Whenever a stress response is triggered, the hypothalamus at the base of the brain is activated and stimulates the pituitary gland, which in turn helps regulate the activity of other hormone-secreting glands. As the mediator of stress management, the pituitary gland may be highly affected by stress dysregulation.
A recent study carried out at the University of Melbourne, Australia, investigated the relationship between different types of early life stress and the size of the pituitary gland. The investigators followed 91 subjects from the age of 11 to 19 years old, collecting data every two years.
At these four time points, the participants completed several questionnaires. They provided information regarding the frequency of the stressful events they had experienced (chronic or occasional) and the type of childhood maltreatment they had suffered (physical, emotional and sexual abuse, or physical and emotional neglect). Towards the end of the study, they underwent MRI scans. Each pituitary gland was traced and its volume was measured using Analyze software by summing all voxels within the traced region.
As the researchers had hypothesized, adverse early-life experiences turned out to be associated with larger pituitary gland volumes in adolescence. While childhood maltreatment increased pituitary gland development only in females, maternal distress affected its size in both genders. This data provides additional evidence for sex-differences in the anatomy of the pituitary gland.
Furthermore, chronic stress experiences, but not occasional ones, were found to be related to the volume of the gland. That is, while only recurring events, such as maltreatment and negative maternal behavior, may impact the maturation of the gland, sporadic stressful life events may not have any consequences on this structure.
Findings from this longitudinal study shed light on the stress-induced enlargement of the pituitary gland and draw attention to a potential link between this abnormal development and the progression of mental disorders.Brain Studies, Neurodevelopment, Stress