Students who earn good grades in school are less apt to use alcohol, tobacco or other drugs, according to researchers from the University of Michigan's Institute for Social Research.

Science Daily reported Oct. 6 that researchers studied a group of 3,000 students from about age 14 to age 22 and found that those who set an early pattern of educational achievement were less likely to smoke, drink, or take drugs.

"Grade point averages at the end eighth grade are strongly linked to smoking at that time, and strongly predictive of later smoking," said researcher Jerald G. Bachman. "For example, practically none of the students with an A average were daily smokers at age 14, versus more than a quarter of the students with grades of D or lower. By age 22, half of those who had been D students had become daily smokers, compared with about a quarter of those who had been A students in eighth grade."

During high school, factors like poor grades, suspension, or expulsion from school were accurate predictors of illicit-drug use. Bachman and colleagues also found that half of high-school dropouts had become daily smokers by age 22, compared to about one-fifth of students with three or more years of college.

However, college students were more likely to drink than their less-educated peers. "At ages 14 and 16, drinking is most likely among students not doing well in school. But by age 20 the college students surpass their less-educated age-mates in their use of alcohol -- especially in occasions of heavy drinking," the study noted. On the other hand, college-educated adults are somewhat less likely to drink heavily by the time their reach age 30 than the average adult.

The findings were based on data from the Monitoring the Future survey. This and other reports are published in a new book by Bachman and colleagues called The Education-Drug Use Connection: How Successes and Failures in School Relate to Adolescent Smoking, Drinking, Drug Use, and Delinquency.