"after trying multiple different antidepressants (such as, prozac and celexa) i was finally put on effexor. as far as it treating my depression and anxiety, it has helped enormously. but the side effects are unreal. even after a day of missing my 150mg dosage i will experience brain &quot;zaps&quot; or brain &quot;shivers&quot;. it is an annoying and scary sensation. i have experienced extreme drowsiness, and yet no weight gain."