Nearly 60% of subjects used alcohol during the past year, 2.6% marijuana, and 0.41% cocaine (other use reported was very rare in this age group). Both alcohol and drug use were more frequently used in subjects 50–64 than in those 65+ years of age. In fact, the prevalence among the 50–64 age group far greater than the 65+ age group, suggesting perhaps that we may be now observing the trend for increased use among the baby boom population as they age predicted by Gfroerer et al.8
We also found drug use more prevalent among males (marijuana and cocaine use) and among those who are not employed (cocaine use).
Drug use, in contrast to alcohol use, was not associated with education and was more common among those not currently married (single, separated, divorced, or widowed), and those with major depression. The prevalence of drug use disorder in the 50+ age group was very low (only 0.33% for any drug abuse/dependence, 0.12% for marijuana abuse/dependence, and 0.18% for cocaine abuse/dependence). Nevertheless, the use of marijuana approached 4% in the 50–64 age group in comparison to 0.7% in the 65+ age group. Subjects who used cocaine were at a far greater risk for abuse/dependence (44%) than for subjects who did not use cocaine, but used alcohol or marijuana.
These findings should be interpreted with some caution. First, the cross-sectional nature of our data precludes drawing causal inference related to the associations we have reported. Second, substance use behaviors are obtained from respondents’ self-reports, which are subject to a variety of biases associated with memory errors and under-reporting. 18
For example, among emergency department patients, excess undeclared drug use was more common in the elderly (65+). 19
Most of the undeclared use (as tested by saliva and urine screens) was for opioids (2.5% vs. 14.4% in females, 2.4 vs. 11.6% in males), benzodiazepines (10.0% vs. 23.7% in females, 4.3 vs. 11.9% in males), stimulants (0.0% vs. 19.8% in females, 0.0 vs. 6.7% in males), and marijuana (no difference in females, 0.7 vs. 2.4 % in males).
Finally, individuals who were institutionalized (e.g., in jails or long-term hospitals) or homeless on the date of the survey, as well as active military personnel, are not covered by the NSDUH sampling. These findings thus do not apply to them and some settings may contain a higher prevalence of drug use than the community. For example, older adults in one study living in public housing had a higher prevalence of substance abuse/dependence than older adults in the general population (4.4% one-month and 23.0% lifetime). 20
In another study of VA mental health inpatients and outpatients, rates of dual diagnosis declined significantly as the age of the respondents increased (26.7% of patients < 65 and 6.9% for those ≥ 65). 21
Even so, among all the mental health patients, 3.7% of the 74+ age group, 5.8% of 65–74 age group, 12.2% of the 55–64 age group, and 11.2% of the under 55 age group had a substance abuse only disorder. Nonetheless, it is worthy noting that previous community-based research has shown that the inclusion of institutionalized individuals in large-scale surveys does not change substantially the overall population estimates of drug use disorders because of the small numbers of individuals in these subgroups relative to the large size of the U.S. household population.1
Despite theses limitations, the NSDUH design has many strengths. The large number of respondents provides one of the largest samples of substance use among late middle aged and elderly subjects living in the community. The response rate is certainly respectable given the current state of community based survey research. The probes assessing use and abuse are quite detailed given the focus of the survey. Finally, the survey used the most advanced audio computer-assisted self-interviewing technology to assess respondents’ substance use behaviors, a technology that has been found to increase reporting of sexual and drug use behaviors 14
In conclusion, data from the NSDUH suggest that the prevalence of drug use among the 65+ age group is very low. However, the much greater prevalence in the 50–64 age group could be a portent of much higher use of these drugs as the baby boom cohort ages. These trends should be watched closely and the availability of yearly NSDUH data makes this possible.