Substance Use Trends Among Age Groups: Results from the 1994 through 2015 NSDUH

Background and Purpose: Demographic and substance use changes in the United States have led to a large increase in the overall population of older adult substance users. Estimates of the magnitude of these changes have previously been made, however little follow-up has been given regarding the accuracy of these estimates using current data. This study examines trends in substance use among different age groups, with a focus on the generation known as the baby boomers, or those aging past 50 years old beginning in 2010.

Methods: Data for this study come from multiple years of the National Survey on Drug Use and Health from 1994 through 2015. Age group categories were formed to compare the use trends among individuals aged 18 – 25, 26 – 35, 36 – 49, and 50+. Next, annual trends were examined by regressing year on substance use variables, including alcohol use days, binge drinking days, marijuana use in past month, cocaine use in past month, prescription drug misuse in past month, and treatment utilization in past year. Finally, findings from the current study were used to project substance use behaviors out to the year 2020.

Results: Overall substance use levels showed significant annual increase across all measures except for cocaine use. The older adult age group (50+) had the largest percentage increase across all substance use types between the years 1994 and 2015, with a 22.2% increase in past month alcohol use, a 100% increase in the past month binge drinking, a 375% increase in past month marijuana use, a 50% increase in past month cocaine use, and a 200% increase in past month prescription drug misuse. Projections for the year 2020 had estimated that 2.9% (SE: 0.7) of adults over 50 will have used marijuana in the past year. However, results from this study indicated that the actual number in 2015 was already 6.3% of older adults (SE: 0.26). Additionally, prescription drug projections estimated that 2.4% adults 50 and over will have misused prescription drugs in the past year, while data from the 2015 NSDUH show that already 3.7% (SE: 0.20) of older adults misused prescription drugs in the past year. 

Conclusions and Implications: Older adults are consuming alcohol, prescription and illegal drugs at higher levels than ever before, with 2015 rates for marijuana and prescription drug misuse already exceeding past projections for the year 2020. As these increases grow, social work practitioners will benefit from knowledge and preparation as older adults are the least likely group to be screened for substance use or perceive a need for treatment, suggesting it is likely that a larger portion of America’s population will have increased health vulnerabilities due to unmet substance use treatment needs among older adults. Additionally, relatively little is known regarding the long-term effects of continued substance use throughout older adulthood, especially among marijuana and prescription drug misuse which showed the highest levels of increase in this study.