Aims: The aim of this paper is to investigate two possible explanations for the higher levels of psychological distress observed among alcohol abstainers relative to light and moderate drinkers, and to investigate possible moderating effects of age on this association. The possible explanations were that: (i) the higher level of psychological distress among abstainers is due to the presence of a subset of former heavy drinkers in this group; and (ii) abstainers have poorer social relationships than light/moderate drinkers. Methods: A national cross-sectional survey yielded data from 2856 Australians aged 20-22, 30-32 and 40-42 years (response rate 15.9%). Results: The sample was representative for many socio-demographic factors but under-represented people not in the labour force and over-represented those with university qualifications. In the oldest but not the younger age groups, abstainers reported significantly higher psychological distress relative to light/moderate drinkers. While abstainers in the oldest age group who were former heavy drinkers showed the highest levels of distress, excluding them from the analysis did not account for differences in distress between current abstainers and light/moderate drinkers. Abstainers aged 40-42 years were less socially integrated, less extraverted and had lower social support than light/moderate drinkers, and controlling for these factors partially explained their increased distress. Conclusions: Significantly increased psychological distress of abstainers compared to light/moderate drinkers was demonstrated only in the oldest age group (40-42 years). The higher distress reported by abstainers in this age group was partially explained by abstainers having poorer social relationships than light/moderate drinkers.