Childhood trauma has life-long effect on genes and the brain

February 23, 2009

(PhysOrg.com) -- McGill University and Douglas Institute scientists have discovered that childhood trauma can actually alter your DNA and shape the way your genes work. This confirms in humans earlier findings in rats, that maternal care plays a significant role in influencing the genes that control our stress response.

Using a sample of 36 brains; 12 suicide victims who were abused; 12 suicide victims who were not abused and 12 controls, the researchers discovered different epigenetic markings in the brains of the abused group. These markings influence the hypothalamic-pituitary-adrenal (HPA) function, a stress-response which increases the risk of suicide.

This research builds upon findings published last May that showed how child abuse can leave epigenetic marks on DNA.

But, in this, the first study of its kind, Moshe Szyf, a professor in the Department of Pharmacology and Therapeutics; Gustavo Turecki, associate professor in the Department of Psychiatry who practices at the Douglas Mental Health University Institute; Michael Meaney, a professor in the Departments of Psychiatry and Neurology and Neurosurgery, who is also at the Douglas; and McGill postdoctoral research fellow Patrick McGowan have built on their world-renowned epigenetics work to uncover how parental care affects the DNA in the brains of a group of Quebec male suicide victims who suffered abuse as children. The all-McGill study is set to be published in the February 22, issue of the journal Nature Neuroscience.

“We know from clinical experience that a difficult childhood can have an impact on the course of a person’s life”, said Dr. Turecki.

“Now we are starting to understand the biological implications of such psychological abuse,” added Dr. Szyf.

“The function of our DNA is not as fixed as previously believed, said Dr. Meaney. “The interaction between the environment and the DNA plays a crucial role in determining our resistance to stress thus the risk for suicide. Epigenetic marks are the product of this interaction.”

Epigenetics is the study of changes in the function of genes that don’t involve changes in the sequences of DNA. The DNA is inherited from our parents; it remains fixed throughout life and is identical in every part of the body. During gestation and even later in development, however, the genes in our DNA are marked by a chemical coating called DNA methylation. These marks are somewhat sensitive to one’s environment, especially early in life. The epigenetic marks punctuate the DNA and program it to express the right genes at the appropriate time and place.

The researchers discovered that maternal care influences hypothalamic-pituitary-adrenal (HPA) function in the rat through epigenetic programming of certain receptors in the brain. In humans, child abuse alters HPA stress responses and increases the risk for suicide.

In previous studies in laboratory rats, the group proved that simple maternal behaviour such as mothers who licked their pups during early childhood has a profound effect on the epigenetic marks on specific genes and effects on behaviour in ways that are sustained throughout life. However, these effects on gene expression and stress responses can also be reversed in adult life through treatments known to affect the epigenetic mark known as DNA methylation.

The brain samples in the latest study came from the Quebec Suicide Brain Bank, administered by Dr. Turecki of the Douglas Mental Health University Institute. With the support of the Bureau du Coroner du Québec (Office of the Chief Medical Examiner), the McGill Group for Suicide Studies (MGSS) founded the Quebec Suicide Brain Bank (QSBB) at the Douglas Mental Health University Institute, to promote studies on the phenomenon of suicide. Research carried out on brain tissue can help develop intervention and prevention programs to help people suffering mental distress and who are at risk of committing suicide.

Provided by McGill University

Explore further: Why teen suicide is on the rise

Related Stories

Why teen suicide is on the rise

September 8, 2017
Every 40 seconds, another human life is taken by suicide, according to World Health Organization data.

Study shows transgender students are at significant risk for suicidal thoughts

September 5, 2017
Nearly 35% of transgender youth in California reported suicidal thoughts in the past year, almost double that of non-transgender youth, reports a study published in the September 2017 issue of the Journal of the American ...

Researchers investigate genetics of suicide

September 8, 2017
Even today, suicide is a taboo topic often discussed in whispers and swept to the shadows of society, despite it being the leading cause of death among youth in Utah and the tenth leading cause of death in the United States. ...

Increased risk of suicide, mental health conditions linked to sexual assault victimization

August 9, 2017
An analysis of nearly 200 independent studies involving more than 230,000 adult participants finds that having been sexually assaulted is associated with significantly increased risk of anxiety, depression, suicidality, post-traumatic ...

How to get to a world without suicide

August 1, 2017
After his son's suicide aged 18, Steve Mallen sees the world differently. Along with a growing number of mental health experts, he wants to reduce the rate of suicide across the world, and is aiming for zero. Simon Usborne ...

Mental health visits spike prior to burn injury, indicating opportunity for intervention

July 31, 2017
In a new study examining the relationship between mental health and burn injury, researchers note that burn injuries may be preventable through increased access to high-quality mental health care. The study's findings also ...

Recommended for you

Genome editing reveals role of gene important for human embryo development

September 20, 2017
Researchers have used genome editing technology to reveal the role of a key gene in human embryos in the first few days of development. This is the first time that genome editing has been used to study gene function in human ...

A piece of the puzzle: Eight autism-related mutations in one gene

September 19, 2017
Scientists have identified a hotspot for autism-related mutations in a single gene.

Scientists identify key regulator of male fertility

September 19, 2017
When it comes to male reproductive fertility, timing is everything. Now scientists are finding new details on how disruption of this timing may contribute to male infertility or congenital illness.

New assay leads to step toward gene therapy for deaf patients

September 18, 2017
Scientists at Oregon State University have taken an important step toward gene therapy for deaf patients by developing a way to better study a large protein essential for hearing and finding a truncated version of it.

Biologists identify gene involved in kidney-related birth defects

September 18, 2017
A team led by University of Iowa researchers has identified a gene linked to rare, often fatal kidney-related birth defects.

Genomic recycling: Ancestral genes take on new roles

September 18, 2017
One often hears about the multitude of genes we have in common with chimps, birds or other living creatures, but such comparisons are sometimes misleading. The shared percentage usually refers only to genes that encode instructions ...

4 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

albert
3 / 5 (2) Feb 23, 2009
Vaccination and circumcision are the earliest trauma inflicted on a baby. They should be banned entirely.
Mauricio
not rated yet Feb 23, 2009
Babies are exposed to 10 painful "procedures" immediately after they are born. But doctors insist that they will be "fine".
smiffy
1 / 5 (1) Feb 24, 2009
Most regrettably, children make the perfect victims, for they are either incapable or most unwilling to point out their abusers. This is most true in institutions. Coupled with the fact that the children's adult protectors are also incapable or most unwilling to criticise institutional practices, one should therefore expect the greatest level of child abuse to take place in institutions. Sadly, children are receiving more and more institutional exposure, based on the age-old justification that it is 'good for them'.

rubberman
1 / 5 (1) Mar 01, 2009
Albert, Mauricio, the reason these procedures are done as babies, is to remove the emotional attachment that we (humans) have to painful incidents.(Ones that we can actually remember.) Babies cannot remember being circumcized or immunized.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.