Abnormalities in amygdala response to threatening faces have been observed in a variety of mental illnesses, such as posttraumatic stress disorder (PTSD), anxiety, and depression. Abnormal patterns of hyperactive and hypoactive amygdala responses have been associated with inappropriate social behaviors. Childhood maltreatment is often linked to these abnormal amygdala activation patterns. The majority of the evidence for this relationship comes from structural and functional magnetic resonance imaging studies that have been able to retrospectively characterize alterations observed in maltreated individuals. A prominent finding has been increased reactivity of the amygdala to threatening stimuli. This overactive amygdala threat detection process has been described by researchers as a potential mechanism of a maltreatment-induced maladaptive developmental trajectory that results in subsequent psychiatric difficulties. However, not all individuals who experience childhood maltreatment develop mental disorders, and individuals who experience similar maltreatment may manifest psychopathic symptoms through different biological mechanisms. Some researchers suggest that maltreatment may induce distinct neurobiological phenotypes through a cascade of experience-dependent plasticity inductions that modify neurocircuitry during development as an evolutionary adaptive function. In a recent cohort study, 202 individuals with self-reported early childhood maltreatment underwent functional magnetic resonance imaging. The purpose of the study was to investigate the association between exposure to childhood maltreatment at different ages and adult amygdala response to threatening faces. Early childhood maltreatment was associated with blunted amygdala response (ß = -0.17, P < 0.001), whereas early teen exposure to maltreatment was associated with augmented amygdala response (ß = 0.16, P < 0.001). The findings suggest that prepubertal versus postpubertal developmental differences exist in the association between maltreatment and subsequent amygdala response to threatening stimuli. Further understanding of exposure to maltreatment during critical periods in development may result in more effective and appropriate interventions for at-risk youths.
References:
Fonzo, GA. JAMA Psychiatry 2019;76(8):781-782. Abstract
Jianjun et al. JAMA Psychiatry 2019;76(8):843-853. Abstract
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