Matiruku, a Fijian madness: an initial assessment.

In Fijian, matiruku means literally 'low tide in the morning' and figuratively somebody periodically insane. In this study, the conceptual basis of matiruku was examined by means of a questionnaire completed by 24 Fijians which explored its occurrence, aetiology and precipitation, phenomenology, management and prognosis. It was concluded that matiruku corresponds to hypomania, which may have special features in Fiji: short duration, frequent recurrence and an intensification of symptoms in the morning.