Antipsychotic drugs are effective in schizophrenic disorders, but they are also used to treat other psychiatric conditions. Typical antipsychotics cause important extrapyramidal symptoms (EPS), which frequently result in non-compliance with antipsychotic medication. It has been stated that the second-generation antipsychotics (atypical) provoke EPS side effects less frequently than typical antipsychotics. However, there is some controversy around this statement, especially because of inefficient measures of EPS. Clinical assess of EPS normally relies upon observer-based ratings, but their reliability and validity has not been consistently established.

In the present work, we have explored the convergent and discriminant validity of the Abnormal Involuntary Movement Scale (AIMS) and the Simpson-Angus Scale (SEE), in a Spanish sample of patients with severe mental disorders. Patients could be under typical or atypical antipsychotics, antidepressants, benzodiacepines, or a combination of these.

Sixty-one patients with severe mental disorders from the Mental Health Day Hospital of St. Agustín (Linares, Spain) participated in the study. Inclusion criteria were DSM-V diagnosis of schizophrenia or schizophrenic disorder, bipolar, or borderline personality disorders, and age between 18-61. In order to explore the discrimination capacity of each rating scale, Receiver Operator Characteristic (ROC) analyses were conducted.

ROC curves indicated a suitable construct validity of the scales in the measurement of drug-induced motor symptoms. However, the scales were not sensitive to the number of years under treatment.

In line with previous research, our results question the use of rating scales as the only measure in the evaluation of EPS symptoms.

The authors have not supplied their declaration of competing interest.