The types and dosages of psychotropic medications may differ significantly in different countries or regions or even in the same clinical setting. African-American patients may be less likely than white patients to receive second-generation antipsychotics or selective serotonin reuptake inhibitors (
3,
4). Among veterans with schizophrenia, overall use of second-generation antipsychotics has been reported to be slightly less common, and use of clozapine much less common, among African Americans and Hispanics than among whites (
5). Because patients from ethnic minority groups may not receive first-line recommended treatments, they may have less clinical improvement than white patients and be exposed to a greater risk of side effects, including extrapyramidal symptoms. Differences in prescribing patterns may also contribute to the lower rates of adherence and to the more frequent emergency department visits and psychiatric hospitalizations that have been reported among African Americans (
6).
Some reports have indicated that Asians and Hispanics typically require lower dosages of psychotropic medications than whites (
7,
8), although others have noted conflicting findings (
9,
10). A frequently cited study by Lin and Finder (
7) found that Asians required lower dosages of chlorpromazine equivalents than whites, although the overall dosages were very high: Asians received a mean of 1,000 mg equivalents daily and whites received more than 2,000 mg equivalents daily. During the same period, less than 20 miles from the study location, a research team used a mean dosage of 355 mg of chlorpromazine to treat a group of similar non-Asian inpatients (
11), suggesting that providers' practicing habits are largely responsible for noted dosage differences. African Americans, in both inpatient and outpatient settings, often receive higher dosages of antipsychotic medications (
1,
2,
12,
13) and are more apt to be prescribed long-acting depot preparations (
4,
14). However, a more recent study from Great Britain found that dosages of two widely used second-generation antipsychotics, olanzapine and clozapine, did not differ significantly between Asians, African Americans, and whites (
15).
Some cross-cultural differences have been reported for therapeutic and side effects of psychotropic medications. One study found that compared with whites, Asians manifested significantly more extrapyramidal side effects from haloperidol during an initial fixed-dose phase. The study also found that Asians required significantly smaller doses during the clinically determined, variable-dose phase, resulting in lower plasma concentrations of haloperidol for an optimal response (
16). This and other studies imply that Asians should receive lower dosages of antipsychotics because the therapeutic and extrapyramidal effects of these medications may occur at a lower percentage of dopamine receptor blockade. These studies also suggest that genetically determined biological factors are important to consider when using these psychotropics. However, increased rates of side effects may be secondary to incorrect diagnoses or to the higher dosages of medications given to certain ethnic groups. For example, the fact that African Americans are more frequently given prescriptions for first- rather than second-generation antipsychotics and that they receive higher dosages of these medications may account for the observation that they may be more sensitive than whites to antipsychotic side effects, including tardive dyskinesia (
1,
17,
18,
19). Thus both genetic and environmental factors need to be considered in the cautious use of antipsychotic medications (
20,
21).