As the general population moves towards a greater understanding and awareness of mental illness in campaigns such as Bell Let’s Talk in Canada and Time To Talk in the U.K., scientists, doctors and researchers continue to examine the causes of varying mental disorders in order to improve prevention, screening and treatment.
In the first of its kind, a Canadian study is looking at whether adverse events before birth and in infancy up to two years of age could be biologically embedded into the molecules and genes of the children who may go on to develop a mental illness as an adult – and more importantly, whether it can be prevented.
A synopsis of the ongoing Healthy Foundations Study: A Randomized Controlled Trial To Evaluate Biological Embedding of Early-Life Experience was published in The BMJ in December 2017.
“Findings illustrate that prenatal exposure to maternal stress, postnatal adversity and non-optimal caregiving may exert programming influences reflected in the child’s capabilities to regulate stress and may impact inflammation and DNA,” notes the study.
Exposure to adverse early life experiences such as prenatal stress, poverty, maltreatment, bullying, low-quality care and maternal distress results in increased proinflammatory cytokines. “There is emerging evidence that psychological interventions may have the potential to influence inflammatory markers,” notes the study. A study just published in the American Journal of Obstetrics and Gynecology in January 2018 shows that higher levels of cerebrospinal fluid inflammatory cytokines results in increased odds of a woman developing perinatal depression.
And then there’s the question of genetics and epigenetics – effects on genes that can be passed down to future generations. Researchers are also looking at this question and whether an intervention program can prevent this from happening.
“Emerging evidence suggests that early-life experiences may cause epigenetic modifications of the genome which influence the development of mental and physical health throughout the lifespan,” notes the study, including antenatal depression.
Researchers believe it’s essential to try and prevent long-term negative mental health effects in children earlier rather than later because brain plasticity decreases over time. Researchers believe that “a greater understanding of the biology of early adversity and the potential to mitigate detrimental effects will provide a powerful framework with which to inform basic and applied research, practice and policy.”
Researchers began by recruiting 400 pregnant women from British Columbia who were less than 28 weeks gestation in 2013. Researchers used hair samples from the women to measure physiological stress first at the beginning of the study and then again at two months postpartum. Saliva samples of their infants were collected at two and 24 months to analyze stress and immune function, specifically the effect on the hypothalamic-pituitary-adrenal (HPA) axis.
The HPA axis is located in the brain and is what helps us respond to stress. Studies have shown how prenatal stress has resulted in HPA dysregulation in children. However, studies have also shown how interventions can have a “positive impact on HPA axis functioning in children exposed to adverse experiences including foster care children, adopted institutionalised children, maltreated children, children at risk for antisocial behaviour problems, parentally bereaved children and infants whose mothers were at risk for antenatal depression.”
Previous studies have shown that adverse early experiences can have detrimental effects on adulthood and future generations. Studies of animals as well as humans also show how the nervous system and immune system are altered and the resulting negative effects on brain function which are hard to reverse over time. Researchers in the current study wonder whether these experiences might be biologically embedded and whether a preventative program in pregnancy and postpartum could reverse biological embedding.
The program researchers are using in their study is the home visitation, evidence-based, Nurse-Family Partnership (NFP) program. The program was created to help low-income, first-time mothers under the age of 24 which represents about 5% of live births annually in Canada. Women in this category have been shown to experience higher levels of intimate partner violence, smoking and street drug use, and poor prenatal care with negative mental health effects resulting in their children.
“Children born to these young mothers are at an increased risk for cognitive difficulties, impairment in educational and social outcomes, including school adjustment problems, and poorer physical and mental health outcomes,” the study notes.
Researchers are now in the process of analyzing the data. They believe that if the NFP proves successful at positively impacting children at a biological level, there’s a “greater likelihood of future health” and at convincing policymakers of the “influence of early developmental processes.”
(Jan. 2018), American Journal of Obstetrics and Gynecology, 50: Biomarkers of inflammation in perinatal depression, http://www.ajog.org/article/S0002-9378(17)31699-X/fulltext
(Dec. 2017), The BJM, The Healthy Foundations Study: A Randomized Controlled Trial To Evaluate Biological Embedding of Early-Life Experience, https://www.ncbi.nlm.nih.gov/pubmed/29374668