This study investigated the point prevalence of extrapyramidal movement disorders in patients with chronic schizophrenia and related disorders who are currently treated by Northland District Health Board (DHB) mental health services, New Zealand. The study also investigated evidence of variation in the point prevalence of these disorders based on the ethnicity of the patients (indigenous Māori patients and non-Māori).

151 patients, who had received antipsychotic medication for 3 months or more, were recruited as participants for the study using randomised computer software. Ethnicity was documented using self-identification. Akathisia was assessed using the Barnes Akathisia Rating Scale (BARS). The Abnormal Involuntary Movement Scale (AIMS) was used to assess tardive dyskinesia and extrapyramidal side effects (EPSE) were assessed by the Simpson-Angus Rating Scale (SAS).

9.3 % had akathisia using Barnes scale, 43% had Parkinsonian symptoms on SAS scale, and 18.5 % had tardive dyskinesia using AIMS scale. The analysis failed to show any statistically significant differences based on ethnicity (indigenous Māori and non-Māori). P = 0.284, 0.176, and 0.201 for Barnes, SAS and Aims respectively.

The findings suggest that the prevalence of neuroleptics-induced movement disorders in psychotic patients within Northland DHB (9%-43%), is similar to the documented international figures. These findings also indicate that there is no significant difference based on ethnicity between Māori and non-Māori in terms of movement disorders profile.