more sci-fi ideas fer ya. take 'em, use 'em.
the character is being experimented on covertly. you, the author can form the story but here
is an interesting way for the villains to attempt mind control over the victim.
for instance, drugs put into medications the victim takes for varied health issues by prescription. anything from providing an extraordinary antidepressant effect to actually audient recived instructions like "do not interfere with others business", also, these mind control chemicals may make the victim repeat such mantras to him/herself as "i want to conform, i want to obey" and havev the effect of breaking the will of the victim or even seeking the result of reformatting the personality.
another mind control designed drug may make the victim hear noises have audient hallucinations, where there were none, and even affect the heart with chest pains or other health issues made to wear the target down.
perhaps make them two different pills.
make the victim smart enough to stop taking these corrupt medications in incriments, so as to test if the reactions they are having is reality or a drug related reaction.
it may assist to have agents or whoever the villains are in your story to 'foreshadow' the victim with "he/she hears voices" behind thier backs at any given location long before the corrupt medication is given.
remember, a tactic in covert operations is foreshadowing so the victim falls into circumstances set up by the villians and no one outside really questions which came first. the true reality of the victims circumstances or a set up.
I am trusting you authors out there to take my ideas and use them. i will not get a chance to, and i wanted to be a writer, among other pursuits...hey, 3 week grueling vocational tests dont lie. it was in my top four career choices.
hmm, so was detective or policeman. think i should go for it ? naaah, too much corruption.
good luck and help my babies live.