How childhood stress impacts brain's growth

Childhood stress can cause faster maturation of brain during adolescence, finds a study.

In contrast, researchers of Radboud University concluded that stress experienced later in life leads to slower maturation of the adolescent brain.

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.

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 brain area hippocampus and another part of the prefrontal cortex.

"Unfortunately, in this study we can't say with certainty that stress causes these effects. However, based on animal studies we can hypothesize that these mechanisms are indeed causal," said Anna Tyborowska.

"The fact that early childhood stress accelerates the maturation process during adolescence is consistent with theories of evolutionary biology," added Tyborowska.

"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 become "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," concluded Tyborowska.

The study has been published in the journal Scientific Reports.