Paper Summaries
Article #1:
Korgaonkar M., Antees C., Williams L., Gatt J., Cohen R., Paul R., O’Hara R., Grieve S., Early Exposure to Traumatic Stressors Impairs Emotional Brain Circuitary, 2013, PlosOne, 8:9
Mayuresh S. Korgaonkar, an associate professor and medical researcher, along with other researchers performed a study to determine the effects of early life trauma on cortical thickness, specifically on the cingulate and limbic emotion brain circuitry. They hypothesized that the participants with high early life trauma exposure would show reduced cortical thickness, anterior cingulate and amygdala-hippocampal volume, and reduced micro-structural integrity of the corresponding white matter pathways. These alterations correlate with symptoms of depression and anxiety. In addition, they hypothesized that different age groups will have different alterations since their brains will be developed differently at a specific age. To perform the study, 352 participants ranging from 6 years of age to 78 years of age, brains were scanned and compared to determine any reduction of the brain regions that were listed. Before scanning the participants, they took an early life trauma questionnaire to assess their exposure to early life stressors. The brain images were acquired through an MRI and then the boundary between the gray and white matter were segmented to measure cortical thickness and the volume of white matter. Diffusion Tensor Imaging was used to determine any alterations on the cingulate and limbic emotion brain circuitry. As a result, cortical thickness was reduced in adolescents that have had exposure to early life trauma, reduced volume of the amygdala was found within adults that had exposure to early life trauma, and no alterations were found in the limbic cingulate white matter tracts across all ages.
Article #2:
Teicher M., Dumont N., Ito Y., Vaituzis C., Giedd J. and Anderson S., Childhood Neglect is associated with reduced corpus callosum area, 2004, Biological Psychiatry, 56:2, 80-85
Martin H. Teicher along with other researchers performed a study to the effects of childhood abuse or neglect on the anatomy of the corpus callosum. The corpus callosum is fiber tract that connects the right and left hemisphere of the brain and functions in movement and cognitive abilities. Alteration of the corpus callosum has been correlated with instability, impulsivity, and different mental disorders. They hypothesized that children who suffered abused will have a smaller corpus callosum. To perform the study, 51 pediatric patients were screened for psychiatric evaluation and scanned through an MRI to compare their brain images to 115 healthy participants. 26 of the 51 pediatric patients were boys and the other patients were girls. As a results, the corpus callosum of abused patients was 17% smaller than the corpus callosum in the control patients. In boys, neglect seemed to have the greatest factor in corpus callosum reduction and sexual abuse had the greatest affect in corpus callosum reduction in the girl participants. The researchers noted that although they did find a reduction in the size of the corpus callosum within children who have been abused or neglected, these results do not indicate a cause-and-effect relationship since there can be other reason as to why the patients had a smaller corpus callosum.
Article #3:
Paul R., Henry L., Grieve S., Guilmette T., Niaura, Niaura R., Bryant R., Bruce S., Williams L., Richard C., Cohen R., and Gordon E., The relationship between early life stress and microstructural integrity of the corpus callosum in a non-clinical population, 2008, Neuropsychiatric Disease and Treatment 4:1, 193-201
Robert Paul and other researcher performed a study to examine the relationship between early life stress and alterations to the microstructural integrity of white matter in the brain. They hypothesized that individuals exposed to early life stress exposure. They examined the relationship between the exposure of early life stress and volume of the genu, body, and splenium of the corpus callosum. 115 subjects that were older than 18 participated in the study. They completed a questionnaire to assess their exposure to early life stress as well as traumatic experiences. Each participant’s brain was scanned to get a neuroimage and processed through a Diffusion Tensor Analysis to define measure the integrity of the white mater with a FA scale. After analyzing the images, FA values were significantly reduced in the genu of the corpus callosum in individuals that were exposed to early life stress. In addition, a greater reduction in FA values were found in participants that are female rather than men. Their results were consistent with other studies that examined early life stressors and the rostral anterior regions of the brain. Although the study did show results that correspond to their hypothesis, the researchers noted that the findings cannot prove a causal relationship due to alternative hypothesis and limitations of the study.
Article #4:
Mehta M., Golembo N., Nosarti C., Colvert E., Mota A., Williams S., Rutter M., and Sonuga-Barke E., Amygdala, hippocampal and corpus callosum size following severe early institutional deprivation: The English and Romanian Adoptees Study Pilot, 2009 Journal of Child Psychology and Psychiatry, 50:8, 943-951
Mitul A. Mehta and other researchers examined the relationship between brain volume and early institutional deprivation in children. They examined children who were living in deprived conditions in Romanian state institutions. The researchers hypothesized that the sizes of the corpus callosum, amygdala, and hippocampus will be affected in the children that lived in the Romanian state institution. 14 children that were adopted from the Romanian state institution and 11 non-adopted children acting as a control group participated in the study. All of the participants had a MRI scan and the volumes of the corpus callosum, amygdala, and hippocampus were measures from the images. The researcher found that the children from the Romanian institution had grey and white brain matter that was reduced by 15% and 18% and a reduced hippocampal volume than the control group. In addition, the children from the institution had increased amygdala volumes compared to the control group. There was no significant difference in the volumes of the corpus callosum between the children from the institution and the control group.
Article #5:
Graziano R., Bruce S., and Paul R., The Corpus Callosum and PTSD Severity, 2019, 36:15, 7480-7494
Robert Graziano and other researchers examined the effects of interpersonal violence on the integrity of the corpus callosum in women. They defined interpersonal violence as trauma from sexual abuse, childhood abuse, sexual assault, and domestic violence. They hypothesized that women who meet the criteria for PTSD will display lower a lower FA score in their corpus callosum, and the lower FA score in the corpus callosum will correspond with reexperiencing symptoms of unwanted memories, nightmares, and flashbacks. 60 right-handed women with a diagnosis of PTSD resulting from interpersonal trauma and 18 right-handed women that do not have a diagnosis of PTSD participated in the study. They specially asked right-handed women for their participation because handedness has been linked to brain laterization and differences in laterization could mix up results. The women’s brains were scanned using an MRI and measured through diffusion tensor imaging to examine the corpus callosum’s FA value. The researchers found that the women diagnosed with PTSD had a higher FA value in the genu of the corpus callosum than the women who do not have a diagnosis of PTSD. Although their results did not match their hypothesis, the higher FA value in the genu of the corpus callosum is consistent with the symptoms of unwanted memories, nightmares, and flashbacks.
Article #6:
Anderson S., Tomada A., Vincow E., Valente E., Polcari A., Teicher M., Preliminary Evidence for Sensitive Periods in the Effect of Childhood Sexual Abuse on Regional Brain Development, 2008, Neuropsychiatry, 20:3, 292-301
Susan Anderson and other researchers performed a study to test their hypothesis of stress-sensitive brain regions have their own developmental time windows when they are vulnerable to the effects of stress. In addition, they sought to propose a strategy to facilitate the exploration of sensitive period effects for trauma such as sexual abuse. They researchers predicted that the hippocampus would have an early period of vulnerability. 26, 18–22-year-old women who have a history of childhood sexual abuse at different ages and 17, 18-22-year-old women who do not have a history of childhood sexual abuse participated in the study. An MRI was used to scan the participant’s brains, and they measured the hippocampus, corpus callosum, frontal cortex, and amygdala size of each participant. The participants were characterized by the age and years they experienced their sexual abuse to detect the windows of vulnerability of the brain regions. After the study, the researchers found that sexual abuse at the 3-5- and 11-13-years old range was associated with reduced hippocampal volume, sexual abuse at the 9-11 years old range was associated with a reduction in the corpus callosal area, and sexual abuse at the 14-16 years old range was associated with a reduction of the frontal cortex volume. These results correlated with their hypothesis that the hippocampus would have an early period of vulnerability to stress.
Article #7:
Wong T., Moore T., Seidlitz J., Yuen K., Ruparel K., Barzilay R., Calkins M., Alexander-Bloch A., Satterthwaite T., Gur Raquel., Gur R., Traumatic Stress load and stressor reactivity associated with accelerated gray matter maturation in youths indexed by normative models, 2023, Molecular Psychiatry, 28, 1147-1145
Ting Wong and other researcher sought to understand how traumatic stress affects typical brain development during adolescence plays a role in maladaptive brain function and resilience. They performed a study to map deviations from normal ranges of grey matter of the brain of adolescents that have been exposed to trauma. They hypothesized that accelerated brain maturation moderates the association between traumatic stress loads and poor cognitive function and psychopathology. Another hypothesis of the study is that a high stressor reactivity score will be associated with accelerated brain maturation while a low stress reactivity score will be associated with slow brain maturation. To test their hypotheses, 1374 patients who received medical care at the Children’s Hospital of Philadelphia participated in the study. 1129 of the 1374 participants experienced psychopathology at least one traumatic stressful event and the other 245 participants did not experience a traumatic event or any psychopathology. Each of the participants received an MRI scan to get images of their brains. Grey matter was measured by cortical thickness, and volume and density of cortical regions. The researchers found that a high the participants that had a high traumatic stress load was positively associated with poorer cognitive functioning and greater psychopathology which were mediated by accelerated gray matter maturation. IN addition, high stressor reactivity scores were correlated with greater acceleration of gray matter maturation.
Article #8:
Lindauer R., Booij J., Habraken B., Van Meijel E, Uylings H., Olff M., Carlier I., Heetan G., Van Eck-Smit B., and Gersons B., Effects of psychotherapy on regional cerebral blood flow during trauma imagery in patients with post-traumatic stress disorder: a randomized clinical trial, 2007, Psychological Medicine, 38:4, 543-554
Lindauer and other researchers performed a study to test their first hypothesis their hypothesis that trauma-related stimuli in PTSD results in higher activation of the temporal and the dorsolateral prefrontal cortex, and lower activation of the medial prefrontal cortex. Their second hypothesis of the study was that effective psychotherapy influences regional blood flow in the prefrontal cortical regions. 24 Dutch patients with a diagnosis of PTSD and 15 healthy control subjects participated in the study. To test their first hypothesis, the researchers played a script with a traumatic event for the participants to listen to for 10 minutes and asked to visualize the events while the researchers used a brain-dedicated SPECT camera to measure their blood flow. To test their second hypothesis, the participants attended 16 weekly psychotherapy sessions that were 40-60 minutes each. After the study, greater activation was found in the right insula and right superior/middle frontal gyrus in the patients diagnosed with PTSD. Lower activation in the right middle/frontal gyrus was found after effective psychotherapy.
Article #9:
Delaney S.W., Xerxa Y., Muetzel R.L., White T., Haneuse S., Ressler K.J., Tiemeier H., Kubzansky L.D., Long-term associations between early-life family functioning and preadolescent white matter microstructure, Psychological Medicine, 53:10, 4528-4538
Scott Delany and other researchers performed a study to test their hypothesis that more positive prenatal and mid-childhood family functioning would be associated with higher global fractional anisotropy (FA) and lower global mean diffusivity (MD) during neurodevelopment. 2,727 families answered questionnaires about their family functioning prenatally and when their child was in their mid-childhood. The questionnaires included questions about how supportive their families were and how their general feelings about their families were. Once their children were around 10 years old, the researchers performed a diffusion weighted imaging to measure water mobility within the brain tissue. After the study, the researchers found that positive pre-natal functioning was associated with a higher global FA and a lower global MD in preadolescents. Although this only partly matches their hypothesis, their results still suggest that high functioning prenatal family environments may benefit their child into preadolescence.
Article #10:
Kokubun K., Nemoto K., Oka H., Fukuda H., Yamakawa Y., Watanabe Y., Association of Fatigue and Stress with Gray Matter Volume, 2018, Frontiers in Behavioral Neuroscience, 12,
Kokubun and other researchers performed a study to investigate the relations between the gray matter brain healthcare quotient (GM-BHQ) of healthy participants three stress scales. They hypothesized that the (GM-BHQ) might be associated with stress or fatigue. To perform the study, 63 healthy participants, 34 females and 29 males, were recruited in the study. The Profile of Mood States, Perceived Stress Scale, and Chalder Fatigue Scale questionnaires were given to the participants. The participants were then scanned with an MRI to get images of their brains. After the study, the researchers found that fatigue that was measured by the Profile of Moods questionnaire correlated with a lower GM-BHQ and even more significantly when it interacts with stress. This suggests that stress and fatigue play a role in the reduction of grey matter volume of the brain.