Predictors of abnormal involuntary movement in an african schizophrenia population.

As little is known about the risk factors for abnormal involuntary movements in African patients with schizophrenia, 170 Xhosa participants with schizophrenia were rated with the abnormal involuntary movement scale. Abnormal involuntary movements occurred in 19.4% of this group. Modeling of the data set showed that combining age at interview, age-squared, cannabis use or abuse, and anhedonia successfully identified 82.35% of cases of involuntary movements overall. Abnormal involuntary movements increased with increasing age (in a nonlinear manner), the presence of a cannabis use or abuse history seems to be protective against involuntary movements, and anhedonia is associated with the group that displayed fewer involuntary movements.