Chat with us, powered by LiveChat

Understanding the Link Between Schizophrenia and Addiction

Schizophrenia is a serious mental illness involving psychosis, distorted thoughts, and behaviors. It is classified as a disability, impacting more than 20 million people worldwide, per the World Health Organization (WHO).

The journal Administrative Policy in Mental Health reports on studies indicating that close to half of those diagnosed with schizophrenia will also struggle with addiction at some point in their lives.

A Close Link

There is a close link between schizophrenia and drug abuse. Drug use can exacerbate the symptoms of schizophrenia as well as complicate treatment for the disorder.


Abusing drugs can also induce psychosis and trigger a relapse of schizophrenia. It can potentially even speed up the onset of schizophrenia for people who are already at risk for the disorder.

There are several overlapping factors that connect schizophrenia, drug use, and addiction.

  • Genetics
  • Brain chemistry
  • Environmental factors
  • Family history

Co-occurring schizophrenia and addiction require specialized and integrated treatment methods that will often include therapeutic, pharmacological, and supportive approaches. Both schizophrenia and addiction are treatable disorders.

Schizophrenia and Drug Use: Overlapping Risk Factors

Between 10 and 70 percent of people battling schizophrenia also abuse drugs and/or alcohol, and a half struggle with substance dependence, the journal Dialogues in Clinical Neurosciences publishes. There can be several causal reasons for this.

Schizophrenia is a mental illness that is more common in men than in women. The onset of the disorder typically happens between ages 16 and 30, the National Institute of Mental Health (NIMH) explains.

Similarly, men are more prone to substance abuse and addiction than women, and young adults between the ages of 18 and 25 comprise the most significant demographic for drug use and addiction as well, per the National Survey on Drug Use and Health (NSDUH).

Both schizophrenia and addiction have a genetic connection. A person with a family history of either disorder is at a bigger risk for developing either one.

alcohol pyschosis

Role of Biology and Environment

Biological factors, including brain chemistry, formation, and function, can also be involved in the onset of both addiction and schizophrenia. It may explain some of the overlap.

Both addiction and schizophrenia may be caused by an imbalance of neurotransmitters and dysfunction in the brain. Low levels of dopamine or serotonin in the brain can cause a person to want to take mind-altering drugs that increase these pleasure-inducing neurotransmitters, for example.

Therefore, someone struggling with schizophrenia may use drugs or alcohol as a method of self-medicating — in an attempt to feel better or regulate moods or emotions. This can only end up complicating and elevating schizophrenia symptoms. It can often lead more rapidly to addiction as well.

High levels of stress are considered a risk factor for both addiction and schizophrenia. Elevated stress impacts brain chemistry. It can, therefore, raise the rate of dysfunction in the brain and the odds for abusing drugs as a possible outlet or escape.

Schizophrenia and drug use are complexly intertwined. Someone battling schizophrenia who also abuses drugs is at a higher risk for addiction than someone without a co-occurring mental health disorder.

Drug Use and the Elevated Risk for Schizophrenia

Medical News Today published studies showing an elevated risk for developing schizophrenia when abusing drugs, such as cannabis, alcohol, hallucinogenic drugs, sedatives, amphetamines, or other substances.

The causal link between drug use and schizophrenia is unclear, although the National Health Service (NHS) reports that individuals who use marijuana before the age of 15 quadruple their risk for developing schizophrenia by age 26. Drug use at a young age can influence brain chemistry and increases the risk of addiction.

The National Institute on Drug Abuse (NIDA) explains that drug abuse, particularly cannabis use, may increase the odds for developing psychosis and schizophrenia in individuals who are already genetically vulnerable to the disorder.

While drug use can induce psychosis, it will likely only cause schizophrenia to occur in people who are already genetically susceptible to the disorder. Using drugs in adolescence may speed up the timetable for when schizophrenia symptoms will start in someone with a genetic and/or biological risk for the disorder.

Drug use can also trigger a relapse or return of psychotic symptoms in someone with schizophrenia who have not been experiencing symptoms or who has had them under control for a period of time through treatment.

Treating Co-Occurring Schizophrenia and Addiction

Schizophrenia and addiction are both chronic diseases with far-reaching social, emotional, and physical consequences. When combined, the harms associated with both disorders are amplified.

Specialized treatments for both disorders include:

  • Medications such as antipsychotics
  • Behavioral therapies
  • Counseling, both group and individual
  • Life skills training, including learning coping skills
  • Education to learn more about how to manage both disorders
  • Supportive care

Co-occurring disorders are optimally treated through integrated care models that can address both disorders simultaneously and continuously.

Since schizophrenia symptoms can be significant and particularly disabling, residential or inpatient treatment methods are often best, especially when drug use and addiction are also involved.

Treatment for co-occurring schizophrenia and addiction will need to be highly specialized. The severity of both disorders will dictate the level of care, but when addiction and schizophrenia occur together, the intensity of both will be heightened and complicated.

Detox is often the starting point for treating co-occurring disorders. Medical detox programs are ideal, as they can provide the highest level of care and safety.

Medications will need to be closely monitored in someone with a history of drug abuse and addiction.

Individuals may move between different levels of care as treatment progresses, with regular assessments to determine what is ideal for the person’s current status.

Unique Risks

Schizophrenia is a mental illness that is indicated by hallucinations, delusions, distorted thoughts, movement disorders, problems regulating moods, and cognitive issues. All these side effects can be exacerbated by substance abuse.

While drugs and alcohol can temporarily improve a person’s emotional state, the comedown can be magnified in someone battling a mental health disorder such as schizophrenia. Drugs and alcohol can also induce greater psychotic symptoms.

Drug withdrawal is intensified when someone also struggles with schizophrenia. Increased depression, anxiety, and suicidal thoughts and actions need to be closely monitored during detox and treatment.

When schizophrenia and addiction co-occur, the threat of illness, poorer treatment outcomes, and treatment compliance are heightened.