What is Dual Diagnosis?

What is Dual Diagnosis?

When a substance use disorder and a mental illness occur together, it’s known as a dual diagnosis, or co-occurring disorders. Dual diagnosis has a high prevalence, affecting nearly eight million American adults every year, according to the National Alliance on Mental Illness. 1

Let’s look at the relationship between mental illness and addiction, including why it’s so common and what research says is the best way to treat dual diagnosis.

Mental Illness and Substance Use Disorders

Mental Illness

Mental illness is a physical health condition affecting the brain. It leads to changes in thought, behavior, and/or emotion. Mental illnesses like anxiety, depression, eating disorders, ADHD and bipolar reduce feelings of wellbeing and health, and they may cause troubles with relationships and in other areas of life.

Good mental health is the foundation of healthy relationships and emotional and physical wellbeing. The American Psychiatric Association estimates that nearly 20 percent of American adults have a mental illness, including 40 million who suffer from anxiety and 15 million who live with depression during any given year.

Mental illness is a treatable condition, and research is continually finding new and better ways to prevent and treat mental health problems. Successful treatment typically involves both medication and therapy.

Substance Use Disorders

Substance abuse, addiction and dependence were once diagnosed as separate disorders, but the most recent edition of the Diagnostic and Statistical Manual, which guides all mental health diagnoses, combined these and now diagnose them as a substance use disorder, which is deemed mild, moderate, or severe, depending on how many of the criteria are met.

Substance abuse is the act of using drugs or alcohol in a way that causes relationship, legal, financial or health problems. Substance abuse is a major risk factor for developing addiction and dependence.

Addiction results in compulsive substance abuse in spite of the problems it causes. People with an addiction generally find that they can’t quit even though they want to or have tried to. Addiction is caused by changes in the brain’s chemical functions and physical structures that lead to severe cravings and changes in patterns of thinking and behaving.

Medical detox ends the dependence on drugs or alcohol but doesn’t address addiction, which is a goal of psychotherapies like cognitive behavioral therapy or dialectical behavioral therapy.

Why Dual Diagnosis is Common

The National Alliance on Mental Illness points out that half of people with a severe mental illness, such as schizophrenia or bipolar disorder, and around a third of those who have any type of mental illness, including depression or anxiety, also suffer from a substance use disorder. The National Institute on Drug Abuse cites three reasons why dual diagnosis is so prevalent:

  • Drug abuse may cause a mental illness to develop, and it almost always worsens a current mental condition
  • People who have any type of mental illness may self-medicate uncomfortable symptoms with alcohol or drugs, increasing the risk of addiction and dependence
  • Mental illnesses and substance use disorders have overlapping risk factors, leaving some at a high risk for developing both

Risk Factors

Three important risk factors can increase the chances of dual diagnosis:

A number genes are associated with both mental illness and substance abuse. Some directly increase the risk, such as how substances act on the brain and are metabolized by the body. Others impact the risk indirectly, such as a low tolerance for stress or a predisposition to engage in risky behaviors, including substance abuse.

Addiction and dependence occur as the result of changes in the regions of the brain associated with memory, learning, and reward, which largely involve the dopamine system. Dopamine, a key neurotransmitter in the reward circuit, plays an important role in mental illness.

A person’s environment has a major impact on the development of both mental illness and addiction. For example, a dysfunctional family system can lead to anxiety and depression, and it can also contribute to drug or alcohol abuse as a way to escape or cope with the problems at home.

Common Dual-Diagnosis

The following mental illnesses occur with substance use disorders more often than others.

Characterized by feelings of impending doom and restlessness, anxiety disorders include social anxiety disorder and panic disorder. People with anxiety often use alcohol or drugs as self-medication to reduce symptoms.

Depressive disorders like bipolar disorder and major depression are linked to a greater risk for alcohol or drug abuse, which eventually makes the depression worse.

More commonly known as OCD, this disorder causes repetitive behaviors and cyclic thoughts that are difficult to stop. People with OCD may engage in substance abuse as a way to curb repetitive actions or quiet intrusive thoughts.

Known as PTSD, this disorder results from traumas like being the victim of or witness to violence or death, being involved in an accident or natural disaster, or suffering sexual or physical abuse. One study found that 40 percent of clients entering residential rehab have PTSD.2 Additionally, more than half of all veterans who saw combat and have PTSD will develop alcoholism later on.

People with eating disorders like anorexia, bulimia, or binge eating disorder often use drugs or alcohol to curb their appetite or cope with feelings of inadequacy or low self-esteem. An article published in the journal Social Work reveals that about 50 percent of people with an eating disorder engage in substance abuse. 3 By contrast, less than ten percent of the general population abuses alcohol or drugs.

Integrated Treatment is Essential

Because of the high occurrence of dual diagnosis, mental health clinics and addiction rehab settings use an integrated screening protocol to help find multiple diagnoses. The simple screening involves a range of questions that help care providers decide whether you need a more comprehensive evaluation.

The first stop in dual diagnosis treatment is medical detox, which ends the physical dependence on drugs or alcohol so that brain function can normalize and treatment can begin.

Dual diagnosis rehab requires an integrated protocol that treats both the mental illness and the substance use disorder in tandem, each with the other in mind. Treating just the substance use disorder or just the mental illness will have little effect on the other co-occurring disorder.

According to the Substance Abuse and Mental Health Services Administration, there is no single pathway to recovery.4 A holistic approach to treatment offers the best chances of long-term sobriety. A holistic approach involves a range of traditional and complementary treatment therapies that address a wide range of physical, mental and spiritual issues to promote whole-self healing.

Traditional therapies include cognitive-behavioral therapy, trauma-based therapies, family therapy and pharmacotherapy, which is the use of medications to reduce symptoms of mental illness or ease the cravings associated with addiction.

Complementary therapies include art therapy, mindfulness meditation and restorative yoga. These types of experiential therapies help clients express difficult emotions and synthesize troubling experiences. They improve engagement in treatment and help with spiritual healing.

Through a variety of therapies, individuals in treatment:

  • Identify and change problematic patterns of thinking and behaving
  • Develop coping skills for handling cravings, stress, symptoms of the mental illness and other relapse triggers
  • Address the issues that contribute to the mental illness and the addiction, which commonly include chronic stress, trauma and family dysfunction
  • Find purpose and meaning in a sober life
  • Learn to enjoy life and relax without needing alcohol or drugs
  • Repair damaged relationships and work through family issues
  • Repair damage to other areas of life, including addressing legal, financial, health or relationship problems
  • Learn essential life skills that promote independence and support recovery for the long-term

The more engaged you are with your treatment program, the better the outcomes of treatment. Additionally, staying in treatment for an appropriate period of time dramatically increases your chances of successful recovery for the long-term. The National Institute on Drug Abuse stresses that treatment should last at least 90 days for optimal effectiveness.5

Dual Diagnosis Treatment Works

Dual diagnosis treatment works for most people who fully participate in their program and stay in treatment for an appropriate amount of time. Treatment helps develop the skills and strategies to cope with symptoms of mental illness and cravings caused by the addiction. It gives the tools needed to rebuild a life and improve a sense of wellbeing, and it opens the door to true happiness down the road.


  1. https://www.nami.org/Learn-More/Mental-Health-Conditions/Related-Conditions/Dual-Diagnosis
  2. http://pubs.niaaa.nih.gov/publications/arh23-4/256-262.pdf
  3. http://www.socialworktoday.com/archive/070708p30.shtml
  4. https://www.samhsa.gov/find-help/recovery
  5. https://www.drugabuse.gov/publications/principles-drug-addiction-treatment-research-based-guide-third-edition/frequently-asked-questions/how-long-does-drug-addiction-treatment