Schizophrenia and substance use are closely associated, both potentially affecting one another in different ways.

People living with a mental health condition such as schizophrenia may turn to substances as a way to cope with what they’re experiencing.

But substance use and misuse can be a double-edged sword, both complicating the symptoms of schizophrenia and potentially increasing the chances you may experience or worsen symptoms.

Schizophrenia is a mental health condition affecting less than 1% of the population, according to the American Psychiatric Association.

The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) classifies schizophrenia as a psychotic disorder with symptoms that can include hallucinations, delusions, disorganized thinking, and negative symptoms (symptoms indicating a loss of ability).

Substance use disorder — a condition stemming from the recurrent misuse of alcohol or other substances — is prevalent among people living with schizophrenia.

A 2018 review found that 42% of people living with schizophrenia were also living with substance use disorder.

Of those, substance use was higher among males (48%) than females (22%) and was associated with an earlier onset of schizophrenia symptoms.

Drug-induced schizophrenia, the formal diagnosis listed by the DSM-5, is a bit of a misnomer.

Drug use or misuse doesn’t cause schizophrenia, but it may be the catalyst if you’re predisposed to the condition or are already experiencing mild symptoms.

Drug-induced psychosis is almost identical in symptoms to schizophrenia and the two may be confused for one another.

In drug-induced psychosis, psychotic symptoms are directly related to a drug use event. Once the substance is out of your system, hallucinations, delusions, or other symptoms of psychosis tend to resolve.

With schizophrenia, symptoms remain even after a substance has cleared your system. Schizophrenia is a lifelong condition even though symptoms may not always appear active.

Any substance can be misused. You can even misuse something generally considered “good for you” such as vitamins or supplements.

When it comes to schizophrenia and substance use, several substances top the list when it comes to misuse.

Illegal drugs

Illegal drugs, aka “street drugs,” are substances that are illegal for sale or possession in the United States.

This list includes substances such as:

  • heroin
  • cocaine
  • methamphetamine
  • LSD
  • hallucinogenic mushrooms
  • ecstasy (aka MDMA)

A 2010 qualitative study found that the five main reasons people living with schizophrenia might turn to street drug use include:

  • the feeling of skill, knowledge, and identity that comes with illegal drug use
  • the feeling of belonging within a group of peers
  • to combat a sense of hopelessness
  • holding beliefs that street drugs have positive effects on symptoms
  • assuming illegal drugs achieve the equivalent of prescription psychotropic medications


Cannabis describes any product derived from the following three plants: Cannabis sativa, Cannabis indica, and Cannabis ruderalis.

A 2020 review noted that cannabis use was associated with an earlier onset of schizophrenia, and frequent use could potentially double the chances of experiencing schizophrenia.

Cannabis products not containing psychoactive chemicals may hold more beneficial promise.

CBD (cannabidiol) is a compound found in the cannabis plant. A 2018 study found that CBD may be associated with therapeutic benefits when living with a psychotic disorder such as schizophrenia.

It’s crucial to note that CBD is different from THC (tetrahydrocannabinol), which is the active ingredient related to the hallucinogenic effects. In other words, THC is the ingredient that makes you “high.”


Unlike some substances, alcohol is readily available, making it an easy go-to for substance misuse.

It also may be considered socially acceptable. Many people go “out for a drink” to unwind from the day or catch up with friends.


A 2009 study on schizophrenia and substances noted high rates of nicotine misuse among people living with schizophrenia.

In this study, as many as 90% of people reported misusing nicotine.

The reason for this could be that the activation of the nicotinic acetylcholine receptor leads to a subjective soothing effect, temporarily calming or soothing symptoms.

There are several theories on why schizophrenia and substance misuse are often seen simultaneously.

These include:

  • genetics
  • neurobiology
  • self-medication

There appears to be a genetic overlap between schizophrenia and substance. For example, a 2021 study on alcohol use disorder co-occurring with schizophrenia found numerous shared genetic variants influencing both disorders.

Another overlap that might contribute to both conditions may be found in similar neurological pathways.

Research from 2016 suggests that the neurobiology that may predispose you to substance misuse may also be the same thing that increases the chances of experiencing schizophrenia.

Along with these evidence-based possibilities, experts in this study believe that the component of self-medication remains influential in why substance use and schizophrenia overlap.

Both substance use disorder and schizophrenia can be treated. As two separate conditions, they may require individual attention.

As one improves, symptoms of the other may diminish, as well.

Schizophrenia treatment traditionally involves medication to control symptoms in combination with psychotherapy approaches that can help you adapt to life with schizophrenia.

These may include individual therapy sessions, but they may also involve community-based programs to help you regain comfort in social circumstances such as work.

The goal of substance use disorder treatment is to stop drug use and remain drug-free, according to the National Institute on Drug Abuse.

The steps required to achieve these goals may vary depending on how intense your urge is to use a substance and how dependent your body has become.

Treatment for substance use disorder may mean spending time in an inpatient care facility to help eliminate the substance from your body and control symptoms of withdrawal.

It may also involve behavioral therapy, medication, and long-term management options to help prevent substance use in the future.

Psychotherapy approaches may focus on helping you learn new coping strategies when you feel like reaching for a substance.

With schizophrenia, this may mean adapting those new coping behaviors to moments when schizophrenia symptoms feel overwhelming.

Can drugs cause schizophrenia?

No. But drugs may increase the chances of experiencing symptoms if you already have underlying schizophrenia.

Does schizophrenia cause drug misuse?

Not directly. Living with schizophrenia may mean you have genetic or neurobiological traits that make you susceptible to both conditions.

Do drugs ever help schizophrenia?

Drugs are not a substitute for professional medical treatment and prescriptions. Some non-psychoactive substances such as CBD may hold therapeutic properties for schizophrenia.

Is self-medicating considered substance misuse?

Misuse does not have to be overuse. Substance misuse is any use of a substance beyond its recommended application or dose.

Schizophrenia is a mental health condition often linked to substance misuse.

Substance use won’t cause schizophrenia directly, but it can influence its expression if you are susceptible to the disorder.

Substance misuse is also common among people living with schizophrenia, possibly due to overlapping genetic and neurobiological factors, as well as the inclination to self-treat symptoms.

If you’re living with schizophrenia and are also experiencing substance use challenges, you can speak confidentially with a trained representative at any time by calling the SAMHSA National Helpline at 800-662-4357.

If you’re in need of urgent care for schizophrenia or substance use, call 911.