Although it is known that certain benzylpiperazine-aminopyridines or open chain forms thereof are effective in stimulating neural growth in in vitro tests, it has now been surprisingly found that administering these compounds in a dosage range of 10 mg/day-130 mg/day over 25-35 days is effective in treating Major Depressive Disorder (MDD) such that statistically significant results can be obtained with samples of only six subjects.