As with any other psychotic conditions, the primary symptoms of Substance/Medication-Induced Psychotic Disorder are hallucinations and delusions that are more severe than what may be considered routine symptoms of intoxication or withdrawal. Signs of psychosis include:

• unusual and suspicious beliefs
• delusions of persecution that are unlikely to be true, such as "people are out to get me" or "people are spying on me"
• hallucinations, or hearing or seeing things that aren't actually there

These symptoms are often accompanied by other physical and psychological symptoms. These may include:

• insomnia
• aggressive behavior
• agitation
• mood swings, typically ranging from euphoria to deep fear
• suicidal thoughts

Symptoms of Substance/Medication-Induced Psychotic Disorder are generally acute, lasting only until the substance or medication is cleared from the body. In some cases, however, depending on the type of substance or medication involved, psychotic symptoms may continue for up to several weeks.

Substance/Medication-Induced Psychotic Disorder can occur with the use of, or during withdrawal from, alcohol, recreational drugs, and even prescription medications such as opioids and sedatives/hypnotics. Other substances that can trigger a psychotic event include cocaine, amphetamines, phencyclidine (PCP), and alcohol. Psychosis that results from the use of amphetamines, PCP, or cocaine may last for several weeks. More than half of methamphetamine users have experienced short- or long-term psychosis. Studies have found that chronic use of cannabis can also induce psychosis in some people.

Substance/medication-induced psychosis incidents are often seen in hospital emergency rooms and mental health crisis intervention centers. Since patients with mental health disorders can also have medication overuse or substance abuse problems, the physician must first determine if psychotic symptoms are due to a condition such as schizophrenia or to the substance itself.

Antipsychotic or anti-anxiety medication, such as benzodiazepine, is often administered to reduce symptoms, especially in the case of psychosis due to amphetamines or other dopamine-stimulating drugs. Depending on the type of substance that triggered the psychotic event, treatment may simply consist of monitoring the patient in a calm, quiet environment. The outcome is generally worse for those with psychotic mental health disorders who also experience substance-induced psychosis.