What neurotic said...
To give an idea, I experienced from a second person view this year these dangers and by that i mean that me an one of my roommates purchased a couple grams at one point and experimented with it on several \occasions, him more than I and it was great for a while- I even had one of my strongest and most profound trips from it. But, after maybe a month or so of this, my roommate began to act strangely and this continued to get worse and worse ultimately evolving to the point of schizzoaffective symptoms and behavior. He would whip out his knife randomly and put it to his neck (not while tripping on it mind you, but while sober/stoned) and say outlandish and scary things, even threatening to kill me and then himself at one point. I ha to go around the house and hide all the knives and call his parents to bring him to a mental hospital, and while he has recovered a lot, hes still not the same.
Now some other things need to be considered here such as family history of psychosis, a difficult relationship with his girlfriend at the time, and extreme stress from school as well as a crappy living enviornment in general, so you add that all up and its hard to directly blame DMT but it certainly didn't help...However, a few weeks after this happened and I had been talking to a couple friends about it one friend told me a similar story about someone he knew who had been using DMT so theres a lot of correlation,
I can tell you this though--Ive done it, experienced it to the fullest and come back fine, and so have many people I know, but pretty much everytime Ive done it (and I know drugs obviously dont have a mind) but it seemed as if the drug was telling me it didnt want to be done if that makes any sense. If youre interested in DMT just tread lightly and dont be a hard-head or you may put yourself in a ward. Also it may be worth checking your family pedigree to see iftheres anyone in your family history with schizophrenia or any similar disorder. These dont nesccesarily get passed down, and there are epigentic factors that can both cause or inhibit the onset of schizophrenia, but if you have any sort of family history of psychosis, I strongly recommend staying away. DMT was cool, and Ive had my fill for my lifetime, but after seeing what it can do to those few people who just have psychological allergies to things as powerful as DMT, I don't think I'll ever go back and to be totally honest if theres any hesitation or darkness in your mind at the time, that 5-10minute trip really isnt worth the slight chance of slipping forever.