Substance Abuse and Co-occurring Disorders Explained

woman sadly looking at glass alcohol

Mental health professionals use various terms to describe two mental health conditions in the same person; for instance, an individual might be diagnosed with an alcohol use disorder and depression.

These terms include concurrent, coexisting, dual-diagnosis, or co-occurring disorders.

What is meant by “co-occurring disorders”?

A co-occurring disorder describes the condition in which a person simultaneously has a coexisting mental health condition and a substance use disorder.

However, co-occurring disorders can also be applied to other combinations of conditions, such as anxiety disorder and an intellectual disability.

Mental health disorders and substance use disorders are prevalent conditions, and when they coexist, they can significantly increase the severity of a person’s symptoms.

Living with a co-occurring disorder

Substance use disorders and mental health conditions can be experienced in isolation, meaning that a person has only one disorder. Still, when these conditions coincide in the same individual, the symptoms are usually more severe and complex to treat.


The term “dual” describes something that consists of two parts, aspects, or elements; in other words, dual is a synonym for “double.”

In the case of co-occurring disorders, a person has two conditions, for example, a personality disorder and opioid use disorder.

Co-occurring disorders are defined by the dual diagnosis of a substance use disorder and mental health condition in the same individual.

A mental health professional may diagnose one condition first and then the other later on or at the same time. This is dependent on how an individual presents clinically and various other factors.

What mental health conditions co-occur with substance addiction?

Anxiety disorder up close

Some of the common mental health disorders that co-occur with substance addiction include:

  • Anxiety disorders
  • Bipolar disorder
  • Attention deficit disorder
  • Depression
  • Personality disorders such as borderline personality disorder or antisocial personality disorder
  • Schizophrenia

Why co-occurring disorders can be tricky to diagnose

Studies show that co-occurring disorders can be complex to diagnose since many other mental health disorder symptoms and those in substance detox can often overlap.

Some addiction specialists believe that the best approach to treatment is for patients to undergo detox from a substance before a therapist attempts to make a diagnosis of another mental health condition.


Some of the risk factors associated with substance use disorder include:

  • Adverse childhood experiences.
  • A history of trauma.
  • Post-traumatic stress disorder 

Those with substance abuse issues often have a history of trauma, such as ongoing physical, mental, or sexual abuse in childhood.

Other traumatic experiences that may lead to addiction involve domestic violence, being a prisoner of war, or the death of a loved one.

The researchers found a profound link between childhood traumatic experiences and addictive behaviours in adulthood.

Moreover, the research literature states that addiction and trauma are strongly connected. 

Trauma and addiction statistics

A study by the National Alliance on Mental illness (NAMI) revealed that an estimated 17 million US citizens simultaneously had a substance use disorder and mental health condition.

Another study showed that children who experienced trauma were five times more likely to suffer from alcoholism.

Psychological trauma can create various mental health problems, including post-traumatic stress disorder (PTSD) and depression.

These conditions often lead people to self-medicate through drug misuse or excessive drinking to cope with their complicated past.

Co-occurring disorder symptoms

Characteristics of adult children of alcoholics - Centres for Health and Healing

Symptoms of a co-occurring disorder can vary between people. However, symptoms typically involve:

  • Sudden changes in behaviour
  • Isolating yourself from family and friends
  • Engaging in dangerous or risky-behaviours
  • Having no control over substance use
  • Using substances in unsafe environments or conditions
  • Developing a high tolerance to a substance and needing more of it to get high or feel normal
  • Withdrawal symptoms when not taking a substance
  • Neglecting your health and personal hygiene
  • Lying to your family and friends about your whereabouts 
  • Needing substances to feel like your usual self

Co-occurring disorders explained

Various concurrent disorders can co-occur with substance addiction, and you may wonder whether you have a mental health condition such as depression or a personality disorder (as well as a substance addiction).

If you think you have any of the following symptoms, you must speak to your doctor or mental health professional for advice and treatment.

Anxiety disorders 

Anxiety disorders are a group of mental health conditions that include social anxiety disorder, post-traumatic stress disorder, obsessive-compulsive disorder, and generalised anxiety disorder.

The research literature shows substance use and anxiety disorders are the most prevalent and most commonly diagnosed concurrent disorders.

Concurrent disorders can make a person’s symptoms more severe than if they only had one condition – when anxiety disorders and substance addiction co-occur, symptoms can be more persistent and severe than if the person only had a single condition.

Unfortunately, due to the severe symptoms of an anxiety disorder, a person will often self-medicate to feel better in the hopes that this will alleviate matters. However, this can often lead to addiction or a substance use disorder.

Personality disorders 

Personality disorders involve a long-term pattern of unhealthy and inflexible thoughts and behaviours; they are a group of mental illnesses that affect a person’s relationships and daily life.

Some personality disorders include narcissistic personality disorder, borderline personality disorder, and antisocial personality disorder (the latter two conditions are the most common).

Studies show that personality disorders are more likely to co-occur with drug abuse than any other substance (such as alcohol use disorder).


Depression treatment at CFHH

Depression frequently co-occurs with substance abuse. 

Addiction specialists explain that the relationship between depression and substance use disorder is bi-directional – meaning that people suffering from depression are more likely to abuse substances, and those who abuse substances are likely to be depressed.

Many might not be surprised to learn that those who suffer from depression use substances such as drugs or alcohol to feel better or elevate their mood – the goal is to escape unpleasant feelings such as shame, guilt, or sadness.

However, saturating these emotions with alcohol, a depressant, can worsen a person’s depressive symptoms, affecting their concentration, decision-making, and overall response to things.

Addiction specialists say that treating co-occurring depression and drug use can be complex since some drug abuse symptoms mimic depression. Therefore it can be challenging to diagnose depression when an individual is actively using drugs.

Mood disorders

The research literature states that substance use disorders commonly coexist with bipolar disorder and major depressive disorder.

Statistics show that around 20-70 percent of those with bipolar disorder also have substance use disorder (Substance Abuse and Depression, Psycom, Kathleen Smith, Ph.D., LPC, September 14, 2022).

Additionally, around 10-30 percent of those with the major depressive disorder will also have co-occurring substance addiction (Substance Abuse and Depression, Psycom, Kathleen Smith, Ph.D., LPC, September 14, 2022).

Risk factors for concurrent disorders

Various risk factors may put a person at higher risk of developing a co-occurring disorder.

However, studies show that common risk factors for developing a co-occurring disorder include:

  • A family history of mental illness
  • A history of adverse childhood experiences or other trauma
  • Genetics
  • Environmental influences
  • Specific personality characteristics, such as how you respond to stress 

Finding treatment

Young woman talking with psychotherapist

Treatment for a co-occurring disorder may vary; however, treating both conditions is crucial.

Many rehabilitation centres offer dual-diagnosis treatment, which helps patients control their substance use disorder while also being treated for an existing mental health condition.

Dual-diagnosis provides patients with an integrated treatment approach that addresses (and treats) an individual’s substance use disorder while engaging in therapy for a mental health condition such as depression or a personality disorder.

It is common practice for a person to undergo substance detox before any other treatment medication is added to their program. This approach prevents any potential side effects of combining substances and mental health medication.

Studies on the benefits of dual-diagnosis treatment suggest that patients experience better outcomes when treated simultaneously for a co-occurring disorder instead of treating the conditions separately.

Contacting Centres for Health and Healing 

If you think you have symptoms of a co-occurring disorder, you must speak to a mental health professional who can help.

We treat various mental health disorders and addictions, including concurrent disorders, at Centres for Health and Healing.

Our staff are compassionate, understanding and trauma-informed to help you get the most out of your treatment – we have a range of treatment options depending on your history, symptoms, and condition(s).

Speak to a friendly team member today.

Additional resources

  1. Substance Abuse and Depression, Psycom, Kathleen Smith, Ph.D., LPC, September 14, 2022
  2. Co-Occurring Disorders, Psychology Today
Lisa Davies - Program Director of Vaughan Recovery and Kirby Estate

About Lisa Davies

Lisa is the Program Director at Centres for Health and Healing. She lived for most of her life in the Durham region, before moving to Peel five years ago.

Lisa is a Master Hypnotist and is certified in Hypnotherapy (2008), Self-Hypnosis and in 5-phase Advanced Therapeutic Healing. As a Member of National Guild of Hypnotists, she is also specialized in hypnosis training in pediatrics, pain management, neuro-linguistic and stage programming.

Read more

Call now
Ready to get help?
Call for treatment options
Need financing?
Payment plans available