mental problems

they may be using it as an excuse but they also might not know exactly how they feel and may appear differently than what they feel.. they may also be talking and taking their info from the times where they were at their worst.. or they could just be trying to overly prove their point that there is something wrong with them because they dont think people believe them

I think some people do use it as an excuse and too many people stay on medication for too long and then become dependant on it instead of trying to make the effort to get off of it.

This is the tendency with these people to behave differently intentionally as they know no body will believe that they doing it intentionally because they know about their conditions. Virtually they take advantage of their being mentally sick.