Polysubstance-Related Disorders

Drug use, abuse, and dependence are worldwide problems affecting people of all ages, from children to older adults. In 2014, the National Institute of Drug Abuse reported annual costs of tobacco, alcohol, and illicit drugs reaching more than $700 billion due to health care, lost work productivity, and crime-related expenses. In 2007, the estimated number of individuals in the United States in need of treatment for illicit drug use or alcohol problems was approximately 23.2 million. However, the majority of drug users do not use only one drug. Many use multiple drugs at the same time or at different time points. This pattern has been termed polydrug or polysubstance abuse.

A polydrug user is defined as an individual whose drug-taking behavior involves the abuse of two ...