Childhood maltreatment tied to altered neural processing of positive, negative memories
Children who have experienced maltreatment may have altered autobiographical memory (ABM) functioning, which entails reduced activation in areas encoding positive memories, leading to them according heightened salience to negative memories, a study has shown.
Such pattern of memory processing may confer latent vulnerability to developing depression and post-traumatic stress disorder (PTSD), according to a team of UK-based investigators.
In the study, a total of 34 children (mean age 12.53 years; 50 percent female) with documented maltreatment and 33 matched controls without maltreatment history underwent an ABM test aimed at generating specific memories in response to emotionally valenced cue words during functional magnetic resonance imaging (fMRI). There were three memory conditions: positive ABM recall, negative ABM recall and object recall.
The resulting AMT performance showed that the maltreatment group generated more overgeneral memories (OGMs) across the memory conditions. Furthermore, fMRI data revealed a significant group-valence interaction for emotion at the whole brain level. [Br J Psychiatry 2017;doi:10.1192/bjp.bp.117.201798]
Compared with controls, children with documented maltreatment experience had diminished hippocampal and heightened middle temporal and parahippocampal activation during positive ABM recall, and increased amygdala activation and amygdala connectivity with the salience network during negative ABM recall.
“The present [findings] demonstrate that children who have experienced maltreatment are characterized by a pattern of OGM and altered neural processing of positive and negative memories,” the investigators said, adding that such pattern of processing may instantiate latent vulnerability to a psychiatric disorder in two ways.
“First, greater OGM may reduce the ability of children who have been maltreated to draw on past experiences in order to effectively negotiate future stressors… [and] OGM [is] associated with reduced problem solving in depression and PTSD,” they said.
“Second, decreased specificity and salience of positive, relative to negative, memories … may increase the likelihood of a negative inferential style, negative self-schemata and a ruminative response style, all cognitive vulnerabilities associated with maltreatment and central to cognitive theories of depression and psychiatric population,” they continued.
The investigators highlighted the prospect that ABM functioning represents a potential target for preventative intervention against psychiatric disorders in the at-risk population of children who have experienced maltreatment.
Due to the cross-sectional nature of the study, however, it was not possible to examine the developmental trajectories of altered ABM processing. Longitudinal studies are thus warranted to further test the hypothesis that ABM is a candidate latent vulnerability mechanism for psychiatric disorder following childhood maltreatment, the investigators said.