A review of adversity, the amygdala and the hippocampus: a consideration of developmental timing

Abstract

A review of the human developmental neuroimaging literature that investigates outcomes following exposure to psychosocial adversity is presented with a focus on two subcortical structures – the hippocampus and the amygdala. Throughout this review, we discuss how a consideration of developmental timing of adverse experiences and age at measurement might provide insight into the seemingly discrepant findings across studies. We use findings from animal studies to suggest some mechanisms through which timing of experiences may result in differences across time and studies. The literature suggests that early life may be a time of heightened susceptibility to environmental stressors, but that expression of these effects will vary by age at measurement.

Dissociable relations between amygdala subregional networks and psychopathy trait dimensions in conduct‐disordered juvenile offenders

“…As interactions between psychopathology and age have been shown to affect amygdaloid function and structure [Tottenham and Sheridan, 2009; Weems et al, 2013, 2015] post‐hoc exploratory analyses specifically tested for an age x psychopathic traits interaction effect on trait‐specific amygdalar iFC patterns mentioned above (i.e., patterns that we elaborate on in the Discussion). As such, employing FSL's FEATquery tool on individual participant's connectivity maps, subject‐level connectivity measures (i.e., mean Z‐ values) were first extracted from clusters of brain regions that exhibited trait‐specific iFC with amygdala subregions in our group‐level analysis (clusters are depicted in Fig.…”

“…For instance, although we tested for an age x psychopathic traits interaction effect on trait‐specific iFC patterns, the limited age range and modest size of our sample may have precluded a thorough examination of any anticipated age‐related effects. Studies with relatively larger samples and wider age range have indeed documented age‐related variations in amygdala subregional connections [Qin et al, 2012], as well as age x psychopathology interaction effects on amygdaloid function and structure [Tottenham and Sheridan, 2009; Weems et al, 2013, 2015]. Similar to the majority of studies on conduct disorder and psychopathic traits in juvenile populations, some of our conduct‐disordered participants had comorbid ADHD, while others reported high levels of substance use.…”

“…Considering the developmental variation in amygdala subregional connectivity [Qin et al, 2012], exploratory analysis additionally probed whether these trait‐specific iFC patterns might be impacted by age. This could be of importance, as interactions between psychopathology and age/maturation have in some cases been shown to impact amygdaloid function and structure [Tottenham and Sheridan, 2009; Weems et al, 2013, 2015]. …”

Interpersonal early‐life trauma alters amygdala connectivity and sustained attention performance

“…While it is possible that the nature of the traumatic experience may have been different depending on the sex of the participant, our analyses do not show significant outliers in PTSD severity or performance that would indicate the presence of two behavioral phenotypes. Most studies of childhood trauma have either examined one specific gender or have reported groups that were uneven, preventing them from conducting gender‐related analyses of the impact of ELT on amygdala structure and function (Tottenham & Sheridan, 2010). However, current research suggests that potential gender differences do exist in sustained attention ability and the strategy used by participants in completing sustained attention tasks.…”

“…Converging evidence points to a lasting impact of trauma experienced during sensitive periods in childhood (Anda et al., 2006), with developmental trajectories occurring pre/periadolescence irremediably altered by exposure to significant stress (Bergman, Larsen, & Mueller, 1986; Mullen, Martin, Anderson, Romans, & Herbison, 1996; Perry, Pollard, Blakley, Baker, & Vigilante, 1995; Tottenham & Sheridan, 2010). Stressors of an interpersonal nature, like physical/sexual abuse or family violence, occur in 9.5% (Sachs‐Ericsson, Blazer, Plant, & Arnow, 2005) to 32% of the general population (Cougle, Timpano, Sachs‐Ericsson, Keough, & Riccardi, 2010) and are thought to cause enduring emotional or cognitive impairments due in great part to the human agency behind the threat (De Bellis & Zisk, 2014; Perry et al., 1995).…”