I'm sorry that you're worrying about that You would get similar side effects, like sedation/akathisia, weight gain etc. They test drugs on healthy volunteers first to find out if they're safe for humans and what the side effect profile is, then they test it on those with the condition to see if it's actually effective in humans against a placebo. I don't think it has anything to do with the brain "using the AP" because the patient "needs" it. Many APs cause sedation in those who have been prescribed them for psychosis, and also in non-psychosis e.g. seroquel/quetiapine causes sedation as a side effect as an AP, but also causes it in those with BP using it as a mood stabiliser, and in those who take it as a sleep aid.

I don't know if this would happen for everyone who took an AP they didn't need. But I have felt 'trapped in a box' at times before (though I don't know what meds I was or wasn't on at each point) - personally I always thought it was dissociative due to anxiety. I felt like I was in a glass box where I could see out, but things weren't as clear as 'real life', and sounds were more muffled, and experiences didn't cause the emotions expected (I mostly felt numb) as everything around me that I was observing through my 'glass box' didn't feel real. I always referred to it as derealisation, but idk if that is what these other people mean when they say 'trapped in a box'. Other than that I've had the usual AP side effects - sedation, akathisia, increased appetite & weight gain, blurred vision (starting abilify/aripiprazole) & tinnitus (abruptly stopping aripirazole), and that's all I can think of for now.

*Willow*