In this paper we review the psychiatric literature focusing the effects of ethnicity on the effectiveness and tolerability of psychopharmacological compounds. Recently, our society has become more ethnically and culturally diverse. During the last few decades, much attention has been given to cross-cultural psychiatry. Similarly, given the current high rates of immigration, much attention focused on the clinical needs of ethnic minority populations. Additionally, globalisation has oriented research toward the psychiatric needs of multi-ethnic groups. The rapid movement of populations around the world means that many psychiatrists are increasingly faced with providing treatment for individuals who come from cultures about which they know little. The characteristics of mental illness itself may prove challenging in such circumstances, as it can be influenced by cultural differences in, for example, the degree of somatisation of symptoms. Research has shown ethnic differences in clinical presentation, treatment, clinical response, and outcome of mental illnesses.
PubMed and PsycInfo (1970-2009) databases were searched for english language articles using the keywords: ethnicity, psychotropic drugs, pharmacokinetics, pharmacodynamics, pharmacogenetics, transcultural psychiatry. We reviewed papers that addressed the following aspects of ethno-psychopharmacology: 1. ethnic differences in clinical response to psychopharmacologic treatment of mental disorders; 2. research to determine accurate pharmacodynamic and pharmacokinetic profiles across different ethnic groups; 3. biological and cultural factors influencing individual response to drugs. Ethnicity is reported to be an important, but often ignored factor in psychopharmacology. The association between ethnicity and pharmacology has been reported in the medical literature for several decades. However, the relationship between ethnicity and psychopharmacology has become widely recognised only in the last few years. Biological factors influencing individual response to drugs are being extensively studied in psychiatry. Most of the psychiatric medications have been developed in the occidental countries. The safety trials for almost all the psychopharmacologic compounds have been conducted in the populations living in these parts of the world. Although these drugs are used all over the world there is a limited research to determine accurate pharmacodynamic and pharmacokinetic profiles across different ethnic groups.
Ethnic differences in pharmacodynamics are clearly demonstrated. In fact, Caucasians are more sensitive to a variety of drugs than Asians or African-Caribbeans. A number of ethnically-specific variations were found in the genetic and non-genetic mechanisms affecting pharmacokinetics and dynamics of psychotropic drugs, which might underlie the differences in drug use and response across ethnicities. There are several factors that must be taken into consideration in making decisions about medication that depend on patient’s ethnicity. A recently recognised key factor in the study of pharmacokinetics is pharmacogenetics. An ethnic group-related pharmacogenetic variation may lead to significant genetically-determined modifications of metabolising enzymes (Tab. III). This, in turn, leads to differing therapeutic levels and half-lives and, therefore, variable therapeutic and adverse effect profiles. In particular, some studies reported dramatic cross-ethnic and cross-national variations in dosing practices and side-effect profiles in response to practically all classes of psychotropics.
Anthropologists have described “ethnocentrism”, a general tendency of people from one culture to unconsciously perceive and value other cultures in terms of their own values, but phenomenologically considered as absolute and universally applicable. In addition to ethno-biological determinants of drug response, there are significant cultural factors, like the concurrent use of pluralistic health systems, alternative therapies and folk remedies which might support, hinder or complicate pharmacotherapy and treatment adherence. There are few studies addressing social and cultural differences in attitudes toward psychotropic medications. In this brief review article we highlight some key factors which clinicians need to be aware of. The effectiveness of pharmacological treatment for psychiatric problems could be influenced significantly by the ethnic and cultural background of the patient (Tables IV-V).