The invention relates to the compounds of formula I or its pharmaceutical acceptable salts, as well as polymorphs, solvates, enantiomers, stereoisomers and hydrates thereof. The pharmaceutical compositions comprising an effective amount of compounds of formula I, and methods for treating or preventing depression may be formulated for oral, buccal, rectal, topical, transdermal, transmucosal, intravenous, parenteral administration, syrup, or injection. Such compositions may be used to treatment of major depressive disorder (MDD), anxiety, neurological diseases, general anxiety disorder, social phobia, panic disorder, vasomotor symptoms, diabetic neuropathy, epilepsy, bipolar disorder, migraine, schizophrenia, cancer, menopause, HIV and familial adenomatous polyposis.