What are concurrent disorders?
Mental illnesses are conditions in which people’s thinking, mood and behaviours may negatively affect their day-to-day functioning. Mental illnesses can affect people of any age, but they often appear in teenage years or early adulthood.
There are several types of mental illnesses. Mental health problems can include depression, anxiety, schizophrenia and many other disorders, as well as addictions (Public Health Agency of Canada, 2015a). They can range from single, short-lived episodes to chronic disorders (Public Health Agency of Canada, 2015b).
Addiction occurs along a continuum from mild to moderate to severe. In the extreme, it can be characterized by the four Cs: craving, loss of control of the amount or frequency of use, compulsion to use and use despite negative consequences.
A person with a mental health problem has a higher risk of having an addiction problem, just as a person with an addiction problem has an increased chance of having a mental health problem. When someone is diagnosed with both mental health and addiction dis-orders, they are said to have concurrent disorders.
Concurrent disorders can include combinations such as:
- an anxiety disorder and problematic alcohol use
- schizophrenia and cannabis use disorder
- borderline personality disorder and substance use disorder
- depression and addiction to sleeping pills.
Many other combinations are possible, because there are many types of mental health and addictive disorders. It should also be noted that people with concurrent disorders may have more than one addictive disorder and more than one mental health disorder. It is therefore important to view concurrent disorders as involving multiple factors rather than just two disorders, and that these factors are often intertwined.
How common are concurrent disorders?
A 2020 national survey on concurrent disorders among adults aged 18 or older in the United States found that in the past year:
- 14.2 per cent (or 35.9 million people) had mental illness only
- 8.3 per cent (or 20.9 million people) had a substance use disorder only
- 6.7 per cent (or 17.0 million people) had both mental illness and a substance use disorder (SAMHSA, 2021).
People with substance use disorders are more likely to also have mental health problems than those without substance use disorders (Chan et al., 2008; Harris & Edlund, 2005). About three quarters of people with addictive disorders have pre-existing mental health issues (Rush et al., 2010). The risk of having concurrent disorders increases with the number of substances used (Cooper & Calderwood, 2004).
In 2012, an estimated 6.1 per cent of the Canadian household population aged 15 to 64 had a mood/anxiety disorder in the previous year and 3.8 per cent had a substance use disorder.
An additional 1.2 per cent experienced concurrent mood/anxiety and substance use disorders (Khan, 2017).
Understanding concurrent disorders
Concurrent disorders is a term for any combination of mental health and substance use problems. There is no symptom or group of symptoms that is common to all combinations.
The combinations of concurrent disorders can be divided into eight main groups:
- Substance use and psychotic disorders: conditions that affect the mind, in which people have trouble distinguishing between what is real and what is not (e.g., schizophrenia).
- Substance use and impulsivity: problems of anger and aggression, including risk of harm to self or others
- Substance use and mood disorders: conditions involving depression and affective instability (i.e., rapid and intense mood swings) (e.g., bipolar disorder)
- Substance use and anxiety disorders: features of excessive fear and anxiety and related behavioural disturbances
- Substance use and trauma- and stressor-related disorders: in which exposure to a traumatic or stressful event has caused a person to develop symptoms that bring about significant distress, behavioural disturbances and/or functional impairment
- Substance use and feeding and eating disorders: conditions involving an obsession with food, weight and/or appearance that negatively affect people’s health and daily living (e.g., anorexia nervosa, bulimia nervosa, binge-eating disorder)
- Substance use and personality disorders: conditions involving a lack of adaptability and limited coping responses that lead to negative consequences (e.g., borderline personality disorder).
- Substance use and other addictive behaviours: problematic use of substances and other addictive behaviours (e.g., problem gambling, technology use) that cause negative consequences in several areas of a person’s life.
How does each problem affect other co-occuring ones?
Some people with concurrent disorders have severe problems with both their mental health and their addictive behaviour. This makes it hard for them to function day-to-day. While other people may have milder co-occurring problems, the impact on their lives can still be quite negative.
Concurrent disorders may interact in several ways, such as:
- substance use and/or other addictive behaviours can make mental health problems worse
- substance use and other addictive behaviours can mimic or hide the symptoms of mental health problems
- sometimes people turn to substance use to “relieve” or escape the symptoms of mental health problems
- some substances can make mental health medications less effective
- using substances can make people forget to take their medica-tions, which can make the mental health problems come back (“relapse”) or worsen
- when a person relapses with one problem, it can trigger the symptoms of the other problem.
A person with concurrent disorders is at higher risk of experi-encing more serious medical, social and emotional problems than if they had only one condition. The interaction between the effects of substance use and mental health symptoms can prolong treatment and make it less effective.
What causes concurrent disorders?
When do concurrent disorders begin?
Mental health and substance use problems can begin at any time: from childhood to older age. When problems begin early and are severe, recovery may take longer and the person may need more support. On the other hand, if the problem is recognized and treated early, the person has a better chance of a quicker and fuller recovery.
People often ask, “Which came first: the mental health problem or the substance use problem?” This is a hard question to answer. Often it is more useful to think of them as problems that interact with each other.
What causes concurrent disorders?
There is no one cause of concurrent disorders. Each person’s situation is different and unique. Here are some reasons why a person might develop both a mental health and a substance use problem:
Common factor model
In this model, a common factor leads to both mental health and substance use problems. This factor may be biological or it may be an event, such as emotional or physical trauma.
Secondary addiction model
In this model, the mental health problem triggers the substance use problem. Some people who have a mental health problem may use substances to feel better. While substance use is risky in such cases, it can help people forget their problems or relieve symptoms, at least in the short term. People sometimes talk about using substances for “self-medication.”
For a person who is more vulnerable to mental health issues, even moderate amounts of substance use may create problems.
Secondary mental health model
In this model, the substance use problem triggers the mental health problem. Substance use can cause harmful changes in people’s lives and relationships. For example, substance use problems may cause a person to lose their job. Mental health problems may result from these indirect effects of substance use.
Some effects of substance use can mimic symptoms of a mental health problem, such as depression, anxiety, impulsivity or hal-lucinations. This is sometimes described as substance-induced mental health problems.
Bidirectional
In this model, each problem increases a person’s vulnerability to the other. For example, if someone with depression is also misusing alcohol, the alcohol use disorder may lead to job loss, worsening the depression, and the depression may lead to relationship problems, contributing to increased alcohol use.
It is important to mention that there are also social, physical and situational factors that can affect the experience of concurrent disorders and further complicate a person’s problems. Some factors include:
- chronic physical illness
- experience of trauma
- stigma
- social determinants of health
- acquired brain injury.
It can be helpful to think of causal factors in the following three ways:
- the factors that might predispose or make someone vulnerable to a problem
- the factors that trigger the first event
- the factors that cause a problem to continue.
Trauma
“Individual trauma results from an event, series of events or set of circumstances that is experienced by an individual as physically or emotionally harmful or life-threatening and that has lasting adverse effects on the individual’s functioning and mental, physical, social, emotional or spiritual well-being” (SAMHSA, 2014a).
The relationship between trauma and substance use is bidirect-ional: people who use substances are at risk of being exposed to traumatic events and, therefore, are more vulnerable to the effects of trauma. On the other side, traumatic experiences increase the risk of substance use. Similarly, mental illness increases one’s vulnerability to the effects of trauma, and trauma — such as adverse childhood experiences (ACE) — increases the risk of mental health problems (SAMHSA, 2014b).
Many people diagnosed with a mental health, substance use or other addictive disorder report exposure to trauma (Rosenberg, 2011; SAMHSA, 2014b). Additionally, people who use substances are often exposed to traumatic circumstances (e.g., compromised home setting, witnessing unintentional death by poisoned drug supply, experiencing non-fatal overdose, etc.) (SAMHSA, 2014b).
Stigma
Stigma occurs when people avoid or look down on a person or a group that has unusual or different traits compared to the rest of society. Stigma is a complex concept that involves attitudes, feelings and behaviour; it results from and gives rise to prejudice and discrimination.
When a negative label is placed on an individual or group, it can lead to bias, misperception, myths, stereotyping, prejudice and discrimination. Individuals who face this stigma often internalize the language and attitudes of other people. This may damage a person’s self-perception, decrease optimism and confidence and set up negative expectations.
Social determinants of health
The social determinants of health are nonmedical factors that can influence a person’s health and well-being, as well as affect their access to timely, appropriate and high-quality health care. The social determinants of health can also influence the way a person is treated while receiving care and the outcome of the care provided. Some examples of social determinants of health are:
- gender
- race
- age
- income
- education
- sexual orientation
- immigration or refugee status
- unemployment and job insecurity
- housing and food insecurity.
Acquired brain injury and concurrent disorders
Acquired brain injury (ABI) is damage to the brain:
- caused by a traumatic injury (e.g., car accident, fall, assault) or a medical problem/disease (e.g., brain not getting enough oxygen, a tumour, brain aneurysm, infection or stroke).
- that occurs after birth and is not related to a congenital disorder/ developmental disability (e.g., cerebral palsy) or processes that gradually damage the brain (e.g., Alzheimer’s disease, Parkinson’s disease).
Acquired brain injuries can occur in different areas of the brain. The relationship between ABIs and mental health and substance use disorders is bidirectional (i.e., each problem increases the person’s vulnerability to the other). For example, intoxication increases the risk of having a brain injury, and each fall or over-dose increases the likelihood of lingering cognitive impairment. A brain injury may cause or worsen mental health symptoms or increase one’s vulnerability to substance use disorders.
Whether a person has a mental health or substance use problem, or both, the cognitive and mental health consequences of a brain injury may make it more difficult to benefit from treatment. If you or someone you support has a history of brain injury and is seeking mental health or addiction treatment, you can increase the likelihood of a better outcome by ensuring that the health care team is informed about the person’s ABI history, so it can be taken into account during the care planning process (Selby et al., 2022).
How are concurrent disorders treated?
People with concurrent disorders are likely to receive treatment in one of the following settings:
- primary health care (e.g., family doctors)
- mental health agencies/clinics
- substance use agencies/clinics
- specialized concurrent disorders treatment programs.
The treatment setting often depends on how severe a person’s problems are and what local services are available.
Often, people who have concurrent disorders have to receive mental health treatment through one service and addiction treatment at another service. Sometimes the services are not connected at all and do not communicate with one another. This can make it very challenging for clients to navigate between the two and experience the full benefits of the available treatment. Communication and collaboration across programs serving the same person enhances care and supports recovery.
Although the overall treatment plan should consider both mental health and addiction problems, it is sometimes helpful to treat one problem first. For example, most people who have concurrent mood and alcohol disorders are likely to recover better if alcohol use is addressed first. As another example, a person who is being treated for concurrent disorders may have an episode in which the mental health problem gets worse. In this type of situation, treatment might focus on the mental health problem, rather than on the substance use.
Typically, however, people with concurrent disorders have the best success with integrated treatment, which is when both problems are addressed at the same time, in a coordinated way.
What is integrated treatment?
Integrated treatment is a way of making sure that care is co-ordinated and comprehensive, in ways that appear to be seamless to the client. Ideally, it ensures that the client receives help not only with their concurrent disorders, but also in other life areas. This helps to:
- maintain treatment success
- prevent relapses
- ensure the client’s basic life needs are being met
- ensure access to holistic care and psychosocial support.
Integrated treatment works best if the client has a stable, trusting, long-term relationship with one case coordinator, who is typically a health care professional, such as a nurse, social worker or thera-pist. Even though one person is responsible for overseeing the client’s treatment, the client may work with a team of profes-sionals, including psychiatrists, social workers, pharmacists, nurses and therapists.
Where do people get treatment?
People with concurrent disorders who are clinically stable and have social support can be treated in the community, such as through their family doctor or community clinic (e.g., addiction counselling services). People with severe problems may need specialized care for concurrent disorders.
Of note, it can be challenging to obtain access to concurrent disorders services without a doctor’s referral. If the person with concurrent disorders does not have a family doctor and requires a doctor’s referral to access services, they can consider attending a walk-in clinic or primary care team to request support for a referral. Community addiction services or case management services may also be able to help connect a client to a family doctor so that they can obtain a referral for more specialized concurrent disorder services/treatments.
Treatment goals
In the past, addiction and mental health treatment services have each treated problems differently. They have also had different ways of thinking about problems. Clients who received treatment from both systems may have been confused by the differences. For example, many addiction services have adopted harm reduction principles, which uses a range of strategies that include safer use,
managed use, abstinence and meeting people “where they’re at” in terms of their drug use. As a result, possible client goals may include using substances in safer ways, reducing the frequency and amount of substances or stopping use entirely (for more information on harm reduction, see page 47). Mental health programs that have not adopted harm reduction principles may require clients to completely stop using substances before they can get treatment, forcing an undesired goal of abstinence.
Fortunately, staff in many mental health and substance use pro-grams work closely together. As a result, in working towards their own goals, clients can:
- decide what a healthy future and recovery means for them
- find ways to live a healthy and meaningful life
- make gains in their recovery journey in line with their goals.
A client’s treatment plan should be customized, using the most appropriate approaches for each client’s particular needs and addressing both addictive behaviours and mental health problems.
Types of treatment
Treatment for concurrent disorders includes psychosocial treat-ments and medication. Clients may receive one or the other or both.
Psychosocial treatments
Psychosocial treatments include different types of psychotherapy and social and vocational training and aim to provide support, education and guidance to people with mental illness and their families (NAMI, 2024). Psychosocial treatments are an important part of treatment for concurrent disorders. They include:
- psychoeducation
- counselling and psychotherapy (individual and group therapy)
- family therapy
- case management/case coordination support and practical sup-port with housing, employment, finances, social support, etc.
- building healthy lifestyles and engaging in leisure and other meaningful activities
- peer support and mutual aid.
Psychoeducation
Psychoeducation is helping people learn about mental health and substance use issues. People who know about their problems are more able to make informed choices.
While all people should receive psychoeducation when they begin treatment for concurrent disorders, as they move through recovery they may benefit even more from psychoeducation. For people who have milder problems, psychoeducation alone may be the only treatment they need.
Psychoeducation sessions include discussions about:
- what causes addictive behaviours and mental health problems
- how the problems might be treated
- how to self-manage the problems (if possible)
- how to prevent or reduce the chance of future episodes
- how to enhance hope, build support and learn the skills that lead to recovery.
Psychotherapy
Psychotherapy is sometimes called “talk therapy.” It helps people manage their problems by looking at how they think, act, feel and interact with others.
There are many different types of psychotherapy. Some types are better for certain problems. Psychotherapy can be either short-term or long-term and can be offered in-person or virtually.
Short-term therapy has a specific focus and structure. The therapist is active and directs the process. This type of treatment is usually no longer than 10 to 20 sessions.
In long-term therapy, the therapist is generally less active, and the process is less structured. The treatment usually lasts at least one year. The aim is to help the client work through deep issues.
Successful therapy depends on a supportive, comfortable relation-ship with a trusted therapist. The therapist can be a doctor, social worker, occupational therapist, psychotherapist, nurse or psychologist.
Therapists are trained in different types of psychotherapy. They may work in hospitals, clinics or private practice.
Cognitive-behavioural therapy
Cognitive-behavioural therapy (CBT) is a type of short-term psychotherapy. CBT works well for a broad range of concurrent disorders. CBT is a brief, problem-focused approach to treatment based on the cognitive (i.e., the way we think) and behavioural (i.e., the way we act) aspects of mental health disorders. Since the way a person thinks can affect how they feel and behave, the aim of CBT is to help a person develop healthier ways of thinking, which can then
lead to a change in their feelings and behaviours. Some deeply held thoughts have a strong influence on our mood and behaviour. For instance, if we are depressed and drinking too much and think no treatment will help, then we might not seek treatment. CBT helps people identify and shift such thoughts and learn new strategies to cope better in everyday life.
Dialectical behavioural therapy
Dialectical behavioural therapy (DBT) is a type of cognitive-behavioural therapy. It is used to treat a range of behaviour challenges. DBT draws on Western cognitive-behaviour tech-niques and Eastern mindfulness philosophies. It teaches clients how to:
become more aware of their thoughts and actions
- tolerate distress
- manage their emotions
- improve their relationships with other people.
Insight-oriented or psychodynamic psychotherapies
Insight-oriented or psychodynamic psychotherapy tends to be longer term and less structured. These therapies reduce distress by helping people understand what makes them act the way they do.
Interpersonal therapy
Interpersonal therapy helps clients get better at communicating and interacting with others. This therapy helps people:
- look at how they interact with others
- identify issues and problems in relationships
- explore ways to make changes.
Interpersonal group therapy focuses on the interactions among group members.
Group therapy
Group therapy can help people who have concurrent disorders. Group therapy includes treatments such as:
- cognitive-behavioural therapy
- dialectical behavioural therapy
- interpersonal therapy
- psychoeducation and recovery-focused programming.
A group setting can be a safe space to discuss issues such as family relationships, medication side-effects and relapses.
Family therapy and family support groups
Active social support is a key ingredient in successful ongoing recovery. Family members can support the person with concurrent disorders by learning about substance use and mental health problems and participating in support groups. Family members may also engage in therapy themselves. In family therapy, thera-pists usually work with one family at a time and can help:
- teach families about concurrent disorders
- offer advice and support to family members.
Sometimes family therapy is offered in a group setting with other families in similar situations. Group members can share feelings and experiences with other families who can understand and support them.
It can be challenging to make recovery gains when there is a lack of social and family support. In these situations, it is encouraged that individuals work toward building their support networks by getting involved in community programs, building trusting relationships and trying out strategies that help to broaden and deepen connections.
Peer support groups
Peer support groups can be an important part of treatment. A peer support group is a group of people who all have concurrent disorders and who can share their struggles in a safe, supportive environment. Group members accept and understand one another and may develop trusted relationships and healthy bonds. People who have recently been diagnosed with concurrent disorders can benefit from the experiences of others.
There are peer support groups for clients and for families. Some examples of peer support groups include Double Recovery Groups, SMART Recovery Meetings and 12 Step Groups.
Special treatment situations
During recovery, people may benefit from specific interventions, such as:
- withdrawal management
- crisis management
- hospitalization.
Withdrawal management
Sometimes, people need help with withdrawal from substance use. Withdrawal management helps individuals manage symptoms that occur when they stop using a substance. This term is also known as detoxification or detox. Withdrawal management is sometimes required prior to substance use treatment and may occur with or without the use of medications, which help alleviate symptoms.
Withdrawal management can vary in intensity and can occur in several different settings, such as:
- primary care provider’s office: prescribers may provide medications that can be taken at home
- substance use–specific ambulatory/outpatient services: these programs may have specialty staff that can provide support similar to primary care providers. Some places may offer extended onsite monitoring for several hours each day
- emergency departments (ED) and inpatient units: these units provide short-term withdrawal management with medications
- non-medical/community withdrawal management services: this is a facility where the person receives more intensive care and 24-hour supervision, usually staffed by non-medical trained staff. Medication may be used in these facilities
- medical withdrawal management services: this may be needed if a client has severe withdrawal symptoms, such as seizures or hallucinations. These services are staffed by medically trained personnel, such as doctors and nurses, who support the with-drawal management. Medications are often used.
Crisis management
There may be times when people who have concurrent disorders are in crisis. For example, the loss of a loved one, loss of housing, financial hardships or unforeseen violence can lead to a crisis.
It can be very hard for individuals to cope effectively with a sudden crisis. It is useful to plan some emergency strategies when the person is well. For example, before a crisis, the client could create a list of behaviours that can act as warning signs, signalling to them that they should reach out to their support system or to professional/ medical support. This allows everyone to be prepared if anything does happen.
Depending on the situation, a crisis may resolve on its own or be managed at home with family, peer and professional support. Sometimes, a person may need to be hospitalized because of a crisis. After the crisis has passed, a person’s treatment approach may need to change or they may need to access previous supports or treatments, such as counselling and therapy.
Hospitalization
A crisis may turn into an emergency and some people may need to be hospitalized. This can occur when clients are at risk of serious consequences, due to:
- increased aggression
- increased risk-taking behaviours/more impulsive
- overdosing
- self-harming or suicidal behaviour
- reduced ability to look after their own basic needs.
In such cases, the person may stay in the hospital for a few days up to a few weeks. In hospital, the person receives care from the interdisciplinary team and may attend daily group or individual therapy sessions. Clients should expect to leave the hospital when:
- there is improved functioning
- symptoms have improved
- their recovery goals have been achieved
- they are at a lower risk when compared to admission
- follow-up arrangements are in place.
