The age of exposure to childhood maltreatment may influence amygdala response to threatening emotional stimuli, according to study data published in JAMA Psychiatry. Patients with prepubertal maltreatment exposure tended to demonstrate reduced amygdala response, whereas patients with postpubertal exposure had augmented response.

Investigators conducted a retrospective cohort study with patients from the Boston area. Participants were administered the Maltreatment and Abuse Chronology of Exposure scale to capture type and age of exposure to childhood maltreatment. Patients then underwent functional magnetic resonance imaging while completing an emotional face-matching task. The task comprised a set of angry and fearful faces along with neutral faces and shapes; bilateral amygdala response to each stimulus was captured with functional magnetic resonance imaging. Emotional face ellipse area was calculated to assess the homogeneity of responses to each stimulus type; patients with smaller ellipse areas had more homogenous responses to similar stimuli. Predictive analytics were used to identify exposure periods associated with certain amygdala response patterns.

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Among 202 enrolled participants (mean [standard deviation] age, 23.2 [1.7] years; 58.4% women), 150 (74.3%) reported exposure to 1 or more maltreatment types. Risk factors associated with bilateral amygdala response to emotional faces vs shapes were peer emotional abuse at 13 (P =.03) and 15 (P =.006) years of age, parental physical abuse at 3 (P =.046) to 4 (P =.02) years of age, and peer physical abuse at 6 years of age (P =.01). Exposure to peer emotional abuse at 13 and 15 years of age was associated with augmented response to emotional faces vs shapes, whereas earlier exposure was associated with blunted response (both P <.001). Larger emotional ellipse areas, denoting less homogenous amygdala response, were observed among patients who reported physical abuse at 4 years of age compared with patients who did not (P <.001). However, patients reporting nonverbal emotional abuse at years of age had smaller emotional ellipse areas compared with their counterparts without this experience (P <.001). As such, prepubertal vs postpubertal maltreatment was associated with opposite response patterns for clustering for stimuli of the same type. Similarly, amygdala response patterns to stimuli of different types also correlated with exposure period. Specifically, amygdala response to emotional vs neutral faces was greater among patients exposed to peer emotional abuse at 6 years of age than among those exposed to the same treatment at 13 years of age (P <.001).

These data suggest that attenuated vs enhanced amygdala response patterns may correlate with the developmental period during which maltreatment was experienced. Patients with prepubertal exposure tended to have reduced amygdala response, whereas postpubertal exposure was associated with stronger response. Investigators hypothesized that adolescents may be able to reduce their exposure to maltreatment through fight-or-flight reactions, in which case a strong amygdala response would be advantageous.

The study was limited by the self-reported nature of the maltreatment and the small sample size.

“Understanding the role of adversity in different sensitive exposure periods and the potential adaptive significance of…amygdala response may help explain why maltreatment may be a risk factor for many different disorders and foster creation of targeted interventions to preempt the emergence of psychopathology in at-risk youths,” the investigators concluded.

Reference

Zhu J, Lowen SB, Anderson CM, Ohashi K, Khan A, Teicher MH. Association of prepubertal and postpubertal exposure to childhood maltreatment with adult amygdala function [published online June 26, 2019]. JAMA Psychiatry. doi:10.1001/jamapsychiatry.2019.0931