Amygdala hyperactivation in childhood maltreatment: An ALE-based meta-analysis on emotion-related processing

Childhood maltreatment (CM), encompassing various forms of abuse and neglect, is associated with adverse developmental outcomes and heightened risk for psychiatric conditions. Functional magnetic resonance imaging (fMRI) studies point to altered neural responses during tasks involving emotion-related processing in maltreated individuals, yet inconsistent findings have limited the field's ability to draw clear conclusions about the loci of altered brain function. This meta-analysis aimed to synthesize existing task-based fMRI data on emotional processing in individuals with a history of childhood maltreatment, with particular emphasis on identifying consistent patterns of hyperactivation compared to non-maltreated controls. A systematic search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines across Web of Science, Scopus, PubMed, and PsycInfo identified 674 studies, of which 30 met the inclusion criteria. Using the Activation Likelihood Estimation (ALE) method, the meta-analysis incorporated 368 brain coordinates (foci) and 93 contrasts from experiments involving 2474 participants (1169 in the maltreatment group and 1305 in the control group). The ALE analysis identified a robust cluster of hyperactivation in the right amygdala in maltreated individuals during emotional processing tasks. Peak activation was observed at [20, -4, -16], suggesting heightened threat detection and emotional reactivity in those with a history of childhood maltreatment. No significant clusters emerged for increased activation in the control group. These findings underscore the amygdala's central role as a neural substrate affected by childhood maltreatment, contributing to heightened emotional reactivity and dysregulated emotion-related processing in affected individuals.