Substance Abuse Disorders

Overview

A substance use disorder (SUD) is a mental disorder that affects a person’s brain and behavior, leading to a person’s inability to control their use of substances such as legal or illegal drugs, alcohol, or medications. Symptoms can range from moderate to severe, with addiction being the most severe form of SUDs.

Researchers have found that about half of individuals who experience a SUD during their lives will also experience a co-occurring mental disorder and vice versa. Co-occurring disorders can include anxiety disorders, depression, attention-deficit hyperactivity disorder (ADHD), bipolar disorder, personality disorders, and schizophrenia, among others. For more information, please see the National Institute on Drug Abuse (NIDA)’s Common Comorbidities with Substance Use Disorders Research Report.

While SUDs and other mental disorders commonly co-occur, that does not mean that one caused the other. Research suggests three possibilities that could explain why SUDs and other mental disorders may occur together:

  • Common risk factors can contribute to both SUDs and other mental disorders. Both SUDs and other mental disorders can run in families, suggesting that certain genes may be a risk factor. Environmental factors, such as stress or trauma, can cause genetic changes that are passed down through generations and may contribute to the development of a mental disorder or a substance use disorder.
  • Mental disorders can contribute to substance use and SUDs. Studies found that people with a mental disorders, such as anxiety, depression, or post-traumatic stress disorder (PTSD), may use drugs or alcohol as a form of self-medication. However, although some drugs may temporarily help with some symptoms of mental disorders, they may make the symptoms worse over time. Additionally, brain changes in people with mental disorders may enhance the rewarding effects of substances, making it more likely they will continue to use the substance.
  • Substance use and SUDs can contribute to the development of other mental disorders. Substance use may trigger changes in brain structure and function that make a person more likely to develop a mental disorder.

Diagnosis and Treatment

Generally, it is better to treat the SUD and the co-occurring mental disorders together rather than separately. Thus, people seeking help for a SUD and other mental disorders need to be evaluated by a health care provider for each disorder. Because it can be challenging to make an accurate diagnosis due to overlapping symptoms, the provider should use comprehensive assessment tools to reduce the chance of a missed diagnosis and provide targeted treatment.

It also is essential that treatment, which may include behavioral therapies and medications, be tailored to an individual’s specific combination of disorders and symptoms, the person’s age, the misused substance, and the specific mental disorder(s). Talk to your health care provider to determine what treatment may be best for you and give the treatment time to work.