Effects of fluoxetine on fine motor performance in dysthymia: An 8-week, nonrandomized, open-label study

Background: Present findings on psychomotor retardation in dysthymia are inconsistent and changes in psychomotor performance during antidepressant treatment have not been investigated in this population to date.Objective: The present study aims to explore the psychomotor effects of an 8-week regimen of fluoxetine in dysthymic patients.Methods: Dysthymic patients (both inpatients and outpatients of the Psychiatric Hospital Sint-Norbertus, Duffel, Belgium), presenting over a period of 2 years, meeting the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria for dysthymia, and having Hamilton Depression Rating Scale scores of ≥ 12 were enrolled. During 8 weeks of treatment with fluoxetine 20 mg/d, depression severity and graphic motor activity were assessed 4 times by recording the time (a reaction time [RT] and a movement time [MT]) participants needed to copy single lines and simple and complex figures. The patients' outcomes were compared with those of untreated, healthy controls, matched for sex and comparable age and education. The assessors were masked to treatment and group.Results: Eighteen dysthymic patients (mean age, 40 years; male/female ratio, 4/14; mean weight, 70 kg; all white) were treated; 18 healthy controls (mean age, 40 years; male/female ratio, 4/14; mean weight, 72 kg; all white) were used as comparison. The overall patient group experienced significant psychomotor changes only in association with the complex figure-copying task (RT: F = 5.67, P < 0.05). In a subgroup analysis of 9 patients who clinically responded to treatment (ie, > 40% decrease in severity scores), significant improvements were observed only for the RT of the line- (F = 4.75, P < 0.05) and complex figure-copying task (F = 11.86, P < 0.01) and the MT of the simple figure-copying task (F = 7.57, P < 0.05), but not for the other psychomotor variables.Conclusion: Although some significant psychomotor changes were observed in a subgroup of clinically responsive dysthymic patients, the overall results of this small, nonrandomized, open-label study do not suggest a beneficial psychomotor effect associated with short-term fluoxetine treatment of dysthymia.