Ever since the syndrome of tardive dyskinesia was introduced into the literature more than 30 years ago, older age has been the only consistent risk factor confirmed by most authors (Smith & Baldessarini, 1980). However, several other factors, detailed elsewhere in this volume, have now been implicated.

Gender has been suggested to be an important factor in the development of tardive dyskinesia, and whereas some authors have concluded that women have a higher prevalence of tardive dyskinesia than do men, others have found no gender difference (Jeste & Wyatt, 1981). Elsewhere, we have reviewed, in detail, the studies that discussed and compared the prevalences of tardive dyskinesia for the two genders (Yassa & Jeste, 1992). Only articles published in English or French (or in other languages, if a detailed summary was provided in English or French) were reviewed. We found 93 English or French prevalence studies published prior to the end of 1989. To be included in our review, a study had to meet the following criteria:

• report on 50 patients or more. The study by Crane and Smeets (1974), a study of 39 patients, was therefore excluded.

• include both genders in its sample. We excluded three women-only studies (Uhrbrand & Faurbye, 1960; Pryce & Edwards, 1966; Edwards, 1970) and two studies of men only (Dynes, 1970; Goldberg et al., 1982).

• include the numbers of men and women affected by tardive dyskinesia. Eleven studies were excluded (Paulson, 1968; Yagi et al., 1976; Bell & Smith, 1978; Alexopoulos, 1979; Gardos et…