Non-linear relationships between cognitive function and alcohol consumption in young, middle-aged and older adults: The PATH through life project

Aims: To investigate associations, including non-linear relationships, between cognitive function and alcohol consumption, testing for moderating effects of age and gender and for differences across outcome measures. Design: Cross-sectional general population samples of three age cohorts. Setting: Canberra and Queanbeyan, Australia. Participants: The total sample of 7485 consisted of 2404 men and women aged 20-24 years, 2530 aged 40-44 years, and 2551 aged 60-64 years, selected from the electoral rolls. Measurements: Self-report data using hand-held computers provided weekly alcohol consumption from the Alcohol Use Disorders Identification Test (AUDIT) frequency, quantity and binge-drinking items, and socio-emographic factors. Spot-the-Word, digits backwards, the Symbol-Digit Modalities Test (SDMT), immediate recall and reaction-time tests were conducted by trained interviewers. Findings: Findings varied across dependent variables, but there was a general tendency for light drinkers (up to 20/10g alcohol per day in men/women, respectively) to perform better than abstainers, occasional drinkers or those drinking at hazardous/harmful levels (>40/20g per day in men/women). Poorer performance of hazardous/harmful drinkers was seen only in men, whereas that of abstainers was evident in both sexes but was stronger in women. After adjustment for education and race, male hazardous/harmful drinkers no longer performed significantly less well than light drinkers, whereas male and female abstainers and occasional drinkers still did so. Conclusions: Abstainers have poorer cognitive function than light drinkers and further investigation is needed to determine what factors contribute to this.