Psychomotor retardation, a general slowing of activity which is one of the central characteristics of depression, was investigated by measuring reaction time and movement duration in drawing tasks. Twenty depressive patients and 20 normal controls participated in two tasks in which either simple or more complex figures had to be copied as fast as possible on a digitizer. In general, patients needed more time to complete the drawing tasks than controls, and they performed them differently. Six patients, who could be tested before and after treatment, showed changes in drawing speed that correlated with clinical improvement. These results suggest that psychomotor retardation might be fruitfully studied by measuring the kinematic aspects of drawing and might provide objective parameters to measure progress in therapy.