A new study by the University of Wisconsin-Madison reveals evidence that early life stress in children can lead to developmental and behavioral problems later in life.

Early life stress (ELS), such as physical abuse, early neglect, and poverty, can physically alter parts of the developing brain that are most involved in decision-making, learning, memory and reaction to stress and emotion, according to the study.

ELS is believed to also lead to physical manifestations including depression, anxiety, heart disease and cancer.

The study may help parents, educators, sociologists and others. It is the first step in unraveling a process in brain development that is not yet well understood, according to Seth Pollak, co-leader of the study and UW-Madison psychology professor.

"We haven't really understood why things that happen when you're 2, 3, 4 years old stay with you and have a lasting impact," said Pollak.

Some of the long-term effects are thought to be related to behavior, education and employment success, health, ability to cope with stress and even affect forming romantic relationships.

The study covered 128 children approximately 12 years old. These children were ELS-impacted, coming from households with low socioeconomic status or suffering from physical abuse and/or neglect in their early years.

Researchers interviewed these children and their caregivers. They also took brain scans of the children and hand-measured their hippocampus and amygdala regions.

These two regions of the brain, which are primarily responsible for processing emotion and stress, were shown to be most affected by ELS.  Both regions were found to be smaller in children who were considered members of the ELS group. The smaller size of these areas could be an indicator of reduced processing ability, leading to the issues associated with ELS later in life. A control group of children who were not considered to have dealt with ELS were also tested; the hippocampus and amygdala regions in their brains were found to be normal in size.

"For me, it's an important reminder that as a society we need to attend to the types of experiences children are having. We are shaping the people these individuals will become," said Pollak.

The researchers cautioned that the findings are just markers for neurobiological change, and that the brain is resilient and highly adaptive to stress, and that the presence of physical changes in the brain do not necessarily predetermine the outcome.

The study is published in the journal Biological Psychiatry.