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Drug use and drug use disorders interfere with the normal, healthy functioning across the lifespan but are fundamentally preventable. In considering the opportunities for preventing drug use and drug disorders, it is important to consider that the initiation of drug use, a necessary precursor to drug disorders, is in most cases a voluntary activity. However, the onset of drug disorders (namely abuse and dependence) is much more dependent on genetic variation in combination with specific environmental factors. The onset of drug use is most common during the late childhood and adolescent years. Proximal and distal biological, psychological, social, and environmental precursors originating as early as the prenatal period play a large role in whether experimentation occurs and use persists. On the other hand, for some individuals, the initiation of drug misuse and illicit use of drugs extends well beyond adolescence into adulthood, even in late adulthood. What follows is a review of basic information about drug use and drug use disorders and a review of prevention opportunities.
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PHARMACOLOGY OF DRUGS OF ABUSE
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An understanding of the pharmacological properties of drugs is essential to the understanding of the development of drug abuse and dependence and hence the design of prevention interventions. Four processes are important to the development of drug abuse and dependence: (a) exposure, including timing of exposure and genetic susceptibility; (b) physical dependence, an adaptive state that manifests itself as intense physical disturbance when drug use is suspended; (c) psychological dependence (or “addiction”), a condition under which there is a drive toward periodic or continuous administration of the drug to produce pleasure or avoid discomfit; and (d) tolerance, or the need for increasingly higher doses of a drug to recapture the original effects of the drug. Drug abuse may occur as the result of exposure only, as in the case of binge drinking on the first occasion of alcohol use or driving a vehicle under the influence of an illicit drug.
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Processes of abuse and dependence reflect characteristics of the drug, the individual user and the context of use. Among the goals of psychopharmacology, epidemiology and etiology research is to gain a better understanding of the processes implicated in the development of dependence based on the drug, the user and their interactions with one another. For example, initial use of a psychoactive drug often results in a pleasurable response. This response is reinforcing or rewarding leading to the desire to use the substance again, thereby maintaining the behavior. The more reinforcing the drug is the more likely the individual will seek the drug and abuse it. This characteristic of the drug is called its abuse liability and has been assessed for numerous drugs through animal self-administration research. In most cases, this research has shown strong correlations between drugs animals will self administer and those that humans will abuse. In other cases, animals will not self administer drugs humans use, ...