Of the rats used for the study, those not exposed to stress showed an increase in brain cell connections in areas connected to learning, memory and mood.
Conversely, the brains of mother rats that were stressed twice a day – by being placed in water or being restricted in their mobility – didn’t show an increase.
Assistant Professor of psychology and neuroscience, Dr Leuner, said: ‘Animal mothers in our research that are unstressed show an increase in the number of connections between neurons. Stressed mothers don’t. We think that makes the stressed mothers more vulnerable. They don’t have the capacity for brain plasticity that the unstressed mothers do, and somehow that’s contributing to their susceptibility to depression. And they were not very good mothers.
Dr Leuner went on to say: ‘It’s devastating not only for the mother, because it affects her well-being, but previous research also has shown that children of depressed mothers have impaired cognitive and social development, may have impaired physical development, and are more likely as adults to have depression or anxiety. A better understanding of postpartum depression is important to help the mother but also to prevent some of the damaging effects that this disorder can have on the child.’