We have been conducting a psychiatric morbidity study to assess the prevalence of major psychiatric disorders in one of the districts in the state of Kelantan, on the east coast of peninsular Malaysia. "Probable cases" were detected through key informants after field workers presented five vignettes portraying mental retardation, acute psychosis, chronic schizophrenia, mania, and depression. At the end of the interview, the informants were asked whether they had observed any person in the village matching the description in the vignettes.