Policymakers are increasingly focused on justice system interactions with and outcomes for people with either mental illness or substance use disorders.1 What has received less attention, however, is the extent to which people with co-occurring mental health and substance use disorders (hereafter called co-occurring disorders) become involved with the justice system.
To better understand this issue at the point of arrest, which is the “front door” of the criminal legal system, The Pew Charitable Trusts analyzed data from 2017 to 2019 from the National Survey on Drug Use and Health (NSDUH).2 NSDUH is an annual, nationally representative, self-reported survey and the only national data source for trends in the incidence and treatment of behavioral health (which includes mental illness and substance use disorders). The survey also asks respondents whether they were arrested in the past year and, if so, how often.
Pew’s analysis found that adults reporting co-occurring serious or moderate mental illness (hereafter “mental illness”) and substance use disorders in the past year were far more likely to be arrested compared with both those with mental illness alone and those who didn’t experience any mental illness or substance use disorder as defined by NSDUH.
People with co-occurring disorders were also unlikely to receive treatment for more than one disorder, even though research demonstrates that simultaneous, coordinated treatment for multiple diagnoses produces better outcomes compared with separate treatment for only mental illness or substance use disorder.3
About 60% of people with a mental illness who were arrested had a co-occurring substance use disorder. NSDUH doesn’t explicitly ask respondents whether these arrests resulted in time spent in jail, so recent national level data on how many of these arrests led to incarceration is not available. Being arrested and jailed can negatively affect wages, employment, housing stability, physical and mental health, and public safety outcomes, including increasing the likelihood of recidivism.4
Researchers have found that communities with more treatment availability may have lower crime and jail incarceration rates, and some jurisdictions are working to divert people with mental illness away from the criminal legal system and into a continuum of community-based care.5 However, an increased focus on the needs of people with co-occurring disorders—particularly on integrated treatment for both mental illness and substance use—could make an even larger impact on the number of people entering and cycling back through the justice system.6
Adults (ages 18 and older) with past-year co-occurring mental illness and substance use disorder represented about 2% of the population but made up 15% of all adults who reported being arrested in the past year. Those with a mental illness alone made up a similar share of the adult population in general and of those arrested (8% and 9%, respectively). Most adults with a mental illness who were arrested had a co-occurring disorder (60%). Although not shown in the chart, Pew analysis also revealed that adults with co-occurring disorders made up an even larger share (18%) of all those arrested twice or more in a year.
About 650,000 adults with co-occurring disorders were arrested annually in the years 2017-19. This was more than 1 in 9 of all adults with co-occurring disorders. In contrast, about 1 in 50 adults with mental illness but no co-occurring substance use disorder and about 1 in 100 adults with no behavioral health issues—that is, neither a substance use disorder nor a mental illness—reported a past-year arrest. People with co-occurring disorders were roughly six times more likely to be arrested annually as those with a mental illness alone, and 12 times more likely to be arrested than those with neither a mental illness nor substance use disorder.
For adults with co-occurring disorders, almost half (48%) of those arrested had a drug-related charge but no additional, more serious charge. Only 10% of adults with co-occurring disorders were arrested for a violent offense as the most serious charge. Additionally, 17% of adults with co-occurring disorders were arrested for a property offense.
Individuals responding to the NSDUH indicate which substances are involved in their disorder. In looking at adults with co-occurring disorders, those who reported a methamphetamine use disorder—either alone or in combination with other substances—were the ones most likely to be arrested. Almost 4 in 10 adults with co-occurring disorders involving a meth use disorder were arrested annually. For all substances except alcohol, most of those arrested had multiple substance use disorders—that is, disorders involving two or more substances.
These results are in line with other recent Pew research, showing the large and growing issue of people using, being arrested for, and dying from meth use.7
Overall, about 2 in 3 (66%) people with co-occurring disorders report that they have an alcohol use disorder. They make up more than half (53%) of all arrests of those with co-occurring disorders due to their overall greater number, even though, as the figure shows, a smaller share are arrested, likely because alcohol is legal for adults to buy and use.
Adult women with co-occurring disorders were almost 20 times more likely to be arrested each year compared with women with no substance use disorder or mental illness. Additionally, they made up more than 1 in 5 (22%) of all adult women arrested (not shown in chart). By comparison, adult men with co-occurring disorders made up 12% of all men arrested.
People with co-occurring disorders frequently report violent victimizations.8 Women are two to three times more likely than men to develop post-traumatic stress disorder and are exposed to more highly traumatic events such as sexual abuse, and at a younger age.9 Research shows that women in jail with a co-occurring disorder were more likely to have a history of trauma than those women with substance use disorders alone, suggesting the need for trauma-centered interventions to reduce arrests and incarceration.10
Black adults with co-occurring disorders were arrested at higher rates than their non-Hispanic White or Hispanic counterparts. About 16% of Black adults with co-occurring disorders were arrested annually versus 11% of White and Hispanic adults with co-occurring disorders. (The sample size of other races was too small to report on with confidence.)
Racial and ethnic disparities in arrests among adults with co-occurring disorders were smaller than for those without behavioral health disorders. Black adults without mental illness or substance use disorder were about three times as likely as their White counterparts to be arrested, while Black adults with co-occurring disorders were about 1.5 times as likely to be arrested as White adults with co-occurring disorders.
Relatively few people with co-occurring disorders received treatment for both their mental illness and substance use disorder. Research shows that integrated treatment—which addresses both mental illness and substance use disorder diagnoses and symptoms at the same time within one coordinated service system and set of providers—produces consistently better outcomes compared with separate treatment of each diagnosis or for treatment of only one disorder.11
White adults with co-occurring disorders were the most likely to indicate that they received treatment (as identified in the survey), with almost 2 of 3 (64%) receiving treatment for substance use disorder, mental illness, or both in the past year. Slightly less than half (47%) of Black adults with co-occurring disorders received treatment of any kind, while an even smaller percentage (43%) of Hispanic adults with co-occurring disorders received treatment.
As this analysis showed, adults with co-occurring disorders in the United States from 2017 to 2019 were over-arrested and undertreated. Given that 60% of those who are arrested with mental illness also have co-occurring substance use disorder, focusing on this intersection is important for both policy and practice. In fact, this analysis found that adults with co-occurring disorders were more likely to be involved with the justice system than those with mental illness alone, and few received treatment for both substance use and mental illness. Implementing evidence-based solutions that increase and improve treatment for co-occurring disorders could reduce justice system contact and produce better public health outcomes for those with co-occurring disorders.
This brief analyzes self-reported survey data taken by the National Survey on Drug Use and Health (NSDUH) from 2017 to 2019.12 Pew looked at survey results from multiple years to ensure adequate data sample sizes for analysis. Data from 2020 was available at the time of publication but excluded from this report because NSDUH switched to new definitions that were not comparable to the previous year’s data sets.13 NSDUH asked respondents if they were arrested and booked within the past year, and while being booked is often construed to mean going to jail, NSDUH does not survey people in jail or prison or in inpatient residential treatment programs or psychiatric hospitals, so this analysis of arrest rates for adults with co-occurring disorders is likely an undercount. The definition of mental illness is adopted from NSDUH, which states that “adults aged 18 or older were classified as having any mental illness if they had any mental, behavioral, or emotional disorder in the past year of sufficient duration to meet Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria (excluding developmental disorders and substance use disorders).” The definition of substance use disorder is adopted from NSDUH and is “characterized by impairment caused by the recurrent use of alcohol or other drugs (or both), including health problems, disability, and failure to meet major responsibilities at work, school, or home … based on criteria specified in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV).” The definition of illicit drugs is adopted from NSDUH and includes “marijuana, cocaine (including crack), heroin, hallucinogens, inhalants, and methamphetamine, as well as for the misuse of prescription stimulants, tranquilizers, sedatives, and pain relievers.”
Pew considered individuals as having a mental illness if they were classified by NSDUH as having a serious or moderate mental illness in the past 12 months; classifications are based on respondents’ self-reported answers and the criteria specified in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). People whose responses indicated that they had a mild mental illness were included in groups identified as not having a behavioral health disorder. Those identified as having a co-occurring disorder were identified as having both a mental illness (serious or moderate) and a substance use disorder, as classified by NSDUH. NSDUH data shows that an additional 300,000 adults with co-occurring mild mental illness and substance use disorder were arrested each year, though they were not included in this analysis. Although a mild mental illness is defined as having only a mild impact on a person’s functionality, research indicates that treatment can prevent the development of more serious mental illness.14