Illicit drug use by mothers and their daughters in Australia: A comparison of two generations.

Background: While recent decades have witnessed an increase in the use of illicit drugs in Australia, the extent to which the types of drugs used has changed over a generation of young women has not been documented.

Methods: Data are from a prospective birth cohort study. Mothers were recruited in early pregnancy (1981-83) and then they and their child were followed up, with mothers interviewed 27 years (2008-2011), and daughters 30 years (2010-14), after the birth. At these most recent interviews both mothers and daughters were administered the Composite International Diagnostic Interview (CIDI III). Comparisons are for mothers and daughters separated by a 25 year period. For this study, we compare levels of lifetime use of a range of illicit drugs and drug use disorders reported by mothers and their daughters (N = 998 mother/daughter pairs) with adjustment for family income, marital status, education and occupation.

Results: There has been a generational increase in the use of illicit substances and prevalence of substance use disorders experienced by Australian women. Mothers' use of illicit drugs was generally restricted to cannabis. By contrast the majority of daughters report lifetime use of an illicit drug with cannabis, club drugs and stimulants the most common. Compared to the mothers, daughters used club drugs 50 times, cocaine 19 times and inhalants 20 times more often. Daughters report experiencing 12 times the rate of cocaine use disorders, 9 times the rate of stimulant disorders and 7 times the rate of cannabis use disorders compared to their mothers.

Conclusions: Mothers of the current generation of 30 year old Australian women rarely used illicit drugs and few experienced a drug use disorder. The current generation of young women report commonly using one or more illicit drugs with a substantial minority experiencing a drug use disorder. It is unlikely that the use of illicit drugs by young women in Australia will be reversed in the foreseeable future. Government policies and treatment practices need to be calibrated to the reality of the much greater contact with illicit drugs being exhibited by younger women.