The Co-occurrence of Nicotine With Other Substance Use and Addiction: Risks, Mechanisms, Consequences, and Implications for Practice, With a Focus on Youth

Nicotine use and addiction frequently co-occur with alcohol and other drug use and addiction in both young people and adults. Studies of the neurobiology of such co-occurrence shed light on the ways in which nicotine primes or sensitizes the brain to be more receptive to the use of other substances and to their addictive effects and the ways in which nicotine and other addictive substance use mutually perpetuate one another through cross reinforcement and cross-tolerance processes. These effects are especially pronounced during youth, when key regions of the brain associated with cognition, emotion, substance use, and addiction are undergoing rapid change and development. The substantial co-occurrence of all forms of nicotine use and other substance use and addiction underscores the need to control the growing use of noncigarette nicotine products, especially among youth, and to incorporate all forms of nicotine product use into substance use and addiction prevention and clinical practice.