Scientists call for more animal research to shed light on postnatal depression

Animal research could play a greater role in identifying why 1 in 5 new mothers experience high levels of anxiety and depression in the days after giving birth, according to two pharmacologists.

Dr David Slattery and Dr Clara Perani believe that while the latest evidence indicates that these distressing responses to motherhood are still poorly understood, animal research could provide valuable clues to their causes.

“All female mammals give birth, produce milk and adapt their behaviour in order to care for the offspring," said Dr Slattery.

"Research in rodents shows that they too experience a host of important behavioural and physiological alterations during this time. For example, just like most breastfeeding mothers, rodents are generally calmer and show a smaller increase in the stress hormone cortisol when subjected to stress."

Anxiety, depression and psychosis during this postpartum period of life not only affect the wellbeing of the mother but can also place at risk the long-term health of the infant, according to the doctors. Infant care and bonding can also be altered, which in turn may lead to long-term behavioural and emotional problems for the child, added Dr Perani.

Improve understanding of postpartum psychology
Factors like smoking, drinking alcohol throughout pregnancy and marital status all influence the likelihood of a mother developing postpartum mood and anxiety disorders, and having a previous history of a mood condition places a woman at greater risk too.

While it is understandably very difficult to impose experimental restraints on women, some factors such as diet or repeated exposure to stress during pregnancy can be explored in research involving animals. Identification of such causes could lead to better treatment and faster diagnosis of the disorders, which would help both mother and child.

Dr Slattery concluded: "What we need now is a greater understanding of the underlying causes and mechanisms so that we can begin to identify mothers who are at risk and start to provide them with preventative advice and effective therapies.

"Long-term, we hope that increased study, involving both animals and humans, will improve our understanding of postpartum psychiatric disorders, and lead to improved, earlier diagnosis and to novel treatment approaches for this particular time period of a woman’s life."