Teen troubles linked to brain differences

Young teens who react to their parents’ criticisms with extreme moodiness or anger may have different brain structures than calmer adolescents, according to new research.

Sarah Whittle and colleagues asked 137 young teens and their parents to participate in 20-minute “problem solving” sessions in order to assess the teens’ reactions to conflict. During these sessions, the researchers asked the children and their parents to discuss touchy topics that elicited negative feelings. The researchers videotaped the sessions and evaluated the children’s moods and levels of aggressive behavior (including behavior that was contemptuous, angry, belligerent, disapproving, threatening, or argumentative). Afterward, the teens underwent MRI (magnetic resonance imaging) scans.

The researchers found that children who exhibited the most prolonged aggressive responses to conflict during the sessions had larger amygdala volumes than the easier-going teens. The amygdala is associated with anger and response to threats, and increased amygdala activity is reported in aggressive adults.

In addition, the researchers detected differences in the prefrontal regions of the brain in moody or aggressive boys. Boys with reduced leftward asymmetry of the anterior cingulate cortex (ACC) showed aggressive behavior for longer periods after a conflict than other boys did, and boys with decreased leftward asymmetry of the orbital frontal cortex (OFC) were more likely to reciprocate a parent’s negative mood. These regions appear to play a role in regulating mood, possibly by inhibiting the influence of the amygdala.

Brain changes in adolescence, the researchers note, “are believed to underlie a shift from behavior that is driven by affective impulses to more regulated behavior that is guided by consideration of future personal and social consequences.” The brain differences seen in the moody or aggressive boys, they say, may represent a delay in this biological maturation.