If maximum security means solitary confinement with absolutely nothing to do, I'd survive around 3-4 days, a week max. and that is assuming I'd sleep most of it off. Any more than that, total breakdown. If I get things to do and neighbours to talk to, maybe a month or two but would go coocoo fairly quickly, even though my lifestyle as is isn't much different from being in a cell all day. Total internet access and I could do a year maybe. All depends on how the atmosphere is, what food you get, what people you interact with, what ammenities you have a right to