That seems to happen to some people. The longer they use it the bigger the jerk they become. My theory is it triggers you to be on high alert all the time so

That seems to happen to some people. The longer they use it the bigger the jerk they become. My theory is it triggers you to be on high alert all the time so all the slights most people shrug off, do not get shrugged off and they slowly become a jerk. The downsides to many of these drugs is we have scant data on long term use because they are forbidden so the study of it is low. So we end up with a lot of anecdotal data (both for and against).