David Henderson, M.D., is an associate professor of psychiatry at Harvard Medical School. Some years ago he worked in Cambodia and had an experience he said he'll never forget.

Whenever during an evaluation he asked Cambodian patients whether they heard voices, they invariably said yes. This experience made him wonder: Could so many Cambodians have psychosis? He then asked the Cambodian minister of health whether he heard voices. The minister also said yes. And then he asked some of his Cambodian colleagues the same thing. Again the answer was positive. Finally one of them said, "It looks as if Dr. Henderson is the only one among us who has not been in touch with his ancestors!"

"This experience was really humbling for me," Henderson acknowledged at a session on the cultural aspects of psychiatry at the APA annual meeting in May, because it showed that a hallmark symptom of psychosis in the West may not necessarily indicate psychosis in Cambodia. In other words, cultural differences can truly influence patients' presentation of psychiatric disorders.

The other four speakers—David Mischoulon, M.D., Ph.D.; Shamsah Sonawalla, M.D.; Rajesh Parikh, M.D.; and Albert Yeung, M.D., Sc.D.,—agreed with him. Mischoulon and Yeung are associate professors of psychiatry at Harvard Medical School. Sonawalla is an adjunct assistant professor of psychiatry at Duke University. Parikh is director of psychiatric research at the Jaslak Hospital and Research Center in Mumbai, India.

For example, in India, China, and Latin cultures, they said, patients often express their depression through somatic symptoms rather than through psychological ones. And some Hispanic patients experience culture-bound syndromes that non-Hispanic psychiatrists may find difficult to diagnose and treat, Mischoulon pointed out—say, an "attack of nerves," which is similar to a panic attack, but more violent, involving fainting or seizures.

Culture can also influence psychotherapy preference, the speakers said. For example, Indian psychiatric patients prefer brief psychotherapies with quick solutions and like the therapist to provide suggestions and be actively involved, Parikh stated. In contrast, supportive psychotherapy can be very helpful for Hispanics, Mischoulon said. Yet family involvement is important to both Indian and Hispanic patients, Parikh and Mischoulon noted.

And ethnic differences in drug metabolizing can influence psychotropic medication responses, Henderson reported. For example, the CYP2D6 enzyme is very important for metabolizing psychotropic medications, and there are ethnic differences in this enzyme that can change the way in which it responds to medications. As a result, some patients are slower or faster metabolizers. "We are more likely to see metabolism problems in Africans and Asians than in Caucasians, and Ethiopians are especially rapid metabolizers," Henderson said.

Also compounding this issue, Henderson noted, is that diet is capable of influencing CYP2D6 enzyme activity. Several other drug-metabolizing enzymes are also known to be influenced by diet. For example, CYP3A4 is inhibited by grapefruit juice or corn, and CYP1A2 by coffee.

So the maxim, "Start low and go slow" is good advice not just for prescribing psychotropic medications in general, but particularly for patients who are not Caucasian, Henderson advised.