FRIDAY, Oct. 24, 2008 (HealthDay News) -- Children who start drinking or using drugs before age 15 are more likely to have poor health as adults, according to a University of California, Irvine, study that enrolled more than 1,000 3-year-old children and followed them for 30 years.
By the time the participants were 32 years old, those who had used alcohol or drugs before age 15 were two to three times more likely to have developed substance dependence, contracted sexually transmitted diseases (STDs), dropped out of school, or acquired criminal records.
UCI psychologist Candice Odgers and her colleagues also found that females who used drugs and alcohol before age 15 had higher pregnancy rates than females who didn't use illicit substances before age 15.
Alcohol was the most common illicit substance use by teens, but use of a variety of substances caused a greater risk of poor health in adulthood. The researchers also found that among adults who had behavioral problems as children, early exposure to alcohol and drugs greatly increased their risk for substance abuse, school failure and criminal convictions.
Interestingly, the study also found that 50 percent of the teens exposed to drugs and alcohol before age 15 had no prior history of behavioral problems.
"Findings from this study are consistent with the message that early substance use leads to significant problems in adolescents' future lives (that drugs are bad for kids) versus the alternative message that young adolescents with [a] history of problems are just more likely to use drugs early and experience poor outcomes (that bad kids do drugs)," Odgers said in an Association for Psychological Science news release.
"Even adolescents with no prior history of behavioral problems or family history of substance abuse problems were at risk for poor health outcomes if they used substances prior to age 15. Universal interventions are required to ensure that all children -- not only those entering early adolescence on an at-risk trajectory -- receive an adequate dose of prevention," she added.
The study was published in the October issue of the journal Psychological Science.
The Nemours Foundation has more about teens and alcohol.