Hand-Motor Dysfunction in Depression: Characteristics and Pharmacological Effects

Abstract

Motor retardation is a relevant aspect of depression. Kinematic analysis of movements can be applied to explore which type of motor dysfunction is associated with depression and to examine motor side effects of antidepressants. Using this tool, we aimed to investigate fine motor performance in patients suffering from depression and to compare a selective noradrenaline re-uptake inhibitor (NARI) (reboxetine) and a selective serotonin reuptake inhibitor (SSRI) (citalopram) regarding motor side effects after 4 weeks of treatment. In the first study (I), we examined 37 depressed patients and 37 healthy subjects using a digitizing graphic tablet and kinematic analysis of handwriting and rapid drawing movements. Both groups were comparable regarding age, gender distribution, handedness (preponderance of right-handers) and educational level. In the second study (II), we examined different types of hand movements in 16 depressed patients receiving citalopram (flexible dosage) and 12 depressed patients treated with reboxetine (varying dosage) using the afore-mentioned methods. Both groups were comparable regarding age, gender, handedness and the baseline Hamilton Depression Rating Scale total score. I: Depressed patients performed drawing with significantly less regular velocity than controls (p < 0.001), but normal velocity. Handwriting of depressed patients was abnormally slow (p = 0.04). II: Reboxetine led to a significant improvement of repetitive drawing movements in depression. In contrast, citalopram had no pronounced effects on hand movements in depressed patients. I: Irregular patterns of velocity peaks in depressed patients point to basal ganglia dysfunction and/or deficient activity of the sensorimotor cortex and the supplementary motor area as possible substrates of hand-motor disturbances in depression. II: Computer-aided analysis of hand movements is a sensitive tool for the registration of differential pharmaceutical effects on hand-motor function in depression.