Another alcoholism-related trait assessed in the COGA study was the maximum number of drinks a person ever consumed in a 24-hour period, which was determined based on the participants’ response to the question, “What is the largest number of drinks you have ever had in a 24-hour period?” (Saccone et al. 2000). The examination of this variable was motivated by twin studies that demonstrated a moderate genetic influence on the maximum number of drinks a person consumes in 24 hours. The COGA investigators found a significant association in the study participants between the maximum number of drinks consumed and the risk of developing alcoholism. Thus, none of the participants who reported drinking a maximum of 2 drinks within a 24-hour period exhibited any symptoms of problem drinking. However, the rate of alcoholism increased with increasing maximum amounts of alcohol consumption in a 24-hour period. For instance, among participants who reported drinking 9 or more drinks in a 24-hour period, 65 percent of men and 53 percent of women were diagnosed with alcohol dependence.
