Illicit drug use and problematic use in the elderly: is there a case for concern?

Traditionally, the prevalence of illicit and problematic drug use in the elderly was thought to be very low (Abrams and Alexopoulos, 1988; Rosenberg, 1995; Crome and Day, 1999; Simoni-Wastila and Yang, 2006). Indeed, in the most recent British Crime Survey respondents over the age of 59 years were not asked about illicit drug use because previous surveys indicated that less than 1% of those aged 60 years and over had taken illicit drugs in their lifetime (personal communication, Home Office Direct Communications Unit, 2007). The vast majority of epidemiological studies of illicit drug use and problematic use in the elderly are from the U.S.A., although studies from other countries are emerging. These epidemiological studies have either been population-based or of convenience samples. An American population-based study reported life-time prevalence of illicit and problematic drug use in men over the age of 65 years as 2.9% and 0.12% respectively (Anthony and Helzer, 1991); the corresponding figures for women were 0.7% and 0.06% respectively. These figures were considerably lower than those in younger age groups. Another American population-based study reported the prevalence of problematic drug use in males and females over the age of 65 years at one of the three study sites as 0% and 0.2% respectively, and the prevalence was zero in both sexes at the other two sites (Myers et al., 1984); however, data on illicit and licit drug problematic use were not reported separately. Other American studies, whilst reporting the prevalence of problematic drug use, failed to differentiate between alcohol and other substances or between illicit and licit drugs (Myers et al., 1984; Burke et al., 1990; Huang et al., 2006). An Australian population-based study reported that 0.1% of females over the age of 65 years had drug-use disorder with opiates (Lynskey et al., 2003); but this was not observed in elderly men, and there were no cases of drug use disorders due to stimulants and cannabis in the elderly in both sexes. Another Australian population-based study of illicit drug use reported that 3% and 0.5% of women over the age of 65 years used cannabis and barbiturates respectively (Hancock et al., 1992); but there were no cases of use of amphetamines, hallucinogens, cocaine and opiates. The same study reported that 2.8% and 1% of men over the age of 65 years used cannabis and opiates; but there were no cases of use of amphetamines, hallucinogens and cocaine. The 2006/2007 British Crime Survey, using a representative samples of private households, reported the following in 50–59 year olds: 0.4%, 12.8% and 3.1% had ever used heroin,