As more states legalize the use of marijuana, the number of teens with cannabis-related problems is declining, new research suggests. Published in the Journal of the American Academy of Child & Adolescent Psychiatry, the study revealed a 24% decline in marijuana-related problems-such as becoming dependent on the drug or having trouble in school and in relationships-among teenagers. The researchers additionally found an association between drops in problems related to cannabis and reductions in behavioral issues, such as fighting, property crimes and selling drugs. The report also showed that marijuana use rates in young people have been dropping over the years. When asked whether they had used marijuana in the previous 12 months, study participants reported fewer instances of pot use in 2013 than their peers had reported in 2002, a 10% decline overall. Additional research on how the decrease in rates of conduct problems relates to other behaviors is needed. "For example, adolescent crime rates have been declining for about 20 years. Teenage pregnancy rates are at an all time low. Binge drinking among high school students is dropping. (Though you wouldn't know any of this from news coverage)," [study author Richard A. Grucza] said. "I think it is likely that all of these changes are connected to each other, and to the drop in marijuana use disorder. It's really important to figure out why this is happening so that we can extend these trends into the future."