I was on lexapro 20mg for 8 months and my pysc changed me last week(as the lexapro was'nt working for me)so i'm taking 10mg of prozac for 1 week then 20mg the next two weeks,this is the fifth day. I'm just enquiring if i'm suffering withdrawels from coming off the lexapro and straight onto prozac,I know 10mg prozac is'nt very effective but i feel so down today especially and very irritated,i'm snapping the head off everyone and bascially my head is all over the place,is this nornal?I know it takes time for new meds to kick in but just wondered is it wd's or side effects im experiencing and how long will it last?