State Estimates of Adult Mental Illness from the 2011 and 2012 National Surveys on Drug Use and Health

Mental illness is a major public health concern in the United States.¹ Information on the prevalence of mental illness is needed to help guide and inform effective treatment and prevention programs. The Substance Abuse and Mental Health Services Administration (SAMHSA) provides block grant funding to States in support of programs and services for adults with mental illness with the goal to improve the life of adults and their capacity to work in their community.²

SAMHSA defines mental illness based on diagnostic criteria in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV).³ Any mental illness (AMI) among adults aged 18 or older is the presence of any mental, behavioral, or emotional disorder in the past year that met DSM-IV criteria. Among adults with a disorder, those adults whose disorder caused substantial functional impairment (i.e., a disorder that substantially interfered with or limited one or more major life activities) are defined as having serious mental illness (SMI) and have the most urgent need for treatment.⁴ In 2012, only 62.9 percent of adults with SMI (6.0 million people) had received mental health treatment nationally in the past 12 months.⁴

This issue of The NSDUH Report presents State-level estimates of SMI based on data collected from approximately 92,400 adults aged 18 or older from the combined 2011 and 2012 National Surveys on Drug Use and Health (NSDUHs).⁵ Estimates are displayed in two tables and on two U.S. maps. In the tables, State estimates are listed alphabetically for easy reference. To produce the maps, State estimates shown to two decimal places were first rank ordered from lowest to highest and then divided into quintiles (fifths).⁶ States with the lowest estimates (i.e., the lowest fifth) are assigned to the bottom quintile and are shown in dark blue. States with the highest estimates are assigned to the top quintile and are shown in dark red. All other States are assigned to one of three quintiles between the lowest and highest quintiles. In some cases, a "quintile" could have more or fewer States than desired because two (or more) States have the same estimate (to two decimal places). When such ties occurred at the "boundary" between two quintiles, all States with the same estimate were assigned to the lower quintile. These estimates are the result of an expanded mental health questionnaire that has provided State estimates of various mental health indicators annually since 2008.⁷

Among adults aged 18 or older, the national rate of SMI was 4.0 percent, which equates to 9.3 million Americans. Among individual States, the percentage of adults aged 18 or older with SMI ranged from 3.1 percent in New Jersey to 5.5 percent in West Virginia (Figure 1, Table 1). New Jersey shares the lowest quintile with Hawaii, Illinois, and Connecticut (at 3.2 percent each); Maryland (3.3 percent); and the District of Columbia (3.4 percent). The remaining States in the lowest quintile for SMI are Louisiana, New York, California, and Georgia. Along with West Virginia, States with the highest SMI rates include Oklahoma (5.2 percent), along with Utah, Washington, and Arkansas (each with a rate of 5.1 percent). Kentucky, Vermont, New Mexico, Mississippi, and Idaho make up the rest of the States in the top quintile. States with high and low rates of SMI occurred in all regions of the United States, with no notable regional clustering of high and low rates.

Nationally, 42.5 million adults aged 18 or older experienced any mental illness in the past year, corresponding to a rate of 18.2 percent. Among States, AMI rates ranged from 14.7 percent in New Jersey to 22.4 percent in Utah (Figure 2, Table 2). Including New Jersey, States with the lowest rates include Illinois (15.9 percent), Nevada (16.1 percent), Connecticut (16.7 percent), and North Carolina (16.8 percent). Texas, Florida, Minnesota, North Dakota, and Massachusetts complete the list of States in the bottom quintile. Along with Utah, the States with the highest rates include Oklahoma (21.9 percent), West Virginia (21.4 percent), Oregon (20.9 percent), and Washington (20.8 percent). Other States in the top quintile are Idaho, Mississippi, Tennessee, Maine, and Indiana. As with SMI, high and low rates of AMI occurred in all regions of the United States.

Although there is wide variation in the rates of SMI and AMI among States, there were people with SMI and AMI in every State. States with high and low rates of SMI and AMI are located in all regions of the United States. Idaho, Mississippi, Oklahoma, Utah, Washington, and West Virginia had the highest rates for both SMI and AMI. Connecticut, Illinois, and New Jersey had the lowest rates across both measures. The presence of SMI and AMI in every state reinforces that mental illness is a major public health concern in the United States. Factors that potentially contribute to the variation are not well understood and need further study. However, policymakers can use State-level information to help inform their assessments of mental health needs in their communities. As data from a number of years of NSDUHs are accumulated, in-depth analysis of these State-level data will continue to provide insight into the patterns of mental illness, such as variations over time and by age and gender within each State.

NSDUH_170