Even if they are not currently experiencing depressive or manic symptoms, a new study has found that pregnant women with a history of depression or bipolar disorder recognize babies' faces and how they laugh or cry differently than healthy women.
The pilot study, which was recently presented at the ECNP Congress in Barcelona, followed 22 currently well pregnant women with a history of depression and 7 with a history of bipolar disorder and compared them with 28 healthy pregnant women. Between their 27th and 39th weeks of pregnancy, both groups were presented with a series of babies and adults depicting happy or sad faces, as well as expressing laughter and crying. They were all asked to rate how happy or distressed the babies were based on their facial and vocal displays of emotion as well as identify adult emotions based on their facial expressions.
Unlike healthy pregnant women, researchers found that pregnant women with a history of bipolar disorder struggled to recognize all facial expressions. In addition, they showed what was referred to as a "positive face processing bias", which means they had an easier time recognizing happy adult faces and had more positive ratings of happy infant faces.
Pregnant women who had a history of depression, on the other hand, were found to show a negative bias, meaning they were unable to recognize happy adult faces as well and rated infant cries more negatively.
According to the study, these findings may represent an early risk factor for the children of these women.
"These differences may impair these women's ability to recognise, interpret and respond appropriately to their future infants' emotional signals," said Dr. Anne Bjertrup, the study's lead researcher.
Nearly eight per cent of Europeans reported suffering from depression in the previous 12 months, and around one per cent have reported suffering from bipolar disorder. The rate of depression in women is much higher than that in men - in fact, it's around 50 per cent higher. With over 5.1 million births in the European Union each year, statistically, many women who become pregnant will have one, or both of these disorders.
Experts like Professor Eduard Vieta from The Institute of Neuroscience at the University of Barcelona, believe that studies like this will help improve the lives of people - particularly women - living with depression and bipolar disorder.
"This work may help us identify targets for pharmacological and psychological treatments, which in turn may help people with depression and bipolar disorder," he said.