A recent study published in * Molecular Psychiatry* provides evidence that experiencing abuse during different stages of childhood and adolescence alters how the brain processes emotions in adulthood. The research suggests that the specific age when trauma occurs tends to dictate which emotion-processing areas of the brain become hyperactive later in life. These findings offer insights into why childhood abuse increases the risk for mental health disorders like depression and post-traumatic stress disorder (PTSD).
The brain relies on a highly interconnected network of structures to interpret and respond to the social world. Two major regions involved in this neural network are the amygdala and the hippocampus. The amygdala acts as a rapid detection center for emotional information, particularly regarding potential environmental threats. The hippocampus works alongside the amygdala to provide context, linking emotional responses to specific memories and past situations.
Together, these brain areas help people process emotions on two entirely different levels of awareness. Conscious emotion processing happens when a person has enough time to deliberately recognize and think about an emotional trigger, engaging the brain’s higher thinking centers. Non-conscious processing occurs in a fraction of a second, triggering automatic bodily responses before a person even realizes what they are looking at.
Mayuresh Korgaonkar, an associate professor and research director at the Brain Dynamics Centre at Westmead Institute for Medical Research at the University of Sydney, wanted to investigate these developmental impacts. He noted that the field needed more clarity regarding these long-term emotional changes.
“We’ve known for a long time that abuse in childhood raises the risk of mental health problems in adulthood, but far less is understood about how this adverse experience shapes something as fundamental as how we process and react to emotions,” Korgaonkar said. “We also don’t know when during development the brain is most vulnerable.”
Despite knowing that early trauma affects brain development, the scientific community lacks consensus on whether specific developmental windows are more sensitive to these disruptions. Past studies often grouped all childhood and adolescent years together or used varying definitions of childhood maltreatment. The authors designed this study to evaluate whether abuse experienced before age 13 impacts the brain differently than abuse experienced during adolescence.
“While there has been a lot of interest in this topic, existing studies have been inconsistent, partly because they lumped different ages and types of adversity together,” Korgaonkar explained. “We wanted to look at whether abuse before versus after age 13, a key developmental milestone, leaves different fingerprints on how the adult brain processes emotion.”
He added that the research team chose this specific focus for practical clinical reasons. “We focused on emotion processing because difficulty in this area is one of the most commonly reported problems across several mental health conditions,” Korgaonkar said.
Add PsyPost to your preferred sources The researchers also looked at a broad sample of people with different mental health diagnoses. By including individuals with depression, anxiety, and PTSD, alongside healthy adults, the scientists wanted to isolate the specific effects of abuse from the effects of the mental health conditions themselves.
“Another important question is whether these effects are tied to a single disorder or shared across diagnoses,” Korgaonkar said. “And we tried to unpack this by bringing together a cohort of multiple psychiatric conditions in addition to healthy volunteers.”
To test these ideas, the researchers analyzed data from 635 adult participants between the ages of 18 and 65. The sample included 399 adults with no history of abuse and 236 adults who reported experiencing emotional, physical, or sexual abuse before the age of 18. The participants were classified into diagnostic groups based on structured psychiatric interviews.
Participants underwent functional magnetic resonance imaging, commonly known as fMRI. This is a specialized type of brain scan that measures changes in blood flow to detect which brain areas are active in real time. While inside the scanner, the participants completed a visual task that required them to view images of human faces.
The images displayed six different facial expressions, which included fear, anger, sadness, disgust, happiness, and a neutral expression. The faces were presented in two distinct ways to test different emotional pathways in the brain.
For the conscious processing task, the faces appeared on a screen for 500 milliseconds, which is long enough for a person to explicitly recognize the emotion. For the non-conscious processing task, the faces flashed on the screen for just 10 milliseconds, which is too fast for the conscious mind to register. The researchers then compared brain activity between those who experienced abuse and those who did not. They paid special attention to the age when the trauma first occurred, separating the abused group into those who experienced trauma before age 13 and those who experienced it between the ages of 13 and 18. The data provides evidence that the timing of the abuse distinctly alters different neural pathways.
Korgaonkar pointed out that this specific division yielded unexpected results. “The most surprising bit was a ‘double dissociation’ that split by age,” he said.
“People abused in their teens showed heightened amygdala activity, i.e. the brain’s rapid threat detector, but only during conscious emotion processing when faces were shown long enough to be consciously seen,” Korgaonkar told PsyPost. “On the other hand, people abused before age of 13 showed heightened hippocampal activity, a region which stores our emotional memories, and this was during rapid, below awareness processing of emotions, a more automatic reaction.”
This divergence suggests that early childhood trauma might become hardwired into the brain as an automatic, non-conscious response to negative stimuli. Meanwhile, adolescent trauma might specifically affect the brain pathways involved in deliberately appraising and thinking about emotional information.
“So the same kind of adverse experience left its mark on a different brain region, and in a different mode of processing depending purely on the age at which it occurred,” Korgaonkar said. “I think the main takeaway is that the timing of childhood abuse seems to matter, not just the fact of it.”
“People abused in early childhood and those abused in their teenage years showed distinct patterns of brain activity when processing facial emotions,” Korgaonkar added. “This suggests adversity at different developmental stages leaves different marks.”
The researchers also examined whether these brain changes were tied to specific psychiatric diagnoses or current symptom severity. The increased hippocampal activity in the early childhood abuse group appeared across all clinical diagnoses, suggesting it is a generalized neural signature of early trauma.
“Importantly in our work, these differences showed up across several psychiatric conditions and even after accounting for people’s current symptoms, hinting at a lasting, underlying trait rather than a reflection of how someone happens to be feeling now,” Korgaonkar said. This indicates that early adversity alters underlying emotional hardware rather than just reflecting temporary mood fluctuations.
As with all research, there are some limitations. First, the data relies on participants retrospectively reporting their childhood experiences on a questionnaire. Retrospective recall can sometimes lack precision regarding the exact timing, nature, and severity of the abuse.
“Readers should be aware that our study was a snapshot in time that relied on adults recalling past abuse, which is less precise than following people over many years,” Korgaonkar noted. “We also didn’t measure later adult trauma which could shape these neural signatures. And we also focused on depression, anxiety, and stress disorders so we can’t yet say how far these patterns extend to other conditions.”
Future research should utilize longitudinal designs, which track participants from childhood into adulthood over many years. Following individuals over time would allow scientists to directly observe how the brain changes in real time after an adverse event. “A key next step is confirming these timing effects with more detailed measures of when abuse occurred, ideally in studies that follow people over time rather than relying on recall,” Korgaonkar said.
The research team also plans to expand their focus to encompass broader neural networks. “We’d also like to look beyond isolated brain regions to how emotion-processing networks communicate across the whole brain (this is something we are currently working on), and explore whether these signatures could eventually help tailor treatment, whether it’s knowing when to intervene and with what type of treatment,” Korgaonkar explained.
Moving forward, a deeper understanding of how the brain adapts to trauma at different ages could help medical professionals develop more targeted therapies for survivors of abuse. “Perhaps the most hopeful message is that understanding how and when adversity shapes the brain is a step toward more personalized care,” Korgaonkar concluded.
“It’s also worth emphasizing that these are group-level patterns,” Korgaonkar added. “They describe tendencies across many people, not a diagnosis or destiny for any individual with a history of abuse.”
The study, “Emotional scars: limbic brain processing alterations in adults with childhood abuse across mental health disorders,” was authored by Mayuresh S. Korgaonkar, Cheryl Tobler, Kim Felmingham, Leanne M. Williams, Richard A. Bryant, and Isabella A. Breukelaar.