CHICAGO (AP) — A study has found high rates of drug and alcohol abuse and dependency among some who went through Cook County's juvenile detention center.

The Northwestern Medicine study found more than 90 percent of males and nearly 80 percent of females in the study were diagnosed with a "substance abuse disorder" at some point in their lives. The study was published Thursday.

The Chicago Tribune (http://trib.in/1Rq95Q0 ) reports the study looked at 1,829 youths detained between 1995 and 1998 at the county's Juvenile Temporary Detention Center in Chicago, and followed up with them at least nine times in 12 years.

Racial disparities were found in the study. African-Americans were less likely to have cocaine-use disorders than non-Hispanic white youths, who were 30 times more likely to abuse cocaine. Hispanic youths were 20 times more likely to use cocaine than African-Americans.