Depressive retardation and treatment with fluoxetine: assessment of the motor component.

Changes in motor slowing between the start and end of treatment were studied in 22 inpatients with a Major Depressive Episode and 22 normal, healthy control persons. The degree and pattern of motor slowing were measured and analysed using computer-aided simple drawing tasks that did not require any higher order cognitive processing. The patients were treated with fluoxetine 20 mg/day for 6 weeks. Tests took place after 1 week (T0) and 6 weeks (T1). At T0 patients showed marked slowing, apparent in longer movement times and lower velocities than their controls. The differences between groups increased as the size of the movement increased or the accuracy demands increased. In all the trials, patients showed clear initiation difficulties. At T1 the motor slowing of the depressed patients had improved, but not disappeared. Significant differences remained between the two groups.