Drug-Induced Psychosis: Symptoms, Diagnosis, Causes & Treatment

Drug-induced psychosis is a condition in which a substance or medication causes psychotic symptoms, particularly hallucinations or delusions. It is more formally known as substance- or medication-induced psychotic disorder and can develop during substance use, intoxication, withdrawal or after exposure to certain medications.

Symptoms can include seeing or hearing things that are not there, strongly believing things that are not true, paranoia, confused or disorganized thinking, and difficulty telling what is real. Although symptoms may improve after the substance is stopped, some people require treatment and continued monitoring because a psychotic episode can sometimes be followed by a schizophrenia-spectrum or other psychiatric disorder.

Treatment depends on the substance involved, the severity of symptoms and the person's overall mental health. Medical evaluation is especially important when psychosis causes severe agitation, confusion, inability to care for basic needs, suicidal thoughts or thoughts of harming another person.

Main symptoms

Drug-induced psychosis can affect perception, thoughts, behavior and the ability to recognize what is real. Common symptoms include:

• Hallucinations, such as hearing or seeing things that are not present

• Delusions, which are strongly held beliefs that are not based in reality

• Paranoia or intense distrust of other people

• Disorganized or incoherent speech

• Disorganized or unusual behavior

• Difficulty concentrating

• Memory problems and confusion

• Difficulty distinguishing reality from things that are not real

• Fear, panic or severe suspiciousness

The exact symptoms can vary depending on the substance or medication involved, the amount used and individual factors.

Possible causes

Drug-induced psychosis can be caused by:

1. Cannabis

Cannabis, particularly products containing THC, can alter thinking and perception. Hallucinations, fear, distrust, panic and temporary psychotic episodes are more likely with larger amounts, higher-potency products or in people with less experience using cannabis.

Cannabis-associated psychosis is also important because studies have found a relatively high rate of later schizophrenia among people diagnosed with substance-induced psychosis related to cannabis. However, factors such as genetics, environment and existing mental health conditions can also influence this relationship.

2. Amphetamines and other stimulants

Amphetamine use and amphetamine use disorder are associated with a higher risk of psychosis. Stimulant-related episodes may involve hallucinations, delusions, paranoia and other major changes in thinking or behavior.

The available evidence does not mean that everyone who uses an amphetamine will develop psychosis. Risk varies according to patterns of use and other individual factors.

3. Cocaine and other psychoactive substances

Cocaine can cause substance-induced psychotic symptoms, particularly during periods of intoxication or heavy use. Other substances associated with psychosis include hallucinogens, synthetic cannabinoids, ketamine, PCP-type substances and newer psychoactive drugs.

The type and severity of symptoms can differ between substances. Clinical evaluation is important because similar symptoms may also occur with an underlying psychiatric disorder.

4. Prescription medications

Psychosis can also occur as an adverse effect of certain medicines. Medications reported in association with psychotic symptoms include corticosteroids, antiepileptic medicines, antimalarial drugs and some antiretroviral medicines.

Persecutory delusions and auditory hallucinations are among the symptoms that may occur with medication-induced psychosis. Determining whether a medication is responsible requires careful review of when treatment was started, when symptoms appeared and whether another condition could explain the symptoms.

Confirmign a diagnosis

Diagnosis is based on a detailed clinical assessment. Doctors consider whether hallucinations and/or delusions developed during or soon after substance use, intoxication, withdrawal or exposure to a medication that is capable of causing these symptoms. They may also assess the type of substance, amount used, frequency of use and the effects it has had on daily functioning.

An important part of diagnosis is determining whether the psychosis is better explained by a primary psychiatric disorder, such as a schizophrenia-spectrum condition. Previous psychotic symptoms, a family history of psychosis, symptoms that were present before substance use or symptoms that continue during a sustained period without the substance can lead doctors to investigate other causes.

Timing alone does not always prove that a substance caused the psychosis. For this reason, follow-up may be necessary even when symptoms first appeared shortly after drug or medication exposure.

Treatment options

Treatment for drug-induced psychosis is individualized according to the substance involved, current symptoms and whether there is an accompanying substance use or mental health disorder. It may involve:

1. Stopping or changing the triggering substance

Avoiding further exposure to the substance that triggered psychosis is an important part of treatment. When a prescription medicine may be responsible, decisions about stopping, reducing or changing the medication should be made by a healthcare professional rather than independently.

Medical supervision can be especially important when withdrawal itself may cause symptoms or when the medication is being used to treat another health condition.

2, Antipsychotic medication

Antipsychotic medicines may be used to control acute psychotic symptoms. Studies of amphetamine-induced psychosis have found that several antipsychotics can reduce symptoms, although no single medication has been shown to be clearly superior in all cases.

The choice of medication and length of treatment depend on the clinical situation and should be determined by a healthcare professional.

3, Mental health and substance use treatment

When psychosis occurs together with a substance use disorder, treatment may involve coordinated care for both conditions. This can include psychotherapy, medication management, education for family members and specialized programs that address mental health and substance use at the same time.

People experiencing a first episode of psychosis may benefit from continued follow-up because the initial episode may not always remain an isolated event.

Possible long-term risks

Drug-induced psychosis can resolve, but some people later develop a primary psychiatric disorder. A systematic review involving more than 34,000 people with substance-induced psychosis found that about 25% were later diagnosed with schizophrenia, although the risk differed considerably according to the substance involved.

Another large study found that younger age, repeated emergency admissions, cannabis-induced psychosis and psychosis involving multiple substances were associated with a greater risk of later schizophrenia-spectrum disorders in some groups. These statistics describe populations and cannot predict what will happen to an individual person.

Persistent symptoms during abstinence therefore require further evaluation rather than being automatically attributed to previous substance use.

When to seek medical help

Medical assessment is recommended whenever hallucinations, delusions or other major changes in perception or behavior appear after substance use, withdrawal or starting a medication. Evaluation is also important when symptoms continue after the suspected substance is no longer being used.

Emergency medical care may be necessary when psychosis is accompanied by severe agitation, marked confusion, inability to care for basic needs, suicidal thoughts or thoughts of harming another person.