Substance abuse in the United States: findings from recent epidemiologic studies.

Recent research on the epidemiology of substance use disorders (SUDs) has provided important insights into these conditions and their impact on public health. In the United States, annual surveys of drug use in household and school populations serve as one of the primary sources of information about the distribution of illicit drug use. This research has demonstrated continued shifts in trends in illicit drug use in the United States and called attention to rising rates of prescription drug misuse and abuse. Findings have also continued to highlight the substantial comorbidity of SUDs with other psychiatric disorders and with the ongoing HIV epidemic. Building on these foundations, future challenges for research in substance abuse epidemiology will include using novel methodologic approaches to further unravel the complex interrelationships that link individual vulnerabilities for SUDs, including genetic factors, with social and environmental risk factors.

Prevalence, correlates, disability, and comorbidity of DSM-IV drug abuse and dependence in the United States: results from the national epidemiologic survey on alcohol and related conditions.

BACKGROUND: Current and comprehensive information on the epidemiology of DSM-IV 12-month and lifetime drug use disorders in the United States has not been available. OBJECTIVES: To present detailed information on drug abuse and dependence prevalence, correlates, and comorbidity with other Axis I and II disorders. DESIGN, SETTING, AND PARTICIPANTS: Face-to-face interviews using the Alcohol Use Disorder and Associated Disabilities Interview Schedule of the National Institute on Alcohol Abuse and Alcoholism in a large representative sample of US adults (N=43093). MAIN OUTCOME MEASURES: Twelve-month and lifetime prevalence of drug abuse and dependence and the associated correlates, treatment rates, disability, and comorbidity with other Axis I and II disorders. RESULTS: Prevalences of 12-month and lifetime drug abuse (1.4% and 7.7%, respectively) exceeded rates of drug dependence (0.6% and 2.6%, respectively). Rates of abuse and dependence were generally greater among men, Native Americans, respondents aged 18 to 44 years, those of lower socioeconomic status, those residing in the West, and those who were never married or widowed, separated, or divorced (all P<.05). Associations of drug use disorders with other substance use disorders and antisocial personality disorder were diminished but remained strong when we controlled for psychiatric disorders. Dependence associations with most mood disorders and generalized anxiety disorder also remained significant. Lifetime treatment- or help-seeking behavior was uncommon (8.1%, abuse; 37.9%, dependence) and was not associated with sociodemographic characteristics but was associated with psychiatric comorbidity. CONCLUSIONS: Most individuals with drug use disorders have never been treated, and treatment disparities exist among those at high risk, despite substantial disability and comorbidity. Comorbidity of drug use disorders with other substance use disorders and antisocial personality disorder, as well as dependence with mood disorders and generalized anxiety disorder, appears to be due in part to unique factors underlying each pair of these disorders studied. The persistence of low treatment rates despite the availability of effective treatments indicates the need for vigorous educational efforts for the public and professionals.

Developments in the epidemiology of drug use and drug use disorders.

The past 30 years of research on the epidemiology of drug use, drug use disorders, and related conditions, such as HIV, has provided major insight into these conditions. Drug use peaked in the late 1970s, decreased across the 1980s, increased in the 1990s, and has remained stable during the past few years. Within this broad pattern, specific epidemics of crack cocaine, amphetamines, club drugs (such as Ecstasy), heroin, and prescription opioids and associated epidemics of HIV and other infectious diseases have been identified and tracked. Besides major accomplishments in surveillance, the epidemiology of drug use and drug use disorders has traditionally focused on identifying risk factors at the individual (genetic factors, high-risk behaviors), family (child abuse), neighborhood (high availability of drugs), and societal (policies and laws) levels as domains of influence, not as components of interrelated processes. Research includes careful cross-sectional and longitudinal observational studies as well as clinical epidemiological experiments in which prevention interventions test specific etiological theories. Building on this background, the next challenges for the epidemiology of drug use and drug use disorders will be to link individual vulnerabilities with specific environmental factors by using multilevel methodological approaches. For example, what are the environmental factors that interact with individual vulnerabilities to produce drug addictions and drug consequences such as HIV? Research in genetic epidemiology has demonstrated the potential for studies of interactions of genetic and environmental factors. The field needs to focus on linking science with epidemiology to make progress in understanding these complex health conditions.