Unintended Impacts of a Medicaid Prior Authorization Policy on Access to Medications for Bipolar Illness

This article examines the effects of a prior authorization policy put into effect by Maine Medicaid to control the cost of psychotropic medications.

Little is known about whether such prior authorizations have unintended consequences on treatment for mental illness. The Maine prior authorization policy requires that bipolar patients receiving second-generation antipsychotics must be treated first with preferred medications before receiving reimbursement for non-preferred medications. The authors compared data from 5,336 Maine residents with bipolar disorder with a control group of 1,376 patients from New Hampshire. Using an interrupted time series with a comparison group allowed researchers to study the implementation of the Maine prior authorization policy.

Key Findings:

  • The Maine prior authorization policy was associated with a 32 percent reduction in rates of initiation for bipolar treatment. This decrease was almost entirely caused by a decrease in the number of initial prescriptions for non-preferred medications.
  • Among patients already established on a non-preferred bipolar treatment, there was no significant change in the frequency of treatment switching. This is consistent with the intent of the prior authorization which grandfathered in patients already prescribed non-preferred treatments.
  • There was an overall decrease in the number of Maine patients who started a new therapy for bipolar illness, possibly due to the administrative demands of the prior authorization policy.

These findings suggest that the prior authorization policy achieved its goal of reducing the number of new patients prescribed non-preferred treatments, while not affecting the treatment patterns of patients already established on non-preferred medications.