What Causes Psychosis?

Although psychosis can occur in several mental health and medical conditions, this article focuses on psychosis triggered by alcohol or other mood-altering substances. Substance use can either trigger a first episode of psychosis or worsen an existing vulnerability, particularly in people with underlying mental health conditions or a family history of psychotic illness. Although stimulant drugs and cannabis are well-known triggers, severe alcohol intoxication and alcohol withdrawal can also cause psychotic symptoms in some individuals.

Psychosis Vulnerability

A person who has experienced substance-induced psychosis is much more likely to experience further psychotic episodes if they use drugs or alcohol again. Using alcohol or drugs places additional stress on already vulnerable brain pathways, increasing the likelihood of another psychotic episode. Symptoms often return more quickly and may become more severe than before.

Risks and Effects

• Triggering new episodes: For people who have previously experienced substance-induced psychosis, returning to alcohol or drugs significantly increases the risk of another episode. In many cases, symptoms return more rapidly and may become more severe than before.
• Blocking medicine: Alcohol and other drugs can interfere with prescribed mental health medications, including antipsychotic medication, making them less effective.
• Higher chance of long-term illness: Continuing to use substances after a first episode raises the risk of developing a psychotic disorder.  

Can Psychosis Be Treated?

Some people experiencing severe substance-induced psychosis require stabilisation in a psychiatric hospital before entering addiction treatment. Once medically stable, comprehensive rehabilitation should address not only substance use but also the underlying psychological, emotional, and social factors that contribute to addiction. At Twin Rivers Recovery, we provide an individualised treatment programme that addresses trauma, co-occurring mental health conditions, substance dependence, and the development of healthier coping strategies to support long-term recovery.

A Message of Hope

Recovery from substance-induced psychosis is possible, and many people make a full recovery when they receive timely treatment, remain abstinent from alcohol and other mood-altering substances, and receive ongoing psychological support. Seeking help early can make a significant difference and offers the best chance of a successful recovery.

Frequently Asked Questions:

Can substance-induced psychosis go away? Yes. Many people recover completely with prompt medical treatment, abstinence from alcohol and drugs, and ongoing psychological support.

Can cannabis cause psychosis? Yes. In some people—particularly those with a genetic or mental health vulnerability—cannabis can trigger psychotic symptoms or worsen an existing condition.

Is substance-induced psychosis the same as schizophrenia? No. Although the symptoms can be similar, substance-induced psychosis is directly related to alcohol or drug use. However, repeated episodes may increase the risk of developing a long-term psychotic disorder in some individuals.

Disclaimer: This article is intended for educational purposes only and should not replace professional medical advice, diagnosis, or treatment. If you or someone you know is experiencing psychosis, particularly if they are at risk of harming themselves or others, seek immediate medical attention or contact your nearest emergency service.