Sonia Lupien Proposes the "Life Cycle Model of Stress"
Fast Breaking Commentary, October 2010
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Article: Effects of stress throughout the lifespan on the brain, behaviour and cognition
Authors: Lupien, SJ;McEwen, BS;Gunnar,
MR;Heim, C |
Sonia Lupien talks with ScienceWatch.com and answers a few questions about this month's Fast Breaking Paper paper in the field of Neuroscience & Behavior.
Why do you think your paper is highly
cited?
I think that this review paper is highly cited because it is the first to propose a link between the different phases of brain development in humans and the impact of stress and/or adversities at these key timepoints. Previous research has suggested that chronic stress and/or adversities may have negative effects on the brain, but these previous studies did not take into account the fact that different brain regions that are sensitive to stress hormones develop at different time in an individual's life.
The hippocampus is almost fully developed by the age of 2 in humans, while the frontal region presents developmental bouts from 8 years of age until late puberty and the amygdala develops until the late 20's. So, chronic stress and/or adversities occurring at these different timepoints should have different effects on the brain and on the brain regions that are developing at the time of stress/adversity.
The paper proposes the "Life Cycle Model of Stress" which takes brain development into account in the effects of chronic stress and/or adversities on the human brain.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
It describes a new model based on the synthesis of knowledge on the effects of stress from the prenatal period to old age, in animals and in humans.
Would you summarize the significance of your paper
in layman’s terms?
"The word 'stress' is overused in the public and it has lost its significance. I think it is time for scientists to 'get out there' and inform the public about what the science of stress has provided in terms of validated scientific data that could be used to develop good and efficient intervention program to teach humans of all ages to deal with the stressors of their life..."
This paper proposes that stress occurring at different times of an individual's life may have very different effects on the brain, based on the time of exposure to the stressor. Given that different brain regions develop at different moments of a child's life, we propose that stress occurring early in life may affect those brain regions that are still developing at the time of exposure to stress.
The effects of stress on these developing brain regions may thus increase the vulnerability of individuals to other stressors later in life and increase their vulnerability to develop stress-related disorders.
How did you become involved in this research, and
how would you describe the particular challenges, setbacks, and
successes that you've encountered along the way?
My first expertise was in cognitive neuroscience and I became interested in stress research because I wanted to understand the effects of stress hormones on human learning and memory. After spending many years studying the effects of stress hormones on human cognition, I realized that what we observe in terms of stress, cognition, and emotion in adulthood may reflect a system that developed much earlier in life, in response to different stressors.
I thus started to study the effects of stress on cognitive and emotional processing in children and one thing that I have realized is that the most important challenge in stress research is the need to take "time" into consideration in the equation linking stress and behavior. We always have to ask ourselves whether what we see today in one adult individual is the result of the acute stressor that this individual is living "today," or whether it is the result of previous exposure of this individual to stress early in life.
"I think that this review paper is highly cited because it is the first to propose a link between the different phases of brain development in humans and the impact of stress and/or adversities at these key timepoints"
If we do not take time into account in stress research, we run the risk of seeing stress as a completely negative event that induces acute disease in humans when in fact, looking at its impact early in life and how a stress response may develop in a child to allow him/her to detect danger and survive may inform us on the real nature and significance of the stress response in humans of all ages.
Where do you see your research leading in the
future?
To new intervention programs in order to educate the public as well as health and education professionals about the science of stress, and in intervention programs to help humans of all ages deal with contemporary stressors. We have spent a significant amount of time studying the negative effects of stress on the body and on the brain. I think we have learned a lot from these studies and that we have enough data at this point to be able to develop good intervention programs.
The word "stress" is overused in the public and it has lost its significance. I think it is time for scientists to "get out there" and inform the public about what the science of stress has provided in terms of validated scientific data that could be used to develop good and efficient intervention programs to teach humans of all ages to deal with the stressors of their life. This is why my team has created the Centre for Studies on Human Stress that is trying to reach this goal.
Do you foresee any social or political
implications for your research?
Absolutely. I perform this type of research BECAUSE it can have a social
and/or political impact. So every day that I work on an experiment with my
team, I tell myself that the results of this study could have an important
impact on the lives of children, parents, individuals of all ages. This is
why the science of stress is so much fun!
Sonia Lupien, Ph. D.
Fernand-Seguin Research Centre
Louis-H. Lafontaine Hospital
Montreal, Quebec, Canada
KEYWORDS: CORTICOTROPIN-RELEASING-FACTOR; PITUITARY-ADRENAL AXIS; REPEATED RESTRAINT STRESS; SMALLER HIPPOCAMPAL VOLUME; RECEPTOR MESSENGER-RNA; PRENATAL STRESS; HPA AXIS; ALZHEIMERS-DISEASE; MAJOR DEPRESSION; GLUCOCORTICOID SECRETION.