Study co-author Bill McCarthy of the University of California, Davis, and colleagues analyzed data from 1995 and 1996 from nearly 15,000 seventh- to ninth-grade students in the federally funded National Longitudinal Study of Adolescent Health.
McCarthy and Teresa Casey, a postdoctoral researcher, found about 29 percent of the youth surveyed reported having committed at least one criminal offense, while 18 percent said they had used at least one illegal drug. The researchers then correlated this data with self-assessments of emotional well-being.
The study found happier adolescents were less likely to report involvement in crime or drug use, but teens with minor, or non-clinical, depression had higher odds of crime or drug use.
However, adolescents who experienced a decrease in their level of happiness or an increase in depression over a one-year period had higher odds of being involved in crime and of using drugs, the study says.
The findings were presented at the American Sociological Association annual meeting in Las Vegas.