Study explores the effects of alcohol and cannabis on aggression-linked brain circuitry in teens Alcohol and cannabis use during adolescence is a well-known risk factor for alcohol use disorder (AUD) and cannabis use disorder (CUD) during adulthood. Whether early drug use plays a causative role in predisposing teens to AUD and CUD is unknown, but researchers are investigating the possibility that it may have an impact on neural development. Evidence suggests that an increased propensity for aggression may underlie the risk. Now, a study in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, published by Elsevier, shows that teens with more severe AUD or CUD displayed stronger retaliatory behaviors, but only those with AUD - and not CUD - had altered brain activity in aggression circuits.