Permastoned, this isn't really with tabs but relates to tripping. I have never felt crazily out of control on psychedelics even on some fairly high doses and although I have believed some weird stupid shit, still had the sense to not follow through.
A close friend of mine while tripping on mushrooms decided he must stop littering, and he actually did for about 3 or 4 months but eventually went back to it.
Another friend of mine on our second mushroom trip (we started picking together) at one point wrapped himself in a blanket and was lying on the floor babbling all kinds of incoherent shit in a strange voice akin to that of a little girl of arab descent for about 20 minutes, he then got up and ran through the house questioning who and where he was.
Tripping can most certainly fuck some people over but others are fine. Someone very close to me attempted suicide less than a week before I ate my first (and to date only) acid trip, and although I had thought about it alot in the lead up (I know this was a BAD idea but i only had one tab and Ididn't want to waste it by letting it degrade and I could never get them before that and can't now) I can say I didn't think about that once while I was tripping.
The only difficulties I experienced from tripping came from frequent heavy use (near daily use of mushrooms, I had 1000,s of subs, I'm sure you can imagine) in which I started to become deluded about what reality was and believed every single person I knew had some very strange agenda to keep me from "the truth" I was very paranoid, reclusive and emotional, I also had permanent tracers and walls breathing and shit for I don't know how long after some hallucinations reccur to this day.
Majority of psych users on BL get into this whole self improvement, mind expansion thing, but generally most people I know have only ever viewed psychs as a fun way to get fucked up and most had no problems.
Sorry for the long post but to sum it up, theres no real way to guage how trips will affect you or predict what personality changes (permanent or temporary) will take place or even if they will. However I think most people who come to BL looking for info will be straight because they took the time to do research and are knowledgable enough to be able to firmly remind themselves its simply a drug.