AMELIA ISLAND, FLA. -- Underrecognition of psychiatric disorders in many ethnic minorities has led to an increased risk of substance abuse and violence, according to Dr. William B. Lawson.
A major research initiative is underway to study how ethnicity and culture contribute to differences in diagnosis and management of bipolar disorder, depression, and posttraumatic stress disorder in the United States. In January the National Institute of Mental Health awarded a $6.5 million grant to support the 5-year project. All research will be coordinated through Howard University in Washington, where principal investigator Dr. Lawson is chairman of psychiatry.
Misperceptions among health care staff also have led to differential treatment for minorities, Dr. Lawson said at the annual meeting of the American Academy of Addiction Psychiatry. African Americans and Hispanics, for example, are more likely to be admitted for inpatient care, leave treatment against medical advice, or be in voluntarily committed.
"Staff consistently perceive African American patients as being more violent despite no difference in objective measures," he said.
Hostility is a common consequence of substance abuse, but its incidence is no higher among minorities. However health care professionals tend to perceive African Americans with psychiatric disorders as more hostile, he said. "African Americans may be perceived as being more hostile because of lack of cultural sensitivity by staff."
Another comorbidity of substance abuse that often is unrecognized in minorities is bipolar illness, Dr. Lawson re ported. "And of the Axis disorders, it is probably the one most often associated with violent behavior and substance abuse." Another problem is that bipolar disorder and other mood disorders are often misdiagnosed as schizophrenia in African Americans or not diagnosed at all.
"When I was in medical school, it was thought that African Americans didn't get depression," Dr. Lawson said. In reality, half of African Americans with depression are undiagnosed, and of those who are diagnosed, more than half do not get adequate treatment.
Ethnicity can play a role in pharmacodynamics and pharmacokinetics as well. For example, there is genetic basis in how different ethnic groups metabolize psychoactive drugs through the cytochrome P450 system.
Specifically, researchers have identified the differing extent to which the CYP2D6 and CYPmp enzymes metabolize tricyclic antidepressants, neuroleptics, benzodiazepines, barbiturates, and propanolol (K.M. Lin et al. Overview: The interface between psychobiology and psychiatry. In: K.M. Lin, R.E. Poland, and G. Nakasaki, eds. "Psychopharmacology and Psychobiology of Ethnicity." Washington, D.C.: American Psychiatric Association, 1993, 11-35).
Because African Americans and Asians are slower metabolizers of many psychoactive agents, "they experience higher side effects than what you might see in Caucasians," Dr. Lawson explained.
For example, although rare among whites, as many as 20% of Chinese and Japanese are poor metabolizers through the CYPmp enzyme (K.M. Lin and R.E. Poland. Ethnicity, Culture, and Psychopharmacology. In: F.E. Bloom and D.J. Kupler, eds. "Psychopharmacology: The Fourth Generation of Progress." New York: Raven Press, 1995, 1907-17).
Other researchers have found a significantly higher rate of poor metabolizers among African Americans compared with whites (U.A. Meyer. Molecular genetics and the future of pharmacogenetics. In: W. Kalow, ed. "Pharmacogenetics of Drug Metabolism." New York: Pergamon Press, 1992, 206-11).
It is also well documented that African Americans experience more side effects from lithium treatment. A study comparing 12 African Americans and 22 Caucasians with bipolar affective disorders found the first group reported significantly more side effects on the general side effects (GSE) scale (Biol. …