How does venlafaxine produce its antidepressant effect?

Venlafaxine is believed to produce its antidepressant effect by enhancing neurotransmitter activity in the central nervous system; preclinical studies show that venlafaxine and its major metabolite, O-desmethylvenlafaxine, inhibit serotonin and norepinephrine reuptake, while venlafaxine also weakly inhibits dopamine uptake.