The Five Most Common Co-Occurring Disorders in Addiction

Image of a woman alone and depressed

You may have heard of co-occurring disorders, particularly if you or a loved one struggle with addiction or mental illness.

Mental health professionals use this term to describe a situation where an individual is simultaneously diagnosed with more than one mental health condition.

However, psychologists may describe co-occurring disorders in various ways, some of which can be confusing for those outside the clinical field.

In its simplest term, a co-occurring disorder is when an individual has a co-existing mental health condition and a substance use disorder at the same time – for example, major depression and alcohol addiction.

Although co-occurring disorders are commonly used to describe substance use disorder and mental illness, psychologists may also use the term to describe a combination of other conditions, such as when someone is diagnosed with an intellectual disability and mental health disorder.

This article will explore the most common co-occurring disorders in addiction, their symptoms, and the most effective treatment options.

Let’s begin.

Other terms used to describe co-occurring disorders

Healthcare professionals may use various other terms to describe co-occurring disorders, including the following:

  • Dual diagnosis
  • Dual disorders
  • Concurrent disorders
  • Co-occurring mental health issues and substance abuse

The five most common co-occurring disorders in addiction

Although various mental health conditions may co-exist with substance use disorder, researchers have identified several that are more likely to co-occur with substance addiction.

These conditions include the following:

Let’s examine each of these conditions in detail.


Anxiety disorder up close

Anyone who’s ever experienced severe anxiety will tell you it’s not a pleasant condition.

A person with anxiety disorder can oscillate from being reasonably calm to experiencing heart-thumping, stomach-churning, sickening anxiety within seconds or minutes.

Anxiety disorders are one of the most prevalent mental health conditions, with studies showing that an estimated 31.1 percent of U.S. adults will experience an anxiety disorder at some stage.

Various situations can trigger crippling anxiety in an individual, such as a social event where a person may drink to alleviate stress or engage in drug use to manage anxious thoughts and feelings.

It’s common for anxiety sufferers to use substances as a coping mechanism.

These vulnerabilities can make anxiety sufferers more susceptible to developing a substance use disorder. Unfortunately, such outcomes worsen an individual’s anxiety if left untreated.


Emotions such as hopelessness and despair are just some of the symptoms associated with depression.

Depression is a mood disorder that causes chronic feelings of loss and sadness.

The persistent bleakness associated with depression can cause individuals to use various coping strategies to manage their symptoms, including substance abuse and behavioural addictions such as gaming, sex, or food addictions.

These distractions only worsen depression in the long term, and people often end up requiring some form of rehabilitation to help them recover.

Bipolar disorder

A man with bipolar disorder at the mirror. Bipolar affective disorder

Bipolar disorder is a severe mental health condition featuring profound mood swings, ranging from extreme highs (mania) to extreme lows (depression). 

People may experience various symptoms of bipolar, including:

  • Severe irritability, bouts of anger, and aggression
  • Intense excitement, happiness, and enthusiasm
  • A lack of judgement and poor decision making
  • Difficulty concentrating and remembering things
  • Feelings of guilt and despair
  • Agitation and restlessness
  • Hallucinations and disturbed or illogical thinking
  • Suicidal thoughts

Like most mental health disorders, people with bipolar disorder often use substances such as drugs or alcohol to cope with their unpleasant symptoms. 

Fortunately, bipolar is a treatable condition, provided you seek proper help and support from a licensed mental health professional.

Post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is a mental health disorder brought on by a traumatic event or sequence of traumatic events.

PTSD includes various unpleasant symptoms that can impair a person’s daily functioning; some of these symptoms include:

  • Avoidance – you may avoid people, places, objects, or situations that trigger traumatic memories or remind you of the trauma.
  • Reliving – you may experience flashbacks related to the traumatic event – symptoms may include nightmares, hallucinations, and reliving the event in your mind. 
  • Intrusive thoughts that induce negative feelings such as guilt, anger, or fear.
  • Hyperarousal – you may feel jumpy, alert, or on edge much of the time. In addition, you may have trouble sleeping and experience uncontrollable bursts of anger that occur seemingly out of nowhere.

Unsurprisingly, PTSD is one of the leading causes of substance use disorder.

The literature shows that up to 27.9 percent of female PTSD sufferers experience alcohol-related issues at some stage; however, up to twice as many males with PTSD report the same problems (51.9 percent).

Borderline personality disorder (BPD)

The research literature highlights the prevalence rates of substance abuse among those with borderline personality disorder (BPD).

Individuals with BPD are more likely to struggle with substance abuse, particularly polydrug use, which involves taking multiple drugs simultaneously to enhance desired effects.

Accurate diagnosis and treatment of concurrent disorders is essential for long-term recovery and requires significant expertise and a multidisciplinary approach.

Which condition comes first?

Co-occurring disorders have sparked much debate over the years – with researchers and mental health professionals debating which of these conditions presents first.

Much like the chicken and the egg debate, experts have long pondered on whether mental illness comes before addiction or the other way around. For instance, can we say that depression causes substance abuse, or does substance abuse cause depression?

These are not simple questions to answer as addiction is a multifaceted, complex condition; however, in our experience, mental illness comes first for many people, but addiction makes things much worse.

Addiction exacerbates mental illness

Signs a loved one is addicted - Centres for Health and Healing

Addiction can exacerbate existing psychological conditions – for instance, studies show that many people experience mental health symptoms after taking narcotics.

For example, those who abuse marijuana are vulnerable to developing specific mental health conditions or triggering underlying issues. 

Research shows that those who depend on marijuana are likely to have additional psychological complications, including:

  • Anxiety problems
  • Mood changes
  • Severe irritation
  • Manic depression

Treatment options for co-occurring disorders

As complex as co-occurring disorders can be to manage, various treatment options are available that treat a person’s addiction while also addressing any underlying mental health problems they may be experiencing.

Holistic treatment programs that address addiction and mental health issues together are highly recommended for client groups wanting to overcome the following conditions:

  • Substance use disorder
  • Behavioural addiction
  • Anxiety
  • Depression
  • Personality disorders

Individualised treatment programs – the most effective way to treat co-occurring disorders

Individualised treatment programs provide a bespoke, personalised approach to addiction and mental health treatment.

These programs are the most effective since they address all the parts that need to be unpacked and worked through to give you the best chance at long-term recovery.

Treating co-occurring disorders with dual diagnosis treatment

Adult man wants to know how to gain life balance

Since a co-occurring disorder is defined by the dual diagnosis of a substance use disorder and mental health disorder in the same person, dual diagnosis treatment is the most effective approach to recovery since it addresses and treats both conditions simultaneously.

Dual diagnosis treatment aims to provide an integrated approach to addiction and mental health issues; this primarily involves several critical components:

  • To help individuals become abstinent from substance use.
  • To help individuals manage their mental health problems.
  • To encourage and provide continuous support so that people can reach the highest level of independence possible after treatment.

How common are addiction and mental health disorders in Canada?

Studies by the Centre for Addiction and Mental Health (CAMH) examined the prevalence rates of substance use disorders and mental illness in Canada.

Here’s what they found:

  • Approximately 1 in 5 Canadian citizens struggle with mental illness each year.
  • Men are more likely to develop a substance use disorder than women; however, women are more likely to have increased rates of anxiety and mood disorders.
  • Around 39 percent of Ontario high-school children experience symptoms of depression and anxiety, with 17 percent experiencing severe psychological distress.
  • Substance use disorder and mental illness are the leading cause of disability among Canadians.

Young people are particularly impacted by mental illness and substance abuse in Canada. Additionally, the most affected individuals with these conditions are aged 15-24. 

Early treatment for co-occurring disorders is essential to avoid the long-term health risks associated with chronic substance abuse. 

A whole-person approach to addiction and mental health treatment at Centres for Health and Healing


At Centres for Health and Healing, we provide a personalised, holistic approach to treating addiction and mental health issues. This approach helps people overcome their addictions, allowing them to identify any potential triggers for substance use and gain deeper insight into why they might have used drugs or alcohol to cope in the first place.

Our integrated treatment program for dual diagnosis helps clients achieve lasting sobriety and wellness; among many things, this is achieved by addressing their individual needs, treatment goals, and preferences.

We provide various treatments and therapies to help you to stay on track with your recovery, which include the following:

Centres for Health and Healing include the above treatments as part of an individualised treatment program, helping you achieve your treatment goals and avoid relapse.

If you or a loved one require help and support for drug or alcohol addiction and/or a co-existing mental health condition, our specialist team can help. 

Contact our recovery centre in Ontario for further information and support.

Now is the time to begin your journey to health and wellness and, ultimately, to enjoy a life free from substances.

What our clients say about us

We understand how challenging it can be to seek professional help for an addiction or mental health concern. However, once you begin experiencing the benefits of treatment, you will start to feel much better about your decision.

If it helps, our past clients have some fantastic things to say about our treatment approach and how we have helped them achieve sobriety and mental wellness.

Our testimonials page features heartfelt stories from some of our past clients. So if you are anticipating treatment for an addiction or mental health issue, our client testimonials might help you with your decision-making:

Helpful sources

  1. Mental Illness and Addiction: Facts and Statistics – CAMH
  2. Co-Occurring Disorders: The Most Popular,, February 12, 2023
  3. Why Mental Health Disorders Co-Exist With Substance Use, Centres for Health and Healing, Lisa Davies, Program Director, January 24, 2023
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