Amygdala, Hippocampus, and Ventral Medial Prefrontal Cortex Volumes Differ in Maltreated Youth with and without Chronic Posttraumatic Stress Disorder

Abstract

Posttraumatic stress disorder (PTSD) is considered a disorder of recovery where individuals fail to learn and retain extinction of the traumatic fear response. In maltreated youth, PTSD is common, chronic, and associated with comorbidity. Studies of extinction-related structural volumes (amygdala, hippocampus, anterior cingulate cortex (ACC), and ventral medial prefrontal cortex (vmPFC)) and this stress diathesis, in maltreated youth were not previously investigated. In this cross-sectional study, neuroanatomical volumes associated with extinction in maltreated youth with PTSD (N=31), without PTSD (N=32), and in non-maltreated healthy volunteers (n=57) were examined using magnetic resonance imaging. Groups were sociodemographically similar. Participants underwent extensive assessments for strict inclusion/exclusion criteria and DSM-IV disorders. Maltreated youth with PTSD demonstrated decreased right vmPFC volumes compared with both maltreated youth without PTSD and non-maltreated controls. Maltreated youth without PTSD demonstrated larger left amygdala and right hippocampal volumes compared with maltreated youth with PTSD and non-maltreated control youth. PTSD symptoms inversely correlated with right and left hippocampal and left amygdala volumes. Confirmatory masked voxel base morphometry analyses demonstrated greater medial orbitofrontal cortex gray matter intensity in controls than maltreated youth with PTSD. Volumetric results were not influenced by psychopathology or maltreatment variables. We identified volumetric differences in extinction-related structures between maltreated youth with PTSD from those without PTSD. Alterations of the vmPFC may be one mechanism that mediates the pathway from PTSD to comorbidity. Further longitudinal work is needed to determine neurobiological factors related to chronic and persistent PTSD, and to PTSD resilience despite maltreatment.

Structural covariance network centrality in maltreated youth with posttraumatic stress disorder

“…Previous research has also shown structural and functional disruptions to OFC and ACC in survivors of childhood maltreatment (Kelly et al, 2013; Lim et al, 2014; Teicher et al, 2014) and those with PTSD (Morey et al, 2016; Mueller et al, 2015; Spielberg et al, 2015). We hypothesized that maltreatment would be broadly associated with altered centrality in OFC and in the ACC, particularly children with PTSD as disruptions in these neural networks may increase their vulnerability to the disorder.…”

“…About 20–30% of maltreated youth meet criteria for chronic posttraumatic stress disorder (PTSD) (McLeer et al, 1998; McLeer and Ruggiero, 1999), which is accompanied by heightened threat response and difficulty inhibiting fear response to traumatic reminders. We recently reported that maltreated youth with chronic PTSD, when compared to maltreated youth without PTSD, have smaller volumes in brain areas associated with fear extinction, emotion and memory processing, including left amygdala, right hippocampus and right ventromedial prefrontal cortex (Morey et al, 2016). …”

The complex neurobiology of resilient functioning after child maltreatment

“…Smaller hippocampal volume (partially) mediated the effect of CM on adolescent depression during a 5-year follow-up (Rao et al, 2010) and behavioural problems in children (Hanson, Nacewicz, et al, 2015). Larger hippocampal volumes, on the other hand, have been related to CM in healthy samples, suggesting a possible marker of resilient functioning (Mehta et al, 2009;Morey et al, 2016;Thomaes et al, 2010;Nim Tottenham et al, 2010;. Indeed, CM was not related with hippocampal volume reductions in resilient adults (i.e.…”

“…Resilient functioning (i.e. the absence of mental health disorders) in those with a history of CM has been related with larger volume of (midline) PFC regions (Morey, Haswell, Hooper, & De Bellis, 2016;Sarah Whittle et al, 2009). Importantly, larger PFC volumes are also implicated in resilient functioning across a range of domains after CM.…”

“…In healthy adolescents, CM is linked to both reductions (Edmiston et al, 2011;Mehta et al, 2009) and increases in amygdala volume (Holz et al, 2016;Morey et al, 2016;Sarah Whittle et al, 2009). Along the same lines, a recent meta-analyses suggest no amygdala alterations in healthy individuals with a history of CM (Calem, Bromis, McGuire, Morgan, & Kempton, 2017;Paquola et al, 2016), and amygdala volume did not mediate the link between CM and behavioural problems (Hanson, Nacewicz, et al, 2015).…”