Prevalence of movement disorders in adolescent patients with schizophrenia and in relationship to predominantly atypical antipsychotic treatment.

Objective: To examine prevalence of movement disorders (MDs) such as tardive dyskinesia (TD), parkinsonism or akathisia in an adolescent population with schizophrenia and in relationship to predominantly atypical antipsychotic treatment.

Method: Ninety-three patients (aged 19.6+/-2.2 years) were ascertained in this cross-sectional/retrospective study. 76 patients (81.7%) received atypical, 10 (10.8%) typical antipsychotics and 7 (7.5%) combinations of atypical/typical antipsychotics. MD symptoms were assessed using Tardive Dyskinesia Rating Scale (TDRS), Abnormal Involuntary Movement Scale (AIMS), Extrapyramidal Symptom Scale (EPS), Barnes Akathisia Scale (BAS).

Results: Movement disorder symptoms were found in 37 patients (39.8%) fulfilling strict/subthreshold criteria for TD (5.4/11.8%), parkinsonism (2.2/25.8%) or akathisia (1.1/11.8%), respectively. Patients treated with typical antipsychotics displayed a significantly higher EPS-score (P=0.036) and a tendency towards a higher BAS-score (P=0.061) compared to patients with atypical antipsychotics. Treatment durations with typical/atypical antipsychotics showed trends towards advantages of atypical antipsychotics with regard to parkinsonism/akathisia symptoms (P=0.061; P=0.054), but not with regard to TD symptoms (P=0.003), possibly due to confounding effects.

Conclusion: Under treatment with atypical antipsychotics MD symptoms are less prevalent and less pronounced than under typical antipsychotics. We speculate that the finding of relatively high prevalence rates of subthreshold MD symptoms may be, at least partially, explained by previous or combined therapy with typical antipsychotics.