Navigation Links
Chronic aggressive behavior in boys: Epigenetic sources?

Chronic aggressive behaviour exhibited by some boys from disadvantaged families may be due to epigenetic changes during pregnancy and early childhood. This is highlighted by two studies conducted by a team led by Richard E. Tremblay, professor emeritus at the University of Montreal and Moshe Szyf, professor at McGill University, published in the journal PLOS ONE. The first author of the two papers, Nadine Provenal, was jointly supervised by professors Szyf and Tremblay.

Epigenetic changes possibly related to the prenatal environment

In the first study, published in July, the team found that among men who had chronic aggressive behaviour during childhood and adolescence, blood levels of four biomarkers of inflammation were lower than in men who exhibited average levels of aggressive behaviour in their youth, from 6 to 15 years of age. "This means that using four specific biomarkers of inflammation, called cytokines, we were able to distinguish men with chronic physical aggression histories from those without," says Tremblay, a researcher specializing in developmental psychology. In the second study, it was observed in the same men with aggressive pasts, that the DNA encoding the cytokines showed methylation patterns different from those of the comparison group.

"Methylation is an epigenetic modificationhence reversibleof DNA, in relation to parental imprinting. It plays a role in regulating gene expression", says Szyf, who specializes in epigenetics.

The pre- and postnatal environment could cause these differences in biomarkers associated with chronic aggression," Szyf added. Various studies conducted with animals show that hostile environments during pregnancy and early childhood have an impact on gene methylation and gene programming leading to problems with brain development, particularly in regard to the control of aggressive behaviour.

Previous work by Tremblay's team suggest that men with aggressive pasts have one thing in common: the characteristics of their mothers. "They are usually young mothers at the birth of their first child, with low education, often suffering from mental health problems, and with substance use problems," Tremblay explained. The significant difficulties these mothers experienced during pregnancy and the early childhood of their child may have an impact on the expression of genes related to brain development, the immune system, and many other biological systems critical for the development of their child.

A nearly 30-year follow-up

The blood samples used in the studies published this summer in PLOS ONE were collected from 32 participants who took part in either of two longitudinal studies that begun nearly 30 years ago by Tremblay's team. The first study followed young Quebecers from disadvantaged backgrounds, while the second involved a representative sample of children who were in kindergarten in Quebec in 1986-87.

It is important to note that in disadvantaged families, the rate of boys with chronic aggressive behaviour represents about 4% of the population. This greatly restricts the selection of potential participants. "Once they are adults, they are difficult to find because they have disorganized lifestyles," Tremblay said.

A prevention perspective

This difficulty has not stopped him from pursuing his research further. "We are studying the impact of the socioeconomic environment on the third generation, now that these children are grown up and have children," Tremblay noted. No study has yet been published on the subject, he anticipates "significant intergenerational ties, since we observed an association between parental criminality of the first generation and the behaviour of their children."

Nevertheless, the researcher, who has conducted his work for decades with a prevention perspective, is optimistic. "If our results show that behavioural problems originate from as far back as pregnancy, it means that we can reduce violence through preventive intervention from as early as pregnancy," says Tremblay. We have already shown that support given to families of aggressive boys in kindergarten prevents school dropout and crime in adulthood.


Contact: William Raillant-Clark
University of Montreal

Related medicine news :

1. Chronicling pink slimes fall from grace
2. Adjusting Your Attitude About Chronic Pain May Help You Sleep
3. Chronic cocaine use triggers changes in brains neuron structure
4. Chronic Heartburn May Boost Risk for Esophageal Cancer
5. Should oxygen be used for patients with chronic heart failure?
6. Researchers identify a life-and-death molecule on chronic leukemia cells
7. Understanding the links between inflammation and chronic disease
8. Marker distinguishes more-aggressive from less-aggressive forms of chronic leukemia
9. Study examines chronic inflammation in oral cavity and HPV status of head and neck cancers
10. Recent Report Reveals Dramatic Increase in Chronic Disease in Pets
11. Analysis of KRYSTEXXA phase III data demonstrates improved health-related quality of life and physical function in refractory chronic gout patients
Post Your Comments:
(Date:11/26/2015)... ... November 26, 2015 , ... Indosoft Inc., developer and distributor of the ... to improve system efficiency and reliability. , The new Q-Suite 6 platform is based ... system avoids locking itself into a specific piece of software for many key components ...
(Date:11/25/2015)... ... November 25, 2015 , ... Medical Solutions, one of the ... stellar workplace culture with the company’s Cincinnati office being named a finalist among ... was named a finalist in Cincinnati Business Courier’s 13th annual Greater Cincinnati Best ...
(Date:11/25/2015)... , ... November 25, 2015 , ... For the first ... “ Two Organizations, One Beat ” campaign. The partnership between the two groups began ... aid in MAP International’s cause. , MAP International was founded in 1954 and is ...
(Date:11/25/2015)... ... November 25, 2015 , ... Wimbledon Health Partners, the industry ... Wimbledon Athletics Facebook page to educate the public, parents and school athletic ... 2,000 people under the age of 25 die from sudden cardiac arrest every ...
(Date:11/25/2015)... ... November 25, 2015 , ... Beddit® has launched a new ... systems. The new app features a more intuitive SleepScore™ that rates sleep quality on ... slept. The SleepScore is created by a proprietary algorithm. Beddit analyzes the data to ...
Breaking Medicine News(10 mins):
(Date:11/25/2015)... , Nov. 25, 2015 AAIPharma ... planned investment of at least $15.8  Million to ... Wilmington, NC . The expansion will ... to meet the growing demands of the pharmaceutical ... site expansion will provide up to 40,000 ...
(Date:11/25/2015)... Allergan plc (NYSE: AGN ) today announced that it ... State Attorney General,s Office to end the litigation ... with the Attorney General over the decision of Forest Laboratories, ... the now generic version of memantine immediate release tablets.  Under ... its counterclaims against New York , and ...
(Date:11/25/2015)... USP 800 applies to all healthcare ... pharmacy technicians, nurses, physicians, physician assistants, home healthcare ... covers all entities which store, prepare, transport, or ... institutions, patient treatment clinics, physicians, practice facilities, and ... --> What is the purpose of USP ...
Breaking Medicine Technology: