These are the dangers common to all psychedelic
When on a psychedelic drug, it is easier to accidentally injure yourself. Also because of the disorientating and potentially delusion inspiring nature of the experience, you could be lead to inflict harm on others or yourself. People have fallen off rooftops, run into traffic, attempted to throw people off rooftops as 'sacrifices', drowned, and so on. The best way of protecting against this is to have a friend with you who is sober to look after you and handle any negative situation that might arise.
A bad trip
is a negative psychedelic experience. It can range from a mildly negative feeling of anxiety/discomfort, to full-blown psychosis. Bad trips
usually ruin a psychedelic experience for the tripper and everyone else. Most bad trips are manageable, just very uncomfortable and difficult. Some are extreme and unmanageable though. It's not uncommon for a bad trip to result in lingering psychological issues. Usually just a few days of negative emotions and anxiety. Sometimes, however, a week or so of serious anxiety, destabilized mental state and impaired functioning is possible. On very rare occasions, a month or two of severely diminished functioning, traumatized mental state, depression & crippling anxiety can occur. More information on bad trips can be found here
. The best way of avoiding a bad trip is having the correct set and setting.
Psychedelics are believed by researchers not to cause permanent psychosis, however they could trigger a latent mental illness in someone who was already predisposed to it, or make existing mental illnesses worse. If there is a history of mental illness in your family, you are more likely to be predisposed. Everyone is at some risk, however.
PTSD, anxiety disorder, depression & depersonalization.
There are anecdotal reports of the trauma inflicted by some bad trips leading to depression and anxiety which while usually temporary, could potentially develop into lasting disorders. While no different to the potential of any traumatic event to cause lasting disorders, nonetheless this is a danger of psychedelic drug use.