A problem with samples unselected for consumption, is that low consumption levels may reflect a mixture of biological and social causes, thereby obscuring evidence of genetic influence. Furthermore, in many studies focussed on chronic medical conditions, participants will typically be older, at an age where current drinking patterns may not reflect past heavy use, and recall of lifetime history may be imperfect or unavailable. Nevertheless, characterisation of genetic causes of variation in alcohol use in the general population is important.
