Doctors are less likely to prescribe antidepressants for depressed African Americans and Latinos than they are for whites, and are less likely to prescribe newer antidepressants for Medicare and Medicaid patients than those not on either program, according to a University of Michigan School of Public Health study published in the International Journal of Psychiatry in Medicine.

For the study, researchers looked at data showing doctors’ antidepressant prescribing patterns from 1993 to 2007. Scientists found doctors were 50 percent more likely to prescribe antidepressants for whites with major depressive disorder than they did for African Americans or Latinos. What’s more, researchers also found that Medicare and Medicaid patients were 31 and 38 percent less likely to receive antidepressants, respectively, than those with private insurance.

Additional findings also showed the following patterns:

  • Doctors in metropolitan areas were 27 percent less likely to prescribe antidepressants to patients than those in less urban areas.
  • Sole practitioners—physicians who owned their own personal practices—were 25 percent less likely to prescribe antidepressants than non-owners.
  • People on Medicare and Medicaid were 58 and 61 percent less likely to receive newer antidepressants, respectively, than those on private insurance.
  • People insured by a health maintenance organization (HMO) were 219 percent more likely to get newer antidepressants than those not in an HMO.
  • And doctors in the Northeastern United States were 43 percent less likely to prescribe newer antidepressants than those in Western states. (Northeastern physicians were also 43 percent less likely to prescribe combination antidepressant therapy.)

Important variations also revealed that doctors’ antidepressant prescribing patterns differed depending on how they classified patients.

This data is important because antidepressants developed recently have fewer side effects than the older ones.

But these prescribing variations can be addressed, researchers said. A way to do it, said Rajesh Balkrishnan, PhD, an associate professor at the university and the study’s lead author, is for policy makers to design interventions that improve physicians’ adherence to practice guidelines. This way, all patients could receive optimal health care.