Was taking Lexapro and it made me tired and listless. Started Pristiq and I have been on it for 10 weeks. Felt good, better mood , more energy and just better over all. Noticed a slight weight gain. Now, I feel lethargic again and listless and not very motivated. Has anyone taken a anti-depressant that will lift my mood, moral, spirits and give me more energy without weight gain? None of the SSRI or SSNI have effected my sex drive or performance. Any suggestions would help.