A team of researchers in the United States has found that children who suffer neglect in their early years are left with physical as well as psychological effects.

The U.S. team found that the lack of a loving caregiver directly affects the body’s production of hormones thought to be important for forming social bonds.

Children raised in harsh orphanage environments in Russia and Romania prior to adoption by American families, were the focus of the study.

The researchers observed significant long-term drops in two hormones known to be key to regulating emotion.

Apparently it was found that the children raised in orphanages had lower levels of vasopressin and oxytocin than others, and this was despite the children later being placed with stable families.

The finding suggests that the effects of early neglect may be to some extent long lasting.

The researchers at the University of Wisconsin-Madison say they believe the failure to receive normal care as a child can disrupt normal development of these hormonal systems which, in turn, can interfere with the calming and comforting effects that typically emerge between children and their caregivers.

When compared with a control group, 18 four-year-old children raised in orphanages showed lower levels of vasopressin in their urine.

The researchers believe this hormone is essential for recognising individuals in a familiar social environment.

The research provides a very powerful approach in looking at the way upbringing and domestic circumstances can effect the way children grow up.

The team organised an experiment where the children were asked to sit on the laps of either their mother (or adopted mother) or an unfamiliar woman and play an interactive computer game.

The game directed the children to engage in various types of physical contact with the adult they were sitting with, such as whispering or tickling each other and patting each other on the head.

This type of interaction between a child and his or her mother would normally cause a rise in oxytocin, and while this was seen in the family-raised children, the orphanage-raised children did not display the same response.

Lead researcher Dr Seth Pollak from the department of psychology at the University of Wisconsin in Madison, says it is extremely important to understand that the work does not imply that these children are in someway permanently delayed.

According to Pollack what it does say is that, in the case of some social problems, this is a window into understanding the biological basis for why the problems happen and how treatment might be designed to address them.

The researchers add that the present data provides a potential explanation for how the nature and quality of children’s environments shape the brain-behavioural systems underlying complex human emotions.

Researchers at Bath University and Bristol University, Dr Julie Turner-Cobb and Dr David Jessop, recently carried out research showing children can be stressed out by their own mothers’ emotional exhaustion.

They found that childcare helped to reduce stress, measured by a hormone present in saliva, among children whose working mothers were in jobs with low satisfaction.

Dr Jessop says there has been a lot of psychosocial work in the past, and now hormonal data is also being brought into play.

Jessop says larger studies over a longer period of time are needed to determine whether children are stressed by their circumstances and whether introducing more social support would help buffer this.

The reports are published in the Proceedings of the National Academy of Science.