Participants were asked in waves 1–4 to report the highest number of drinks they had ever consumed in a 24-h period, with response options ranging from 1 to 24, plus “more than 24.” They could also opt not to answer or select “I don't know,” both of which were recoded as missing for the current analyses. Data were available for 6,125 participants. We selected the highest reported Maxdrinks for each individual, as well as the participant's age at that report for inclusion as a covariate in genetic analyses.
