A good friend had to take it off and on for months at a time for his Crohn's disease and it caused increased hunger/weight gain and "moon" face for him, acne and other skin conditions were his biggest negatives. I haven't thought about the psychiatric effects it may have had, he tends to be paranoid and argumentative even naturally but it did add depression I think; he was seeing a psychiatrist but had a lot wrong with his life too so I don't know where the line was. I've only taken it a couple times, for 3-5 days at a time for my asthma and don't recall any symptoms at all other than feeling loads better. I don't know if you'll be "allowed" to stay on it full-time/forever, it can seriously mess with organs and stuff so I think usually it is an off and on sort of thing, only using it when it is pretty much life-saving rather than just for pain.