"Comorbidity of depression and drinking is among the bedrocks of psychiatric epidemiology findings -- until now. Our results suggest that we need to be re-thinking the connections between mental health and alcohol among young people," said Katherine M. Keyes, PhD, associate professor of epidemiology at Columbia Mailman School of Public Health.

Data were drawn from the U.S. nationally representative Monitoring the Future surveys from 1991-2018 for 58,444 school-attending 12th-grade adolescents. Binge drinking was measured as having more than five drinks during the past two weeks. Depressive symptoms were measured based on agreeing or disagreeing with statements that life is meaningless or hopeless.

The relationship between depressive symptoms and binge drinking decreased by 16 percent from 1991 to 2018 and 24 percent among girls and 25 percent among boys. There had been no significant relation between depressive symptoms and binge drinking among boys since 2009; among girls, the relationship has been positive throughout most of the study period.

The results suggest that, on average, the relationship between binge drinking and depressive symptoms is dynamically changing and decoupling, according to the researchers.

"Although comorbidity between alcohol consumption and mental health is complex, the landscape of the adolescent experience is changing in ways that may affect both consumption and mental health," observed Keyes. "The declining correlation between binge drinking and mental health is occurring during a time of unprecedented decreases in alcohol consumption among U.S. adolescents and increases in mental health problems. Therefore, the relationship between substance use and mental health may need to be reconceptualized for ongoing and future research."