Long term dangers of one-time or occasional use

Long term effects after one-time or occasional use are rare, but can occur, due to predispo- sition or traumatic experiences, for example.
Hallucinogenic Persistent Perception Dis- order (HPPD) – also known as flashbacks can occur even after one-time use. In most cases this disorder is very mild and not considered a problem. Symptoms can be anything from expe- riencing rare visual disturbances, similar to when under the influence, to severe cases where these disturbances persist almost permanently. Any hallucinogen (LSD, MDMA, Mescaline, DMT, Psilocybin, etc.) has the capacity to cause this disorder, but LSD seems to be the most common culprit. So far it is not clear what causes HPPD. HPPD in its severe form is very rare.

A condition similar to Post Traumatic Stress Disorder can result from a particularly bad or traumatic experience. To minimize the risk of such traumatic experiences, it is essential to be aware of your mind set before beginning a journey, as well as your surroundings.

There is a small percentage of the population that is susceptible to psychotic reactions or what is termed a schizophrenic break when ingesting entheogens. In general, it is thought that this occurs only if a predisposition towards schizophrenia already exists in the individual. Milder cases can show signs of delusions, paranoia, and messianic complexes. Again, paying attention to your mental state before beginning your journey
is essential to prevent this. If you have a history of mental illness related to psychosis or schizophrenia, entheogens in a non-therapeutic setting might not be the right choice for you.

Popular opinion suggests that using entheogens brings about significant personality changes. This is true to some extent: All experiences (entheogenic or not) alter your personality. This is not necessarily a bad thing, nor is it necessarily something drastic. In fact many people who use entheogens deliberately seek to improve their personality or their self in general through their use. In general, there is no difficulty adjusting and returning to the real world.