Evidence does suggest that teens with ADHD are more likely than their peers to abuse alcohol or other drugs. For example, one twin study found that teens with ADHD started drinking alcohol and using marijuana significantly earlier than their peers, on average, and were also more likely to escalate to heavy use. The link between ADHD and substance abuse is theorized to be due to impulsivity, poor judgment, genetic vulnerability, and/or because substances may serve as a coping mechanism for problems in school or difficulties getting along with peers. Just because a teen has ADHD, however, does not mean he is destined to misuse substances. Open communication with parents, healthy alternative activities, and appropriate ADHD treatment can all reduce the risk of problematic drug and alcohol use during adolescence and young adulthood.