"Thirty-day prevalence of alcohol use is also negatively associated with SES [Socio-Economic Status] in 8th grade, but that association declines in upper grades and showing little difference by 12th grade. The prevalence of getting drunk in the prior 30 days is also negatively associated with SES in 8th grade, but becomes positively correlated with SES by 12th grade."
Johnston, L. D., O’Malley, P. M., Bachman, J. G., Schulenberg, J. E. & Miech, R. A. (2014). Monitoring the Future national survey results on drug use, 1975–2013: Volume I, Secondary school students. Ann Arbor: Institute for Social Research, The University of Michigan, p. 103.