When a substance use disorder and a mental health disorder happen in the same person, clinicians call this a co-occurring disorder, or sometimes a dual diagnosis. These conditions are common; they often influence each other, and they can make both diagnosis and treatment more complex. If you or a loved one is facing this, integrated addiction therapy that addresses both within one coordinated plan tends to work better than treating either one alone.
A co-occurring disorder involves substance use and one or more mental health conditions together. Older national population studies suggest that about half of people who experience a mental illness during their lives will also experience a substance use disorder at some point, and the reverse is also true [1]. This is a lifetime estimate rather than a current annual rate, but it shows why substance use disorders and mental illnesses are often described as deeply intertwined rather than separate problems. Our mental health and addiction treatment addresses the mental health side alongside the substance use.
This article explains common co-occurring disorders, why they occur together, and how treatment can help. It is education, not medical advice, and a qualified professional is the right person to make a diagnosis.
Why Substance Use and Mental Illness Occur Together
Substance use disorders and mental health disorders share many of the same risk factors, including genetics, environmental factors, and exposure to stress or trauma, which is one reason they occur together so often [2]. Having a mental illness may increase vulnerability to substance misuse, while intoxication, withdrawal, and repeated substance use can trigger or worsen psychiatric symptoms in some people. In other cases, both conditions arise partly from shared risk factors, so the relationship is not a simple one-way street.
Self-medication is one possible pathway. A person may self-medicate, using drugs or alcohol to cope with difficult feelings, only to find that temporary relief is followed by rebound symptoms, withdrawal, or impaired sleep that make things harder over time. This does not describe everyone, and it is one explanation among several. To go deeper on this, our article on trauma and addiction and our overview of the underlying reasons for addiction are helpful.
For related reading, our understanding addiction guide hub gathers connected articles in one place.
Common Mental Health Disorders That Co-Occur With Addiction
No single combination defines co-occurring disorders, and prevalence varies by substance, population, age, sex, and treatment setting. Commonly reported co-occurring conditions include depression, anxiety disorders, PTSD, bipolar disorder, psychotic disorders, ADHD, certain personality disorders, and eating disorders. The table below summarizes several of them, and it is not an exhaustive list.
| Mental health condition | How it often relates to substance use |
|---|---|
| Depression | Depressive symptoms are common with alcohol use disorder, and each can worsen the other |
| Anxiety disorders | Anxiety and alcohol use disorder frequently co-occur, sometimes through attempts to self-medicate |
| Post-traumatic stress disorder | PTSD often co-occurs with substance use, and substances may be used to manage symptoms |
| Bipolar disorder | People with bipolar disorder often experience co-occurring substance misuse |
| Eating disorders | Eating disorders can co-occur with substance use |
Depression and Major Depressive Disorder
Depression is one of the mental health conditions most often seen with addiction, especially alcohol use disorder. Depressive symptoms and drinking commonly go together, and the combination is linked with greater severity and a worse outlook for both conditions unless both are addressed. An independent major depressive disorder may precede or coexist with substance use, while intoxication or withdrawal can also produce depressive symptoms or a substance-induced depressive disorder. Careful assessment, including a timeline of when symptoms began and whether they persist in recovery, is needed to tell these possibilities apart.
Anxiety Disorders
Anxiety disorders are among the most common mental health conditions overall, and they occur at elevated rates among people with substance use. This group includes generalized anxiety disorder, panic disorder, and agoraphobia, among others. Exact estimates vary by diagnosis and treatment setting. Some people drink or use other drugs in an attempt to manage intense fear or worry, though substance use and withdrawal can also intensify anxiety over time.
Post-Traumatic Stress Disorder
Post-traumatic stress disorder often co-occurs with substance use disorders. People with PTSD may use alcohol or other drugs to cope with intrusive memories, hyperarousal, or sleep problems, and substance use may also increase exposure to accidents, violence, or other potentially traumatic events. Because the two are so connected, screening for substance use when PTSD is present, and for PTSD when a substance use disorder is present, supports good treatment planning.
Bipolar Disorder
Individuals with bipolar disorder often experience co-occurring substance misuse. Possible contributors include attempts to cope with symptoms, impulsivity or reward seeking during manic episodes, and shared risk factors. Careful diagnosis matters here, since substance use can mimic or precipitate mood symptoms, so clinicians look at the timing and persistence of symptoms.
Other Conditions
Other mental health disorders can co-occur with addiction too. Schizophrenia-spectrum and other psychotic disorders, which may involve hallucinations, delusions, or disorganized thinking, occur with substance use at elevated rates, and a primary psychotic disorder needs to be distinguished from substance-induced psychosis. Attention-deficit concerns are also relevant, since adults with ADHD have higher rates of substance use disorders than adults without it, likely through a mix of shared risk factors, impulsivity, and functional difficulties. Eating disorders can co-occur with substance use as well, and patterns differ by diagnosis, sex, and population, so this overlap is best assessed individually.
Why Co-Occurring Disorders Are Harder to Treat
Co-occurring disorders increase the difficulty of both diagnosis and treatment, partly because symptoms overlap and can be hard to disentangle. People who have both a substance use disorder and another mental illness often have symptoms that are more persistent and severe, may have more difficulty staying in treatment, and can experience greater functional impairment than with either condition alone [3]. When a significant condition goes unrecognized or untreated, it can undermine recovery, which is a strong argument for addressing both together. Our guides on 10 signs you may need dual diagnosis treatment and whether addiction is a mental disorder expand on this, and the distinction between comorbid and co-occurrence is worth understanding.
Left unaddressed, co-occurring disorders can also raise the risk of suicidal thoughts and behaviors, especially when depression, PTSD, or a history of prior attempts is present, which is one more reason to seek professional help rather than trying to manage them alone.
Treating Co-Occurring Disorders
The good news is that co-occurring disorders are treatable. Research supports integrated treatment, which coordinates evidence-based care for the mental health disorder and the substance use disorder within one plan rather than treating them in isolation [4]. The specific treatments may differ for each diagnosis, and a comprehensive plan is built around the individual and the substances involved. It may include several of the following:
- Behavioral therapies such as cognitive behavioral therapy, chosen according to the person’s specific diagnoses
- Medication when appropriate, chosen for the person’s conditions; for example, different bupropion products are FDA-approved for major depressive disorder and for smoking cessation, though formulation, contraindications, and individual risks must be reviewed by a prescriber
- Support groups that provide emotional and social support alongside professional care
- Coordinated care from a therapist and medical team who work together
Detox may be an early step when physical dependence is involved, though its length varies by substance and the person; it is not required in every case, and it is only the beginning rather than the whole of treatment. From there, ongoing therapy and support help a person build a durable recovery. If you are unsure where to begin, our guide on signs you need to seek help for addiction and our article on the importance of family education for addiction treatment are useful starting points, and professional addiction treatment can bring these pieces together. For families, our guide on how to know if your loved one is using drugs can also help.
Most Common Co-Occurring Disorders Frequently Asked Questions
What is a co-occurring disorder?
A co-occurring disorder means a person has at least one substance use disorder and at least one mental health disorder at the same time. It is also called a dual diagnosis, though a person may have more than two conditions. The conditions can influence each other, which is why treating them together is generally recommended.
How common are co-occurring disorders?
They are common. Older national studies suggest that about half of people who experience a mental illness during their lifetime will also experience a substance use disorder at some point, and the reverse is true as well. Annual estimates are lower because they measure both conditions within the same 12-month period, but they still represent millions of U.S. adults.
Can co-occurring disorders be treated at the same time?
Yes, and for many people that is the preferred approach. Integrated treatment addresses the mental health disorder and the substance use disorder within one coordinated plan, which tends to produce better outcomes than treating one and ignoring the other. The exact timing, therapies, and level of care should be tailored by a qualified professional.
Sources
- National Institute on Drug Abuse (NIDA), Comorbidity: Substance Use Disorders and Other Mental Illnesses DrugFacts: https://nida.nih.gov/publications/drugfacts/comorbidity-substance-use-disorders-other-mental-illnesses
- National Institute on Drug Abuse (NIDA), Common Comorbidities with Substance Use Disorders Research Report (NCBI Bookshelf): https://www.ncbi.nlm.nih.gov/books/NBK571451/
- Substance Abuse and Mental Health Services Administration (SAMHSA), Co-Occurring Disorders and Other Health Conditions: https://www.samhsa.gov/substance-use/treatment/co-occurring-disorders
- National Institute on Drug Abuse (NIDA), Co-Occurring Disorders and Health Conditions: https://nida.nih.gov/research-topics/co-occurring-disorders-health-conditions
