What are the risks?
• Overly -intense experiences, hard on the lungs to smoke, stomach discomfort, overwhelming fear, high blood pressure, paranoia.
• Effects when smoked increase radically if individuals ingest Monoamine oxidase inhibitors (MAOIs). These are some kinds of antidepressants, given by medical prescription. Their combined use is contra-indicated.
• The fast onset and great intensity of the trip could lead to problems with individuals, if not prepared (dropped pipe, knocking things over, falling). They should lie down, without standing. It is good not to be alone.
• They should not operate heavy machinery or drive when using DMT.
• Integrating the experience when smoking DMT could be hard for some individuals. It could lead to periods of increased anxiety, difficulty concentrating on everyday tasks, excessive absorption in thoughts of what has been experienced, sleeping problems and others. Generally these effects dissipate on their own over the course of a few days, but there have been reports of persisting problems.
• Individuals currently in the midst of emotional or psychological upheaval in their everyday lives should avoid using DMT as they can trigger even more serious problems.
• Individuals with a family history of schizophrenia or early onset mental illness should avoid DMT, because psychedelics have been known to trigger latent psychological and mental problems.
Source:
http://www.erowid.org/chemicals/dmt/dmt.shtml