The impact of tricyclic antidepressants and selective serotonin re-uptake inhibitors on handwriting movements of patients with depression

Psychomotor retardation is a common symptom of patients with major depression. While a variety of examinations using different techniques have been undertaken to assess the motor component of psychomotor retardation in depression, the effects of antidepressants on psychomotor functions have been examined less extensively. The aim of the study was to examine the effect of various pharmacological treatments on handwriting movements of patients with depression using a digitising tablet. Kinematic data of automated handwriting movements of depressed patients receiving tricyclic antidepressants (TCAs), patients on selective serotonin re-uptake inhibitors (SSRIs) and healthy subjects was analysed. Subjects were asked to perform a simple writing task. Statistical analysis revealed motor slowing in patients receiving TCAs. In comparison to both healthy subjects and patients receiving SSRIs, the TCA group displayed an increased movement time, reduced automation of handwriting, lower maximum velocities and reduced acceleration of descending strokes. The results suggest either that TCAs have adverse effects on motor functioning or that they are less effective in the treatment of motor retardation than SSRIs.