There are few reports of the prevalence of psychotic disorders among isolated population groups. Where present, variations in prevalence estimates raise questions about the validity of methods of case ascertainment in such settings. In a previous population-based survey of the Borana pastoralist community in Ethiopia using the Composite International Diagnostic Interview, no cases of schizophrenia were identified. In order to further explore this finding and investigate how serious mental disorder is conceptualized, we conducted focus group discussions with key members of the Borana pastoralist community. Subsequently, focus group participants were used as key informants to identify cases with possible psychotic disorder, based on their conceptualization. Cases identified by key informants were interviewed by a trained psychiatrist using the Schedules for Clinical Assessment in Neuropsychiatry (SCAN), to confirm presence of disorder. Focus group discussions were subjected to thematic analysis. The incongruity between local and psychiatric concepts lay mainly in the fact that key informants described characteristics of marata ("madness") in terms of overt behavioural symptoms. Following the focus group discussions, participants identified eight individuals with schizophrenia and 13 with a psychotic mood disorder, confirmed through SCAN interview. Studies of psychotic disorders in such communities are likely to benefit from combining structured interviews with the key informant method.
Keywords: Borana community; Psychotic disorders; key informant method.