What are the potential long term effects on your cognition after abusing otc medications such as dxm and dph?

DXM could potentially cause Olney's lesions, however that hasn't been observed in humans or other primates.

DPH inhibits your ach receptors and from what I've read that is associated with cognitive decline.

Anyone wanna fill me in? I've used both of these in the past month and would like to try them again, but long term use I don't know. If I were to continue it would only be about 2 to 3 times a month