It is known, though, that use over an extended period of time can lead to persistent speech problems, depression, anxiety, or memory loss. Some users may experience flashbacks in which a sensation or hallucination may recur days, weeks, or months after the drug has been taken. Anxiety and withdrawal from social situations may also occur. Users develop a condition similar to schizophrenia. As well, users can become aggressive, violent, paranoid, and delusional.
Users can also have auditory hallucinations.
Tolerance and Dependence Tolerance is the body adapting to the presence of a drug. When tolerance to a drug increases, more of the drug is necessary to achieve the same effect. Some people who use PCP become dependent on it. Compulsive daily use and strong craving for the drug are not unusual. The effects of PCP are extremely unpredictable.