Co-Occurring Schizophrenia & Addiction

Addiction is a chronic mental health condition that often exists alongside other mental illnesses, including schizophrenia.

When two mental health conditions are present at the same time in the same individual, they are said to “co-occur,” which can make diagnosis and treatment more complex.

This article will take a closer look at the signs and risk factors associated with schizophrenia, its link to addiction, and how to get help if you or a loved one is battling a dual diagnosis, such as co-occurring schizophrenia and substance use disorder.

What Is Schizophrenia?

Schizophrenia is a psychotic disorder, which is a type of mental health condition that results in extreme loss of reality.

Most clinicians consider schizophrenia one of the most severe psychiatric diagnoses. Its origins date back to 1911 and psychiatrist Eugene Bleuler, who envisioned schizophrenia as the splitting of one’s thinking abilities from their personality.

Contrary to popular misconceptions, schizophrenia is not the same as multiple personality disorder, or dissociative identity disorder.

There is no single characteristic that defines schizophrenia. It is a heterogeneous disorder with a wide and diverse range of very serious symptoms.1

Signs & Symptoms of Schizophrenia

Image of a young woman sitting on a sofa with her knees pulled into her chest. The room is spinning around her.Recognizing the signs of schizophrenia as early as possible can help someone take the first steps toward recovery.

While symptoms will vary from person to person, schizophrenia is generally characterized by the following:1–3

Psychotic symptoms:

  • Delusions: Fixed beliefs held firmly by an individual, despite evidence that they are untrue, including delusions of persecution, grandiosity, or erotomania (the belief that someone is infatuated with them).
  • Hallucinations: These can occur in any sensory modality, but most often are auditory or visual (hearing or seeing things that are not really there).
  • Disorganized thoughts: Extremely illogical and unusual thought or speech patterns, such as frequently and abruptly switching topics or incoherence.
  • Disorganized motor actions: Extremely odd body movements, such as inappropriate smiling or laughing, or repeating certain motions over and over. This can also include catatonia, which is a state of immobility.

Negative symptoms:

  • Diminished emotional expression, which is an obvious lack of emotional engagement. 
  • Avolition, which presents as a decrease in self-initiated, motivated, personal activity.
  • Alogia, which is diminished speech output.
  • Anhedonia, the inability to experience pleasure.
  • Asociality, a significant decrease in engaging in social interactions.

Cognitive symptoms:

  • These include trouble with attention, focus, memory, and information processing.

How Is Schizophrenia Diagnosed?

Only a licensed physician can diagnose schizophrenia or any other mental disorder. Doctors typically utilize criteria outlined in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (5th ed.), or DSM-5, to reach a diagnosis.

This criteria specifies that:2

  • The individual must express 2 or more of the main symptoms (delusions, hallucinations, disorganized speech, disorganized behavior, or negative symptoms) during a 1-month period, and at least 1 of those symptoms must be either delusions, hallucinations, or disorganized speech.
  • The individual’s symptoms must result in significant dysfunction in their work, relationships, or self-care.
  • The individual must have displayed continuous signs of disturbance for at least 6 months.
  • The symptoms cannot be due to another mental health disorder or attributable to the effects of medications, drugs, or other medical conditions.

Doctors will also consider whether these symptoms are occurring for the first time and if they are acute and/or chronic.

Additionally, a number of neurological, medical, and other mental health conditions (e.g., bipolar disorder) may resemble schizophrenia, and only trained clinicians are qualified to make these distinctions and produce a formal diagnosis.

What Causes Schizophrenia?

The cause of schizophrenia is currently unknown. However, clinicians generally agree that a combination of neurological, biological, and environmental risk factors may result in various presentations of schizophrenia. These factors include:3

  • Brain structure and function.
  • Genetics.
  • Environmental components and life experiences (e.g., living in poverty or viral infections before birth).

Schizophrenia and Drug or Alcohol Addiction

Schizophrenia can often occur with drug or alcohol addiction. Research indicates more than half of people diagnosed with schizophrenia also develop a substance use disorder (SUD) in their lifetime.1

In 2020, an estimated 5.7 million people (or 2.2% of the U.S. population) suffered from co-occurring SUD and “severe mental illness” (a clinical term that includes schizophrenia).4

Among individuals with schizophrenia, the most commonly misused substances include:1

The combination of schizophrenia and substance misuse can worsen the course of both conditions and is associated with an increased risk of:1

  • Self-harm or suicide.
  • Shortened lifespan.
  • Violent behavior.
  • Homelessness.
  • Difficulty maintaining steady employment and relationships.

Does Schizophrenia Cause Addiction?

Man struggling with depression and addictionNo, schizophrenia does not “cause” addiction. However, people with schizophrenia have a higher likelihood of developing a substance use disorder.

Studies show that individuals with severe psychotic disorders, such as schizophrenia, are:1

  • 6 times as likely to engage in recreational drug use.*
  • 4 times as likely to engage in heavy alcohol use.*
  • 5 times as likely to engage in heavy cannabis use.*

*As compared to the general population

Does Substance Use Disorder Cause Schizophrenia?

No, just as schizophrenia doesn’t cause a substance use disorder, substance use disorders cannot “cause” schizophrenia. The link between both disorders is complicated, and researchers are still trying to better understand the ways they affect each other.1

However, addiction can worsen or exacerbate certain symptoms of schizophrenia.

In addition to the health risks mentioned above, persistent substance abuse alongside schizophrenia is also associated with poorer treatment outcomes. Certain substances can negatively interact with treatment medications, and some patients may not adhere to their doctors’ advice or stop use of treatment medications altogether.1

For these reasons, clinicians recognize the importance of early intervention and a professional, integrated approach when treating co-occurring schizophrenia and substance use disorder.

How to Treat Co-Occurring Schizophrenia and Substance Use Disorder

To treat co-occurring schizophrenia and substance use disorder, the standard of care is an integrated approach that combines treatment medications (e.g., antipsychotics) and behavioral psychotherapy.5

With a combined mental health and addiction treatment program, doctors, therapists, counselors, and case managers all work together to address both conditions at the same time and achieve the same goals.

At our inpatient addiction treatment facility near Dallas, we specialize in the treatment of co-occurring disorders. Our treatment plans are tailored to meet a patient’s individual needs and provide a combination of evidence-based therapies for addiction treatment.

To learn more about our quality programs, luxe rehab facility amenities, and how to help a loved one get into rehab, call us at . Our admissions navigators are available anytime to answer your questions and explain the admissions process.

Our staff can also review the various ways to pay for rehab and how to use insurance to pay for rehab. Or you can find out whether we accept your health insurance plan and confirm your benefits by filling out this quick and secure .

It’s important to remember that addiction and schizophrenia are both treatable. If you or someone you love is battling this dual diagnosis, take the first step toward recovery today.


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