the antidepressants which will cause weight gain are ones with diazapines in them or antihistamines to control anxiety and help sleep. two that i have been on and gained weight are called (in the UK) dothiepin and mirtazapine.

i don't know exactly why you gain weight but your appetite increases and you become more lethargic - as for a chemical slowing down of the metabolism i don't know.

i found the effect similar to getting the munchies after smoking pot - desire for lots of high sugar/carb foods.


other antidepressants (generally SSRIs) caused no gain or loss for me.