Childhood maltreatment mediates the effect of spontaneous brain activity on depressive temperament

Affective temperaments serve as biological substrates for mood disorders, with depressive temperament (DT) representing a subclinical vulnerability marker for major depressive disorder. Childhood maltreatment (CM) is a well-established environmental risk factor, yet the neurobiological mechanisms linking CM to DT remain incompletely understood.

We recruited 97 psychiatrically healthy adults (59 females; age 18-41 years) with varying degrees of CM. Participants completed the Childhood Trauma Questionnaire-Short Form (CTQ-SF) and underwent resting-state functional MRI. Regional homogeneity (ReHo) was used to assess spontaneous brain activity, combined with whole-brain correlation, support vector regression, and mediation analyses to examine associations among brain activity, CM, and DT.

CTQ scores were positively correlated with ReHo in the right hippocampus and left insula, and negatively correlated with ReHo in the right lingual gyrus. CM severity fully mediated the association between ReHo in the hippocampus/insula and DT, with CM explaining 22.5-23.6% of the variance, consistent with a unidirectional pathway (ReHo → CM → DT).

Cross-sectional design and retrospective CM assessment limit causal inference and generalizability to clinical populations.

Our findings demonstrate a unidirectional pathway wherein spontaneous brain activity in the hippocampus and insula is associated with DT through subjective CM severity. This positions CM as a critical psychological mechanism linking neural susceptibility to affective vulnerability, highlighting the importance of addressing maltreatment-related appraisal processes in early intervention strategies.