there was an awesome atlantic article around the early 2000's on the topic, the secret service at one point lost a large black bag carrying all the barbituates, painkillers, and dextroamphetamine he was being prescribed basically to such excess that they mobilized hundreds of extra agents from the service and the other trusted agencies to find the fucking thing.

the revelation in the piece is that during the bay of pigs, jfk was so fucked up on his medicine they basically shut him down because he was nonsensical to defense department and cabinet around him. he was asleep for a decent chunk of the most intense part of the crisis.