^* The need for treatment varies according to the severity of the problem. To reflect these differences, HHS divided those needing treatment into two categories, termed Level 1 and Level 2, based on intensity of drug use, symptoms, and consequences. The more severe category of need is Level 2, meaning the severity of symptoms make these users prime candidates for treatment. Level 2 users correspond to chronic, hardcore users discussed on the National Drug Control Strategy.

Note: Estimates for 1991-98 are ratio-adjusted to partially account for underestimation due to underreporting and undercoverage in the NHSDA. Estimates for 1991-93 are also adjusted for trend consistency to account for the change in the NHSDA questionnaire in 1994. Adjustment factors for trend consistency were 1.19020 for total treatment need and 1.21125 for Level 2 treatment need.

Due to improvements in coverage in the Uniform Facility Data Set (UFDS) in 1998, UFDS counts of clients in treatment are not comparable to earlier counts. Therefore, the 1997 estimate of number treated was used to estimate treatment gap in 1998. This methodology is currently being reviewed by an interagency working group. Treatment need is to be defined based on estimating those diagnosed with drug abuse or dependence according to DSM-IV criteria.

Source: Office of Applied Studies, SAMSHA. Unpublished data from the National Household Survey on Drug Abuse and Uniform Facility Data Set (1991-1998).