The Substance Abuse Screening & Subtle Inventory Assessment (SASSI-4) identifies high or low probability of substance use disorders and includes a prescription drug scale that identifies individuals likely to be abusing prescription medications. Objective decesions rules classify individuals as chemically dependent or as not chemically dependent. Identify early-stage chemically dependent individuals who are either in denial or who are trying to conceal their chemical dependency. In addition to being used as a screening instrument, the SASSI-4 also provides clinical insights into a respondent's defensiveness and willingness to acknowledge experienced consequences of substance use disorder.