Mental illnesses are the primary risk for Salvia users. Hallucinogens have been known to cause severe depression or even schizophrenia. Considering the strength of the drug, taking too much at one time is a major hazard for users.
Flashbacks, or hallucinogen persisting perception disorder, can also occur because of Salvia abuse. A flashback is when a user re-experiences the hallucinations long after having taken the drug. These flashbacks can occur without any warning weeks or even months after using Salvia, and they can be just as horrific.