I have a theory that I just came up with a moment ago.

I think that the medication can potentially hurt short term memory. HOWEVER, I believe that long-term memory can stay mostly intact as long as you constantly stay engaged with material that makes you think. I think that one of the side effects of taking medication is losing interest in doing things. The "flat" affect. There is also usually some 'helplessness' mindset that seems to be perpetuated by the people who are trying to help us. (Doctors, social workers etc...) But basically my line of thought is that the medication can make someone disinterested and unwilling to learn so they don't spend time doing so. Which means your brain mass would eventually shrink because you're not strengthening the connections between the neurons.....

o_O I feel like I got a stroke of genius but I don't know if it makes sense...