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Co-Occurring Disorders: Substance Use and Mental Health Disorders

When a person has both a mental health disorder (such as anxiety or depression) and a substance use disorder, it’s known as a comorbidity or co-occurring disorders.1, 2, 6 National surveys show that about half of people with a mental health disorder also have a co-occurring substance use disorder, and vice versa.2, 8

If you or a loved one are struggling with co-occurring disorders, you may already understand the challenges associated with both conditions. This article will help you better understand what co-occurring disorders are and how to find treatment that addresses both conditions, which may lead to more positive treatment outcomes.6, 11

What Are Co-Occurring Disorders?

A co-occurring disorder is when someone has at least one diagnosed mental health disorder and at least one diagnosed substance use disorder at the same time.2, 6 To be diagnosed with co-occurring disorders, a person needs to be evaluated and diagnosed with each disorder independently to ensure they aren’t experiencing effects and symptoms from just one disorder.6

Diagnosis can only be done by a healthcare professional and is based on the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5), which outlines diagnostic criteria for both substance use and mental health disorders.3

A substance use disorder (SUD) occurs when a person compulsively uses a substance despite negative consequences, including health issues, behavior changes, and an inability to fulfill important responsibilities to family, work, and their community.12

Mental health disorders affect mood, thinking, and a person’s behavior.12 Diagnosis occurs when a person over 18 has sustained mental, behavioral, and/or emotional impairment that interferes with their life.12 Common co-occurring mental health disorders include anxiety, depression, attention-deficit hyperactivity disorder (ADHD), PTSD, bipolar disorder, schizophrenia, and personality disorders.2, 6

How Common Are Co-Occurring Disorders?

According to the 2020 National Survey on Drug Use and Health, around 17 million (6.7%) adults aged 18 and older had both a SUD and a co-occurring mental illness.4 However, having both conditions simultaneously does not necessarily mean that one type of disorder is causing the other.2

Rather than a SUD causing a mental health disorder, or vice versa, there is a complex relationship between both disorders. The development, course, and treatment of one disorder can influence the development, course, and treatment of the other.6 Researchers have identified three major pathways to explain how co-occurring disorders occur:

  • Substance use disorders and many of the mental health conditions that co-occur share common risk factors. If you have a mental disorder, you are more likely to be predisposed to a substance use disorder and vice versa.5
  • Symptoms of mental illness can sometimes be relieved (or avoided) in the short term with drugs or alcohol. This is sometimes called “self-medicating,” however, alcohol and drugs are not considered medication, as they usually worsen health versus medications, which can support improved health.6
  • Substance use can contribute to changes in brain functioning and behavior that make someone more vulnerable to developing a mental health disorder.5

Symptoms of Co-occurring Disorders

It is important to understand that only a trained professional can diagnose someone with either a mental health disorder or any type of SUD. However, knowing the criteria for SUDs may be helpful in identifying the need to seek help for substance misuse.

The DSM-5 criteria for a SUD require that a person demonstrates at least 2 of the following symptoms within the last 12 months:3

  • A person will make unsuccessful attempts to cut back on using or to stop using a substance.
  • A person will use a substance in a risky and potentially dangerous situation, such as driving.
  • A person’s use of a substance results in increased interpersonal conflict with friends and family.
  • A person will neglect their responsibilities at home, work, or school to use a substance.
  • A person will give up their important hobbies and other leisure pursuits in favor of using substances.
  • A person will spend a lot of time and resources finding, using, and recovering from using a substance.
  • A person will use more of a substance than was originally intended.
  • A person will keep using a substance, despite knowing that the use of the substance makes a medical or emotional condition worsen.
  • A person will have strong cravings to use a substance.
  • A person will show signs of tolerance, which means they need more and more of a substance, or take it more frequently, to keep feeling its effects.
  • A person experiences withdrawal symptoms if they stop using or significantly reduce the amount of a substance.

A mental health disorder is a syndrome that indicates that a person has an issue with cognitive processes, regulation of emotion, or behaviors that then cause a person to have some type of dysfunction in their psychological, developmental, or biological processes.3 A mental disorder will usually cause a person to have some level of distress or inability to function in some aspect of their social, work, or other roles in their life.3

Types of Co-Occurring Disorders

Any mental health disorder can occur with a SUD, but the most commonly occurring disorders include:4, 6

Risk Factors for Co-Occurring Disorders

Risk factors are various biological, psychological, familial, or other social characteristics that, when present, may increase the likelihood of a person developing SUDs or mental health disorders.9 Many mental health disorders and SUDs have common risk factors, which include:10

  • Genetics and epigenetics. Around 40 to 60% of the development of a SUD may be related to genetics. Both SUDs and mental illness are heritable, which means a person is at increased risk should a parent or family member have one condition or co-occurring disorders. Epigenetics is an emerging area of research for co-occurring disorders; where researchers are trying to understand how a person’s environment interacts with their genetic vulnerability to put them at increased risk for developing co-occurring disorders.
  • Life experiences, such as childhood trauma, extraordinary stress, and drug use at an early age can lead to increased risk for SUDs and mental health disorders.
  • Affecting similar areas of the brain and acting on similar neurochemicals. Neurochemicals such as dopamine and GABA, as well as the parts of the brain involved in reward, decision-making, and emotions, play a role in both SUDs and mental health disorders.

Treatment for Co-Occurring Disorders

Treating both types of disorders concurrently in an integrated treatment approach is the standard of care for treating co-occurring substance use disorders and mental health disorders.11 In several studies, the integrated treatment approach consistently resulted in better outcomes than treating each disorder separately.13

Many of the approaches used in the treatment of co-occurring disorders involve some form of behavioral therapy or psychotherapy, along with strategies like education and employment skills to improve overall functioning and keep people motivated to stay in treatment.13 Behavioral therapies that address both types of disorders at the same time can include:13

  • Cognitive-behavioral therapy (CBT), which can help people identify and change negative thoughts and emotions, which lead to behaviors like substance use. CBT can be useful in restructuring negative thought patterns and reducing impulsivity, improving interpersonal functioning, and providing general support.
  • Dialectical behavioral therapy (DBT), an approach that can help curb drug use, suicidal thoughts and actions, and other types of self-harming behaviors.
  • Assertive community treatment (ACT), which involves community outreach and individualized approaches to treatment for people.
  • Contingency management (CM), an approach to treatment in which people are given vouchers or rewards for positive behaviors or outcomes that support their progress in recovery.

Find Co-Occurring Disorder Treatment Near Me

Finding integrated treatment for co-occurring substance use disorders and mental health disorders may be foundational to the rest of your recovery. Many people can benefit from a reputable treatment program that addresses both conditions at the same time and customizes care to address specific individual needs.11

American Addiction Centers (AAC) offers evidence-based treatment programs across the country that specialize in treating co-occurring conditions. If you or your loved one are struggling with co-occurring disorders, call our caring team at to learn about our facilities, how to pay with insurance, and what types of treatment may be right for you.

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