These hormones significantly determine the mother-child bond

Mother-child bond decisively controlled by hormones?

Caring for the mother is vital for newborns. But mother-child attachment is impaired in some women, such as in the case of so-called postpartum depression. Here, the interaction of the hormones oxytocin and testosterone could possibly have a decisive influence.

The influence of hormones on the mother-child bond has Sarah Holtfrerich and Jun. Prof. Dr. Esther Diekhof from the Department of Neuroendocrinology at the Institute of Zoology of the University of Hamburg in a recent study. "Different hormones affect maternal feelings," and "while oxytocin strengthens attachment to the child, testosterone appears to suppress maternal behavior," according to the study's findings. These were published in the journal "Scientific Reports".

Babies activate key stimulus in the reward system

Various biological factors affect the responses of adults to babies and toddlers. Here are, for example, the special childlike facial features with big eyes, snub nose and chubby cheeks to call. These typical facial features, also known as child schema, act as a key stimulus in the reward system of the brain and make parents look after the offspring, explain the scientists. However, hormones also have, according to the latest study results, a significant impact on the bond between mother and child.

Analyzes reactions in the brain

In their study, the Hamburg researchers examined 57 subjects, how the two hormones oxytocin and testosterone interact and whether they influence the reactions to the childish schema. Participants were divided into two groups, the first group receiving oxytocin and the second group receiving placebo. Furthermore, test subjects were measured for testosterone levels. The researchers then showed the women pictures of adults and children with different degrees of childlike schema. Functional magnetic resonance imaging (fMRI) was used to record the brain activity of the study participants.

Increased activity in the reward system

"When we administered women with high testosterone levels to oxytocin, the activity in the reward system of the brain increased as soon as they saw baby faces," says Sarah Holtfrerich of the study results. The women also responded more sensitively to the childish scheme after administering oxytocin. According to the researchers, the administered oxytocin had no effect in women with low testosterone levels.

Negative effect of testosterone is compensated

Oxytocin, according to recent studies, apparently counteracts the negative effect of testosterone on mother-child attachment and motivates the caring behavior of the woman. The sex hormones oxytocin and testosterone affect the reward system in the brain, with oxytocin, which is often referred to as a cuddle hormone, strengthening the social bond of the mother to the child, while testosterone is believed to negatively affect maternal behaviors, the researchers emphasize.

Potential for pharmacological research

Since the administered oxytocin had no effect in women with low testosterone levels, the study authors assume that low levels of the male sex hormone in women sufficiently promote maternal behavior and that an additional influence of oxytocin on them is not necessary. In further studies, the researchers now plan to review the results on mothers and fathers. There is also potential for basic pharmacological research, "since an oxytocin deficiency most likely plays an important role in psychiatric disorders such as postpartum depression," according to the Hamburg University Communication. (Fp)