Early life distress, brain changes, and internalizing problems
Dec 3, 2012
As a preface to the rest of this post, let me explain that by "internalizing problems" I mean such "internalizing symptoms" as depression, worry, fear, self-injury, and social withdrawal. This page discusses how internalizing symptoms present in Borderline Personality Disorder [LINK] though they are also common with a variety of other disorders. Behavioral and psychological problems are often described in terms of their degrees of internalizing versus externalizing presentation. The major distinction between these two presentations is related to whether the symptoms or behaviors are focused inward (i.e., toward to the self) or outward (i.e., toward others).
Researchers at the University of Wisconsin-Madison have recently published a paper (Burghy et al [LINK] examining the relationship between early life stress (ELS) and problems in adolescents exhibiting internalizing symptoms. ELS can refer to a number of experiences but in this study ELS referred to largely maternal experiences of environmental stressors (as a methodological note, see Schrieber et al 2006 [LINK]) It is known that ELS and function of the hypothalamic-pituitary-adrenal axis predict later psychopathology. Animal studies and cross-sectional human studies suggest that this process might operate through amygdala–ventromedial prefrontal cortex (vmPFC) circuitry implicated in the regulation of emotion. The Burghy et al study prospectively investigated the roles of ELS and childhood basal cortisol amounts in the development of adolescent resting-state functional connectivity (rs-FC), assessed by functional connectivity magnetic resonance imaging (fcMRI), in the amygdala-PFC circuit. The study found, but in females only, that greater ELS predicted increased childhood cortisol levels, which predicted decreased amygdala-vmPFC rs-FC 14 years later. For females, adolescent amygdala-vmPFC functional connectivity was inversely correlated with concurrent anxiety symptoms but positively associated with depressive symptoms, suggesting differing pathways from childhood cortisol levels function through adolescent amygdala-vmPFC functional connectivity to anxiety and depression. These data highlight that, for females, the effects of ELS and early HPA-axis function may be detected much later in the intrinsic processing of emotion-related brain circuits.
I am at a loss, especially given my own experience of early stress, and exposure to maternal distress, as to why similar results were not found in males, and Burghy et al also don't offer any explanation for this difference.