The Connection Between Substance Use Disorder and Mental Illness

From National Institute on Drug Abuse

Many individuals who develop substance use disorders (SUD) are also diagnosed with mental disorders, and vice versa. Multiple national population surveys have found that about half of those who experience a mental illness during their lives will also experience a substance use disorder and vice versa. Although there are fewer studies on comorbidity among youth, research suggests that adolescents with substance use disorders also have high rates of co-occurring mental illness; over 60 percent of adolescents in community-based substance use disorder treatment programs also meet diagnostic criteria for another mental illness.

Data show high rates of co-morbid substance use disorders and anxiety disorders—which include generalized anxiety disorder, panic disorder, and post-traumatic stress disorder. Substance use disorders also co-occur at high prevalence with mental disorders, such as depression and bipolar disorder, attention-deficit hyperactivity disorder (ADHD), psychotic illness, borderline personality disorder, and antisocial personality disorder.

Patients with schizophrenia have higher rates of alcohol, tobacco, and drug use disorders than the general population. As Figure 1 shows, the overlap is especially pronounced with serious mental illness (SMI). Serious mental illness among people ages 18 and older is defined at the federal level as having, at any time during the past year, a diagnosable mental, behavior, or emotional disorder that causes serious functional impairment that substantially interferes with or limits one or more major life activities. Serious mental illnesses include major depression, schizophrenia, and bipolar disorder, and other mental disorders that cause serious impairment. Around 1 in 4 individuals with SMI also have an SUD.

Data from a large nationally representative sample suggested that people with mental, personality, and substance use disorders were at increased risk for non-medical use of prescription opioids. Research indicates that 43 percent of people in SUD treatment for non-medical use of prescription painkillers have a diagnosis or symptoms of mental health disorders, particularly depression and anxiety.

Source: NIDA. 2020, May 28. Part 1: The Connection Between Substance Use Disorders and Mental Illness. Retrieved from https://www.drugabuse.gov/publications/research-reports/common-comorbidities-substance-use-disorders/part-1-connection-between-substance-use-disorders-mental-illness on 2020, October 8.