A new study funded by the National Institute on Drug Abuse (NIDA) showed that people with severe mental illness (eg, schizophrenia, bipolar disorder) have a higher risk for substance use, especially cigarette smoking.

RELATED: Psychiatric Disorders Resource Center

Data from past studies suggest that people with mood or anxiety disorders are twice as likely to suffer from a substance use disorder compared to the general population. Of the 8.4 million U.S. adults that have both a mental and substance use disorder, 53.7% receive no treatment at all.

In this study, 9,142 people diagnosed with schizophrenia, schizoaffective disorder, or bipolar disorder with psychotic features, and 10,195 matched controls were enrolled. The Diagnostic Interview for Psychosis and Affective Disorder (DI-PAD) was also used for all participants to determine substance use rates.

Study results showed that compared to the general population, people with severe mental illness were:

  • 4 times more likely to be heavy alcohol users (>4 drinks/day)
  • 3.5 times more likely to use marijuana regularly (21 times/year)
  • 4.6 times more likely to use other drugs >10 times in their lives
  • 5.1 times more likely to be daily smokers

Also, certain protective factors, such as belonging to a certain racial or ethnic group or being female, did not exist in participants with severe mental illness.

These findings emphasize the need to improve the understanding of the relationship between substance use and psychotic disorders so that both conditions can be treated effectively.

For more information call (301) 443-1124 or visit DrugAbuse.gov.