This article presents estimates indicating that few dually eligible Medicare and Medicaid beneficiaries with mental health problems will experience significant treatment disruptions as a result of the Medicare Part D drug benefit.  However, the authors note that some beneficiaries will encounter significant difficulties accessing needed medications and suggest that agencies and clinicians provide extensive guidance to beneficiaries choosing Medicare drug plans. 

Donohue, J. M., & Frank, R. G. (2007). Estimating Medicare Part D's impact on medication access among dually eligible beneficiaries with mental disorders. Psychiatric Services, 58(10): 1285-91. DOI: 10.1176/appi.ps.58.10.1285.  http://psychservices.psychiatryonline.org/cgi/content/abstract/58/10/1285

Authors: Julie M. Donohue, Richard G. Frank