Episodes of substance-induced psychosis are common in emergency departments and crisis centers. Many substances may bring on these episodes, including alcohol, amphetamines, cannabis, cocaine, hallucinogens, opioids, phencyclidine (PCP), and sedatives. To be considered substance-induced psychosis, the hallucinations and delusions should be greater than those that typically accompany simple substance intoxication or withdrawal, although the person may also be intoxicated or withdrawing.
Symptoms are often brief and disappear once the drug that is causing the symptoms is cleared from the body, but psychosis triggered by amphetamines, cocaine, or PCP may last for many weeks.
In most substance-induced psychoses, stopping the substance and taking an antianxiety or antipsychotic drug is effective.
For psychosis due to drugs such as LSD (which stands for lysergic diethylamide), quiet observation may be all that is needed.