Scientists today hailed a ‘breakthrough’ after discovering a major potential treatment for postnatal depression.
Until now, experts did not know exactly what causes the condition, despite the fact that one in ten women develop it before or after giving birth.
Researchers in the US and UK have discovered that those affected may be missing genes that allow the body to produce the hormone oxytocin.
Oxytocin is also called the cuddle hormone. It is released during childbirth, breastfeeding and in response to cuddles and stimulates feelings of connection.
Without sufficient amounts, new mothers may struggle to bond with their babies, leading to low mood. Now, experts suggest that developing new oxytocin medications could be a way to combat these symptoms.
Until now, experts didn’t know exactly what causes postpartum depression. But researchers in the US and UK have discovered that some women are missing the gene that helps them produce oxytocin, often called the “cuddle hormone.”
Professor Sadaf Farooqi from the Institute of Metabolic Science at the University of Cambridge said: ‘We have made a breakthrough in understanding postnatal depression, a serious health problem about which very little is known despite decades of research.
‘And more importantly, it could point to oxytocin as a possible treatment for some mothers with this condition.
“This research reminds us that many behaviors we assume we have complete control over have a strong basis in biology.”
The researchers, led by scientists from the University of Cambridge and the Baylor College of Medicine in Texas, made their discovery while studying the genes of two boys from different families.
Both were severely overweight and also suffered from anxiety disorders, autism and behavioral problems.
They discovered that they were all missing one gene, namely TRPC5.
Their mothers also lacked the gene. Both mothers were obese and both suffered from postpartum depression.
When the scientists examined the missing gene in studies with mice, they found that male mice with a defective form of the gene showed the same problems as the male mice.
These included weight gain, anxiety, an aversion to social interactions and aggressive behavior.
Female mice showed similar behavior.
And when they became mothers, they also showed depressive behavior and “decreased care for their offspring,” the experts said.
Writing in the diary CellResearchers said they discovered that TRPC5 acts on nerve cells that produce the hormone oxytocin.
By deleting the TRPC5 gene from these oxytocin neurons, otherwise healthy mice showed signs of anxiety, overeating, impaired social skills and, in the case of the mothers, symptoms resembling postpartum depression.
By making changes to the TRPC5 gene, which increased the production of oxytocin, the scientists were able to ‘reverse’ these symptoms: mice began to behave normally, but lost weight.
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Experts say treatments that increase oxytocin production in the body could produce similar results in humans, but more research is needed.
Oxytocin is produced in the hypothalamus (part of the brain) and secreted into the bloodstream by the pituitary gland.
Research has shown that oxytocin may also have anxiolytic properties, meaning it can reduce feelings of anxiety.
Previous researchers also found that people with autism became more social when given oxytocin through a nasal spray.
Causes of Postpartum Depression Intense feelings of sadness, fear, and exhaustion that usually begin two to three days after birth and can last for months.
Other symptoms include insomnia, loss of appetite, intense irritability and difficulty bonding with the baby.
In rare cases, a serious disorder may develop, namely postpartum psychosis.
Current treatment consists of talk therapy and traditional antidepressants, but these drugs can take weeks to take effect.
The latest NHS data shows that 26 per cent of adults in England are obese and a further 38 per cent are overweight but not obese.
Experts point out that a lack of exercise and a poor diet high in processed foods are the main causes of the obesity epidemic in the UK.
Dr. Yong Xu, an expert in molecular and cellular biology at Baylor College of Medicine, said: ‘What we saw in those mice was quite remarkable.
‘They showed very similar behaviour to that of people who lack the TRPC5 gene, which included signs of depression in mothers and difficulty caring for their babies. This shows us that this gene is causing these behaviours.’
Professor Farooqi added: ‘There is a reason why people with TRPC5 deficiency develop all these conditions.
‘Our work shows that TRPC5 acts on oxytocin neurons in the hypothalamus and plays a crucial role in regulating our instincts.’