Dose-related biphasic effect of prolyl-leucyl-glycinamide (MIF-I) in depression

Five of 8 patients with unipolar or bipolar endogenous depressions taking prolyl-leucyl-glycinamide (MIF-I), 75 mg/day, showed substantial improvement within a few days of beginning treatment compared with similar improvement in only 1 of 10 receiving 750 mg/day of MIF-I and only 1 of 5 patients taking placebo. The lower dose of MIF-I was associated with significantly greater improvement than both the higher dose and placebo on all of the rating scales used. The authors suggest that an even lower dose of MIF-I, on the order of 0.1 mg/kg, may have a greater effect as an antidepressant.