About one in seven new mothers suffer from postnatal depression (PND), a condition that usually starts about two weeks after childbirth. A simple, accurate blood test to determine which women may be most at risk could soon be developed due to the discovery Warwick University researchers’ made when they examined women for specific genetic variants.
The study was presented at the International Congress of Endocrinology/European Congress of Endocrinology by Professor Dimitris Grammatopoulos, Professor of Molecular Medicine at Warwick’s University. He explains, “Current screening policies rely on the opportunistic finding of PND cases using tools such as the Edinburgh Postnatal Depression Score (EPDS), but such tests cannot identify women at risk, ahead of them developing the condition.”
The team evaluated 200 pregnant women for PND using the EPDS once during the women’s first antenatal clinic visit, with a second assessment following within two to eight weeks after giving birth. The researchers discovered that those who developed PND had a higher likelihood of having specific genetic variants, including the bcl1 and rs242939 single nucleotide polymorphisms (SNPs) of the glucocorticoid receptor and the corticotrophin-releasing hormone receptor-1 genes.
These receptors are involved in controlling the activity of the hypothalamo-pituitary adrenal (HPA) axis, which is an endocrine system that is activated in response to stress. One of the most important functions of the hypothalamus is to link the nervous system to the endocrine system via the pituitary gland which releases a number of hormones into the blood stream that control vital body functions. The findings seem to indicate that PND may be a particular subgroup of depression with a distinct genetic element. This would mean that some women might genetically react stronger to environmental factors that trigger depression than others.
Professor Grammatopoulos went on to say, “Although we knew already that there was an association of the HPA axis with depression, ours is the first study to show a link between specific elements of this pathway and the particular case of PND. We now intend to conduct further research on other genetic variants of the HPA axis in a larger, multi-centre study involving women from Coventry, Birmingham, and London. We think that we have made an important step forward in characterizing the prospective risks and are therefore paving the way for timely, appropriate medical treatment for women who are likely to develop PND.”
PND should not be confused with having the ‘baby blues’, which is a milder, more temporary condition. PND is a serious condition with symptoms, such as sadness, crying episodes, changes in eating and sleeping patterns, reduced libido, anxiety and irritability that can have a substantial effect on the children. For instance, mothers that are depressed tend to show their children less affection; they usually engage in less play with their children and may use less ‘baby talk’, which is designed to capture a child’s attention. Insufficient mother-child interaction may result in the children suffering from learning and emotional difficulties in later life.
The researchers state that the role of the HPA axis in this type of depression has not been proved until now, even though it appears evident that PND may be caused due to some form of hormonal imbalance.
Professor Grammatopoulos concluded, saying, “We believe that we have made a discovery with important clinical and social implications. If we can identify women likely to suffer from PND in advance so that they can be treated appropriately and at an early stage, we will have improved the lives not just of the parents, but also of their children.”