Access and Utilization of New Antidepressant and Antipsychotic Medications. Chapter VI. Patterns of Antipsychotic and Antidepressant Utilization in Medicaid, 1995-1998


The truest measure of access to and utilization of pharmaceuticals is analysis of actual patterns of claims processed for individual drugs. Although analysis of these patterns across all health care payers is outside the scope of this research, this section analyzes trends in utilization of antidepressants and antipsychotics in Medicaid between 1995 and 1998.

In brief, this analysis found:

Antidepressants and antipsychotics account for a large proportion of Medicaid pharmaceutical prescriptions and reimbursements. The impact of newer antidepressants and antipsychotics on expenditures is out of proportion to the number of prescriptions for these agents.

  • In 1998, antidepressants and antipsychotics accounted for 9% of Medicaid prescriptions but 19% of Medicaid drug expenditures.
  • Although the total number of prescriptions reimbursed by Medicaid has remained relatively constant between 1995 and 1998, expenditures have increased by over 40%.
  • The growth rate in both number of prescriptions for and cost of antidepressants and antipsychotics outpaces that observed in Medicaid pharmacy benefits as a whole by more than 2-fold.

The volume of Medicaid antidepressant and antipsychotic prescriptions grew dramatically between 1995 and 1998.

  • Medicaid antipsychotic prescriptions increased nearly 20% between 1995 and 1998.
    • Antipsychotic prescriptions totaled 9.1 million in 1995.
    • Antipsychotic prescriptions totaled 11 million in 1998.
  • Medicaid antidepressant prescriptions grew by over 40% between 1995 and 1998.
    • Antidepressant prescriptions totaled 13.6 million in 1995.
    • Antidepressant prescriptions totaled 19 million in 1998.

Total expenditures by Medicaid programs for antidepressants and antipsychotics grew dramatically between 1995 and 1998.

  • Medicaid antipsychotic expenditures increased nearly 160% between 1995 and 1998.
    • Antipsychotic expenditures totaled $484 million in 1995.
    • Antipsychotic expenditures totaled $1.3 billion in 1998.
  • Medicaid antidepressant expenditures grew by over 96% between 1995 and 1998.
    • Antidepressant expenditures totaled $592 million in 1995.
    • Antidepressant expenditures totaled $985 million in 1998.

New generation antipsychotics been accepted into common use within Medicaid programs.

  • In 1998, 51% of the 11 million prescriptions for antipsychotics were for atypical antipsychotics. Three 2nd generation atypicals were available in 1998.
    • In contrast, atypicals accounted for only 17.5% of 9.1 million Medicaid antipsychotic prescriptions in 1995. Only one 2ndgeneration atypical was available in 1995 (risperidone).
      • The use of atypical antipsychotics in Medicaid has more than doubled since 1995.
      • Concomitantly, the use of typical antipsychotics in Medicaid has dropped by 25% since 1995.

New generation antipsychotics have not simply supplanted typical antipsychotics. Rather the total market for antipsychotics in Medicaid has grown since their introduction. Increased use of atypical antipsychotics has driven expenditures.

New generation antidepressants have been accepted into common use in Medicaid.

  • In 1998, 62% of the 19 million Medicaid antidepressant prescriptions were for new-generation, branded antidepressants.
    • In contrast, new generation antidepressants accounted for from 44% of 13.6 million Medicaid antidepressant prescriptions in 1995.
      • The market share of new generation antidepressants has grown by approximately 50% since 1995.
      • Concomitantly, the market share of TCAs in Medicaid has decreased by nearly 50%.
  • The selective serotonin reuptake inhibitors (SSRIs) comprised 46% of total antidepressant prescriptions in 1998.
    • Prescriptions for the three leading agents (fluoxetine, paroxetine, and sertraline) were nearly equal with approximately 3 million prescriptions each, or a 15-16% share each.
  • Tricyclic antidepressants accounted for 27% of total prescriptions in 1998.

Increased Medicaid expenditures for antidepressants have been driven both by uptake of new generation, branded agents and increased prescription volume.

  • Much of this increase can be attributed to the steady, yet significant rise of the three leading SSRI antidepressants (fluoxetine, sertraline, and paroxetine).
    • Together, spending for fluoxetine, sertraline and paroxetine comprised over 70% of all Medicaid spending on antidepressant drugs in 1998 ($711 million).
  • TCAs accounted for only 5% of all Medicaid dollars reimbursed for antidepressants ($54 million).

New generation antidepressants have not simply supplanted tradition antidepressants. Rather the total market for antidepressants in Medicaid has grown since their introduction.

Utilization of new-generation antidepressants and antipsychotics varies among the states. Not all states have adopted new-generation agents as quickly as others.

New-generation antidepressants and antipsychotics have been accepted into common use by Medicaid programs at about the same rate and to the same extent as other innovator drugs.

  • Newer antipsychotics appear to be proportionally more expensive than other new generation pharmaceuticals such as oral antidiabetics.
  • Newer antidepressants appear to be roughly equivalent in cost to these other classes.