Aims: Milnacipran, a new specific serotonin and norepinephrine re-uptake inhibitor, is as effective as tricyclic antidepressants. Symptomatological predictors of antidepressant response to milnacipran have not been studied until now.
Methods: This study included 101 Japanese patients who fulfilled the DSM-IV criteria for the diagnosis of major depressive disorders and whose score on the Montgomery and Åsberg Depression Rating Scale (MADRS) was ≥21. Eighty-three patients were finally included. Patients with a pretreatment MADRS score ≥31 points were defined as severe (n = 28), and the rest as non-severe (n = 55). The three-factor model of MADRS was used for analysis; the first factor was defined by three items, the second factor was defined by four items and the third factor was defined by three items representing dysphoria, retardation, and vegetative symptoms, respectively. Milnacipran was administered twice daily for 6 weeks. The initial dose was 50 mg/day; after a week it was increased to 100 mg/day.
Results: No significant difference was observed in the mean score of first factor, second factor and third factor at pretreatment time between responders and non-responders in both severe and non-severe patients.
Conclusions: No predictor of antidepressant response to milnacipran was obtained using the three-factor structures of the MADRS in Japanese patients with major depressive disorders.