MIXED-HANDEDNESS IN PATIENTS WITH FUNCTIONAL-PSYCHOSIS

Background. An excess of non-right-handedness has been shown among pat ients with schizophrenia. However it is not clear whether this finding can be accounted for by an increase in left-handedness, mixed-handedn ess or both. It is not known whether atypical patterns of hand prefere nces occur in other functional psychotic illnesses. Method. The Annett hand preference questionnaire was administered to patients with schiz ophrenia (n=120); affective psychosis (n=55); schizoaffective psychosi s (n=41), and control subjects (n=86). Handedness was classified into three categories: right, mixed and left-handedness. Results. The hand preference patterns of patients with functional psychotic illnesses we re not significantly different from controls. Patients with schizophre nia showed a non-significant excess of mixed-handedness compared with controls. Patients with schizophrenia and affective psychosis showed a non-significant decrease in left-handedness compared with controls. C onclusions. Although our results showed a trend in the hypothesised di rection, we failed to demonstrate that patients with psychotic illness differed from controls on self-reported hand preference patterns.