A new study has found that early drug and alcohol use is associated with lower levels of educational achievement.
A study of 6,242 twins shows a link between fewer years of schooling and the onset of drinking before age 14, report researchers from the Washington University School of Medicine in St. Louis and the Palo Alto Veterans Affairs Health Care System.
The study looked at male twins who served in the military during the Vietnam era, discovering that those who began drinking or using drugs as young teens or who became dependent on alcohol, nicotine or marijuana were less likely to finish college than those who didn’t use alcohol or drugs until later in life and never became dependent.
“We can’t say that substance dependence or early substance use causes lower educational achievement, but we do see a strong association,” said lead author Julia D. Grant, Ph.D., research assistant professor of psychiatry at Washington University School of Medicine. “Even after we statistically controlled for the genes and the environmental factors that twins share, we found a relationship between substance use and educational achievement.”
She noted that studying identical and fraternal twins is useful for examining things like substance use and education “because we can assess the extent to which a given behavior is influenced by genetic factors and by factors related to family and environment. Since identical twins share all of their genes and fraternal share about half, we can set up statistical comparisons to tease many of those factors apart.”
In the analysis, the researchers found that when the men began to drink or use drugs early in their teen years or if they became a drug addict or alcoholic, they were less likely to complete 16 years of education.
The men were surveyed when most were in their late 30s or early 40s, a point in their lives when it was less likely they would further their education, Grant added.
Veterans, she says, were a particularly good group to follow because it is rare for anyone to serve in the military without finishing high school or earning a GED. In addition, because of the G.I. Bill, veterans are less likely to have financial constraints that would prevent them from attending college.
The findings provide more evidence that early drug and alcohol use is associated with a large number of problems later in life, according to Grant.
“Drugs and alcohol affect many lifetime milestones, such as marriage, parenthood and employment, which are closely linked to education,” she said. “These events in later life all are influenced by early substance use, and this study provides further evidence that as a society, we need to continue our public-health efforts to reduce underage drinking, smoking and use of drugs.”