Bullying in late adolescence is uniquely related to abnormal brain microstructure among individuals with current diagnoses of depression, possibly due to an overactive fear response, according to a recent study. Researchers examined fractional anisotropy (FA) in multiple white matter tracts in 186 adults (93 males, 93 females) with a current diagnosis of major depressive disorder (MDD), including 88 who reported a history of bullying before age 18 (43 males; 45 females). All patients were antidepressant medication-free at the time of testing. They found:

• After adjusting for demographics and other early life stress (ELS) subtypes, participants with a history of bullying exhibited increased FA in the right medial lemniscus and left posterior corona radiata compared to participants with depression but no self-reported history of bullying.
• Both groups endorsed similar levels of depression.
• Group differences were most pronounced among individuals who endorsed bullying in late adolescence (aged 14-17 years).