I'm familiar with SSRIs as I have taken them. It's unlikely SSRIs caused this, even if he was taking them and suddenly stopped, which can have some bad side effects. It's more likely he was taking prozac at a high dose, suddenly stopped, and went nuts and/or psychotic. Prozac is generally the drug of LAST choice because of it's potential side effects. There must be at least 5 other drugs people can take for depression first, like Zoloft, Wellbutrin (buproprion), and citalopram.  It just seems like some people have a really bad reaction when they take prozac, or suddenly stop it, especially people under age 18. There can also be interactions with other drugs. The pharmacist (because the prescribing doctors normally don't want to do this) is supposed to check for interactions of drugs which is why it's important your pharmacy has all the meds you are on, so you don't die.