6. Serious Mental Illness among Adults

Serious mental illness (SMI) was first measured by the National Household Survey on Drug Abuse (NHSDA) in 2001 for all persons aged 18 or older. For this report on the 2003 National Survey on Drug Use and Health (NSDUH), SMI is defined as having at some time during the past year a diagnosable mental, behavioral, or emotional disorder that met the criteria specified in the Diagnostic and Statistical Manual of Mental Disorders, 4^th edition (DSM-IV) (American Psychiatric Association [APA], 1994) and resulted in functional impairment that substantially interfered with or limited one of more major life activities. For additional information on the SMI measure, see Appendix A of the Office of Applied Studies (OAS, 2004b).

In 2003, SMI was present in 9.2 percent of the population aged 18 or older, significantly higher than the 8.3 percent in 2002 (OAS, 2004c, Table 6.1B). In 2002–2003, 8.8 percent of the population aged 18 or older was identified as having SMI (Table B.21). The States with the highest rates of SMI in 2002–2003 were mostly in the South (Arkansas, Kentucky, Oklahoma, and West Virginia) or in the West (Idaho, Montana, Utah, and Washington). Rhode Island had the highest rate in the Nation for SMI among persons aged 18 or older (11.0 percent), and Hawaii had the lowest rate in the Nation (7.2 percent) (Table B.21, Figure 6.1).

At the individual level, SMI has been associated with the use of illicit drugs and smoking cigarettes, as well as with other characteristics, such as educational status, unemployment, and urbanicity (OAS, 2004b). At the State level, estimates of SMI were compared with estimates of various substance use measures to determine the degree of correlation with those measures. Although SMI is somewhat correlated at the individual level with past month use of an illicit drug, the correlation at the State level among persons aged 18 or older was fairly low (0.11). The correlation at the State level between SMI and past month use of cigarettes was slightly higher (0.27). This finding is consistent with literature that shows some correlation at the individual level between smoking cigarettes and SMI (Arday et al., 1995; Kessler et al., 2003; Romans, McNoe, Herbison, Walton, & Mullen, 1993; Woolf, Rothemich, Johnson, & Marsland, 1999). The State-level correlations between SMI and dependence on or abuse of drugs or need for treatment also are quite low. The correlation at the State level between SMI and the 2000 per capita income was negative and quite high (-0.47); the lower the income of the State, the higher the percentage with SMI.

Figure 6.1 Serious Mental Illness in Past Year among Persons Aged 18 or Older, by State: Percentages, Annual Averages Based on 2002 and 2003 NSDUHs

Figure 6.1 D

Source: SAMHSA, Office of Applied Studies, National Survey on Drug Use and Health, 2002 and 2003.

Figure 6.2 Serious Mental Illness in Past Year among Persons Aged 18 to 25, by State: Percentages, Annual Averages Based on 2002 and 2003 NSDUHs

Figure 6.2 D

Source: SAMHSA, Office of Applied Studies, National Survey on Drug Use and Health, 2002 and 2003.

Figure 6.3 Serious Mental Illness in Past Year among Persons Aged 26 or Older, by State: Percentages, Annual Averages Based on 2002 and 2003 NSDUHs

Figure 6.3 D

Source: SAMHSA, Office of Applied Studies, National Survey on Drug Use and Health, 2002 and 2003.