Maternal prenatal depression on infant brain development
About prenatal depression
Prenatal depression is common experience affecting around 10–25% of women at any point during their pregnancy. The consequences are far-reaching, and a growing body of evidence suggests children born to ‘stressed’ mothers carry an increased risk of intellectual disabilities and behavioural disorders during childhood. These include neurodevelopmental disorders such as autism and ADHD, along with depression in later life.
As prenatal depression involves complex interactions between social and biological factors, its effect on infant development is poorly understood. Although prenatal depression is widespread, there are no human studies exploring whether infants of mothers with the condition have abnormalities in their limbic system, and research to date has focused solely on animal studies. One theory emerging from such studies suggests the increased transfer of maternal ‘stress hormones’ such as cortisol via the placenta could affect development of ‘limbic’ regions such as the amygdala and hippocampus, which are responsible for the experience and expression of emotion.
Although no-one has researched the abnormalities in the human limbic system, we hope to change this. We recently developed new imaging methods, enabling us to safely and reliably measure healthy infant brain anatomy, including myelination – a process playing a vital role in a normally functioning central nervous system which controls the body and mind.
We aim to develop our work in several ways:
- Carrying out a pilot study of brain anatomy and function of infants aged 4-6 months born to mothers who suffered from prenatal depression
- Testing the main theory by comparing the infants in the pilot study with a second group of infants of non-depressed mothers to see if there is a significant reduction in the volume of limbic structures
- Testing a secondary theory which suggests these infants have (a) reduced myelination of limbic white matter tracts that connect limbic brain regions and (b) increased amygdala activation in response to negative emotional sounds (e.g. crying) and reduced activation to positive sounds (e.g. laughter)
- Carrying out a preliminary investigation of the relationship between any differences we find in the infants and severity of maternal prenatal depression, and cortisol levels
If successful, this pilot will form the basis of future research investigating how maternal depression and other mental health problems affect infant brain development along with the risks for subsequent behavioural abnormalities.