Romantic breakups linked to lower hippocampal brain volume in adults with childhood trauma

A recent study published in the European Journal of Neuroscience sheds light on how childhood maltreatment may leave lasting impacts on brain structure, particularly in young adults who experience romantic relationship breakups. Researchers found that the combination of childhood maltreatment and the stress of a romantic breakup was associated with smaller hippocampal volumes, a brain region critical for memory and emotional regulation. This effect was not observed in individuals with childhood maltreatment who had not gone through a breakup, suggesting that later-life stressors might exacerbate the consequences of early adversity.

Childhood maltreatment has long been recognized as a significant risk factor for developing mental health disorders, such as depression and posttraumatic stress disorder, in adulthood. Previous research has linked childhood maltreatment to smaller hippocampal volumes, but inconsistencies remain, particularly in younger populations. Interestingly, hippocampal volume reductions are rarely observed during childhood or adolescence but emerge later in adulthood. This has led researchers to hypothesize that these structural changes might result from an interaction between early adversity and subsequent life stressors.

“I was inspired by two lines of research: Behavioral research showed that maltreated individuals develop strategies that help them survive an abusive childhood, but do not necessarily prepare them well for growing into adulthood,” said study author Henriette Acosta of the Philipps University of Marburg and University of Turku.

“Maltreated individuals are more likely to experience hardship at handling developmental tasks in adolescence and young adulthood, such as dealing with romantic relationships and their breakups. Childhood maltreatment is also a known risk factor for the development of psychopathology.”

“In neuroscience, maltreated individuals consistently showed reduced hippocampal volumes in adulthood, but not in childhood. Reduced hippocampal volumes develop after chronic stress exposure and are a brain structural feature of many psychiatric disorders. I was interested whether these two lines of research can be bridged.”

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The researchers recruited 196 healthy young adults with an average age of 24 years, half of whom were women. Participants were university students, and none had a history of major psychiatric disorders. They completed assessments to measure their exposure to childhood maltreatment and romantic relationship breakups. Childhood maltreatment was evaluated using the Childhood Trauma Screener, which captures experiences of emotional, physical, and sexual abuse, as well as neglect. Romantic breakups were assessed using a questionnaire that asked participants about their history of ending committed relationships.

Participants then underwent magnetic resonance imaging (MRI) scans to measure the volume of their hippocampi. The hippocampus, located in the brain’s temporal lobe, is known for its role in memory and emotional regulation and is often implicated in stress-related disorders. The researchers analyzed how childhood maltreatment and romantic breakups interacted to influence hippocampal volume, controlling for factors such as age, sex, and total brain size.

The researchers found that childhood maltreatment alone was not significantly associated with hippocampal volumes in young adults. However, the combination of childhood maltreatment and the experience of at least one romantic breakup was linked to smaller hippocampal volumes in both the left and right hemispheres of the brain. Specifically, individuals with a history of maltreatment and breakup exhibited smaller hippocampal volumes compared to those who had experienced childhood maltreatment but no breakup.

Interestingly, the results also suggested a potential dose-response relationship: greater levels of childhood trauma were associated with smaller hippocampal volumes in individuals who had experienced a breakup. In contrast, among participants who had not experienced a breakup, greater childhood trauma was weakly associated with larger hippocampal volumes, a finding the researchers speculated might reflect resilience in certain individuals.

These effects were slightly more pronounced in the left hippocampus than in the right and appeared to be stronger for experiences of neglect (deprivation) than abuse (threat). Additionally, participants who were living with a romantic partner at the time of the study showed weaker associations between maltreatment, breakups, and hippocampal volume, suggesting that stable relationships may act as a buffer against the negative effects of stress.

“Our brain imaging findings matched with the behavioral research observations that maltreated individuals (compared to non-maltreated individuals) experience more distress in coping with developmental tasks,” Acosta told PsyPost. “After the experience of a relationship breakup, hippocampal volumes were reduced in maltreated individuals, but not in non-maltreated individuals: The more severe the childhood maltreatment, the smaller the hippocampal volumes. Smaller hippocampal volumes are a feature of adult psychopathology. Importantly, childhood maltreatment per se was not associated with smaller hippocampal volumes in young adults.”

“Our study therefore supports the notion that childhood maltreatment increases the individual’s sensitivity to stressors and the increased stress sensitivity renders the maltreated individual more susceptible to the development of psychopathology. Our results also provided some evidence that the experience of a stable committed romantic relationship in young adulthood partly acts as a resilience factor in the face of childhood maltreatment and past relationship breakups.”

But the study, like al research, includes some caveats. Notably, the study relied on retrospective self-reports of childhood maltreatment and romantic breakups, which may be subject to memory biases or underreporting. More detailed and longitudinal assessments could provide a clearer picture of how these experiences interact over time.

“The study was cross-sectional, and no causal relationships can be inferred,” Acosta noted. “Childhood trauma and relationship breakup experiences were assessed retrospectively which can bias the findings.”

The study, “The association between childhood adversity and hippocampal volumes is moderated by romantic relationship experiences,” was authored by H. Acosta, A. Jansen, and T. Kircher