Preschool may be an effective tool in the fight against addiction, a new study suggests. The study of more than 1,500 children found those who had attended preschool were 28 percent less likely to develop substance abuse problems.

Time reports that the study followed the children from age 3-4 to age 28. The children in the study lived in low-income neighborhoods in Chicago and most were African American. Those who attended preschool were less likely to develop alcohol and drug problems or to end up in jail or prison, the researchers found. They were 24 percent more likely to attend a four-year college, and their incomes were higher, the researchers wrote in Science. The families of the children enrolled in preschool were actively involved in the program.

Preschool had the biggest positive effect for boys and for children with the least educated parents.