prescriptions.
There were 68,734 unique individuals with BPI treated in FY2008. Among these, 73.9% filled at least one AD prescription, 38.6% filled an ADMono prescription, and 8.5% filled a new ADMono prescription. Compared to patients who received ADMS or MSMono, patients who received a new ADMono prescription had a history of less treatment for mania but more for depression; were less likely to have previously filled prescriptions for ADMS or MSMono, but had used ADMono more; and were less likely to have a recently recorded depression diagnosis but more likely to have non-psychiatric conditions for which ADs are sometimes used. About half of patients receiving new ADMono were treated solely outside Mental Health (MH) specialty care settings. In analyses evaluating the 90-day outcomes of ADMono while controlling for identified predictors, patients receiving ADMono were not more likely than those receiving recommended treatment to obtain treatment for mania but were for major depression.
A sizeable gap exists between recommended and actual prescription of ADMono among patients with BPI. Efforts to reduce this gap should focus on patients who seek care outside MH specialty settings for non-psychiatric conditions for which ADs are sometimes used. Evaluation of these efforts should consider depression- as well as mania-related outcomes.
- Schutte KK, Hu KU, Balasubramanian V, Schmitt SK, Dally SK, Phibbs CS. Rate and Predictors of Tricyclic Antidepressant Monotherapy to Patients with Bipolar I Disorder. Presented at: VA HSR&D / QUERI National Meeting; 2012 Jul 19; National Harbor, MD.
- Schutte KK, Hu KU, Schmitt SK, Phibbs CS. Comparison of Alternative Methods for Identifying DSS (Decision Support System) Pharmacy Prescription Records. Poster session presented at: VA HSR&D National Meeting; 2011 Feb 18; National Harbor, MD.