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-demographic 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 20/10 g alcohol per day in men/women, respectively) to perform better than abstainers, occasional drinkers or those drinking at hazardous/harmful levels (> 40/20 g 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.