A new study has discovered that stress in early childhood leads to faster maturation of certain brain regions during adolescence.
In contrast, stress experienced later in life leads to slower maturation of the adolescent brain, according to a long-term study conducted by researchers at Radboud University in the Netherlands.
For the study, researchers monitored 37 subjects for almost 20 years.
In 1998, the group — which then was made up of 129 one-year-olds and their parents — was tested for the first time.
Over the past 20 years, researchers studied the children’s play sessions and interactions with parents, friends, and classmates. The children were also subjected to MRI scans.
The data allowed Karin Roelofs, professor of experimental psychopathology, her Ph.D. student Anna Tyborowska, and other colleagues at the university to investigate how stress in various stages of life affected the adolescent brain of these children.
More specifically, the researchers looked at the effects on cerebral maturation.
The researchers investigated two types of stressors — negative life events and negative influences from the social environment — in two life stages of their subjects: Early childhood (0-5 years) and adolescence (14-17 years).
They related these stress levels to the maturation of the prefrontal cortex, amygdala and hippocampus. These brain regions play an important role in functioning in social and emotional situations and are known to be sensitive to stress, researchers noted.
According to the study’s findings, stress due to negative experiences during childhood, such as illness or divorce, appears to be related to faster maturation of the prefrontal cortex and amygdala in adolescence.
However, stress resulting from a negative social environment during adolescence, such as low peer esteem at school, is connected to slower maturation of the hippocampus and another part of the prefrontal cortex, the study discovered.
“Unfortunately, in this study we can’t say with certainty that stress causes these effects,” Tyborowska said. “However, based on animal studies, we can hypothesize that these mechanisms are indeed causal.”
“The fact that early childhood stress accelerates the maturation process during adolescence is consistent with theories of evolutionary biology,” she continued. “From an evolutionary perspective, it is useful to mature faster if you grow up in a stressful environment. However, it also prevents the brain from adjusting to the current environment in a flexible way. In other words, the brain becomes mature too soon.”
The researchers were surprised to find, however, that social stress later in life seems to lead to slower maturation during adolescence.
“What makes this interesting is that a stronger effect of stress on the brain also increases the risk of developing antisocial personality traits,” Tyborowska said.
Tyborowska is now conducting the eleventh round of measurements, with the subjects now in their 20s.
“Now that we know that stress affects the maturation of brain regions that also play a role in the control of emotions, we can investigate how this development continues later in life,” she said.
The study was published in Scientific Reports.
Source: Radboud University