National psychotropic prescription dispensation among dually diagnosed patients

Abstract

PurposeThe purpose of this paper is to determine if dually diagnosed (DDx) patients with severe mental illnesses such as bipolar disorder and schizophrenia are at higher risk of not obtaining prescribed medication.Design/methodology/approachNational Veterans Health Administration records from 2010 identified all DDx patients with Bipolar (BP) spectrum (n=98,894) and Schizophrenia (SZ) spectrum (n=80,654) disorders. Pharmacy records identified the total number of prescriptions dispensed per veteran for antidepressants, antipsychotics, sedative‐hypnotics and anxiolytics, mood stabilizers (anti‐convulsants), and lithium. To identify potential sociodemographic and clinical confounders, bivariate analyses compared four groups: BP and SZ with and without DDx. Analysis of covariance (ANCOVA) was used to determine the association of DDx with the number of dispensed prescriptions, and interaction analysis was used to determine whether any “dual‐diagnosis effect” was greater between BP or SZ. Further ANCOVA examined whether significant differences were accounted for by differences in outpatient mental health visits or co‐morbidities.FindingsAmong BP veterans, 33,226 (33.6 percent) were DDx, compared to 19,652 (24.4 percent) among SZ veterans. DDx patients obtained more prescriptions than other patients over a similar period of time, and these effects were somewhat greater for BP DDx patients than for SZ DDx patients. DDx patients also showed more mental health services use and had more co‐morbidities. After controlling for these differences, DDx veterans still were dispensed more total psychotropic prescriptions, but most differences between diagnostic groups and medication class were no longer significant.Originality/valueThe paper shows that DDx veterans consume more resources in terms of both psychotropic medications and clinic visits. Further attention should be paid to the overall complexity of their clinical needs, including the increased likelihood of both licit and illicit drug‐drug interactions rather than just to their substance use.