The main aim of the present study was to explore the value of several measures of handwriting in the study of motor abnormalities in patients with bipolar or psychotic disorders. 54 adult participants with a schizophrenia spectrum disorder or bipolar disorder and 44 matched healthy controls, participated in the study. Participants were asked to copy a handwriting pattern consisting of four loops, with an inking pen on a digitizing tablet. We collected a number of classical, non-linear and geometrical measures of handwriting. The handwriting of patients was characterized by a significant decrease in velocity and acceleration and an increase in the length, disfluency and pressure with respect to controls. Concerning non-linear measures, we found significant differences between patients and controls in the Sample Entropy of velocity and pressure, Lempel-Ziv of velocity and pressure, and Higuchi Fractal Dimension of pressure. Finally, Lacunarity, a measure of geometrical heterogeneity, was significantly greater in handwriting patterns from patients than from controls. We did not find differences in any handwriting measure on function of the specific diagnosis or the antipsychotic dose. Results indicate that participants with a schizophrenia spectrum disorder or bipolar disorder exhibit significant motor impairments and that these impairments can be readily quantified using measures of handwriting movements. Besides, they suggest that motor abnormalities are a core feature of several mental disorders and they seem to be unrelated to the pharmacological treatment.

We explore the idea that cognitive demands of the handwriting would influence the degree of automaticity of the handwriting process, which in turn would affect the geometric parameters of texts. We compared the heterogeneity of handwritten texts in tasks with different cognitive demands; the heterogeneity of texts was analyzed with lacunarity, a measure of geometrical invariance. In Experiment 1, we asked participants to perform two tasks that varied in cognitive demands: transcription and exposition about an autobiographical episode. Lacunarity was significantly lower in transcription. In Experiment 2, we compared a veridical and a fictitious version of a personal event. Lacunarity was lower in veridical texts. We contend that differences in lacunarity of handwritten texts reveal the degree of automaticity in handwriting.

BackgroundAntipsychotic 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.ObjectiveIn 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.MethodSixty-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.ResultsROC 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.ConclusionsIn line with previous research, our results question the use of rating scales as the only measure in the evaluation of EPS symptoms.Disclosure of interestThe authors have not supplied their declaration of competing interest.