Revised Estimates of Mental Illness from the National Survey on Drug Use and Health

The Substance Abuse and Mental Health Services Administration (SAMHSA) has produced national and State estimates of mental illness among adults using its National Survey on Drug Use and Health (NSDUH) since 2008. These model based estimates were based on the 2008 Mental Health Surveillance Study (MHSS); however, given additional years of MHSS data collection, SAMHSA was able to improve to the methods used to produce these estimates. This report summarizes the prediction model of serious mental illness (SMI) that was developed from the clinical subsample of respondents in 2008 and describes how the 2011 NSDUH SMI estimates were revised based on an expanded clinical subsample of about 5,000 completed clinical assessments. While the 2008 model included two predictors (i.e., short scales of psychological distress and impairment), a new model was identified that improved the two-predictor 2008 model by adding three more predictors based on the respondent's age, past year thoughts of suicide, and past year depression. SAMHSA found that estimates based on the improved methods are more similar to the clinical data than estimates based on the 2008 methods, including estimates by age group. Thus, revising the weights and adding new predictors to the model produced more accurate estimations of mental illness.