Fifteen Eighty Four

Mental illness has a huge impact on individuals, families and communities. Since the brain’s ability to be changed in positive ways is greatest early in life, ill-health of the mother during pregnancy can have a lasting impact on her offspring’s brain development and mental illness risk.

The developmental origins of health and disease (DOHaD) hypothesis states that exposure to poor environmental conditions early in life can increase the risk of health problems across the lifespan. Studies around the world that have tested this theory suggest that unhealthy maternal diet and a lack of physical activity in pregnancy can increase the risk for mental illness in offspring.

However, it remains unclear if we can prevent mental illness (or reduce its severity) by helping pregnant women eat a healthier diet and exercise more. As a result, the full preventive potential of the DOHaD hypothesis has yet to be realized.

The time is now to address this important question and unlock the full potential of the DOHaD hypothesis. Our paper titled: Just DO(HaD) it! Testing the clinical potential of the DOHaD hypothesis to prevent mental disorders using experimental designs, argues the need for testing clinical interventions, particularly those that target maternal diet and exercise during pregnancy, for their ability to reduce the impact of mental health problems in offspring across the lifespan.

While it seems straightforward that healthy diet and exercise in pregnant women would be good for their infant’s brain development, this needs to be proven using study designs that allow for causal conclusions. Current studies in humans linking prenatal diet, exercise and offspring mental disorders are observational in nature and so factors other than diet and exercise (socioeconomic status, genetics) may account for these associations. Experimental study designs (e.g., randomized controlled trials) that randomly assign pregnant women into i) a group that receives a diet+exercise intervention or ii) a ‘pregnancy care as usual group’ are needed since these represent our best chance to determine if these interventions are the cause of beneficial changes in offspring brain development. Further, we argue that pregnancy is the ideal time to conduct these randomized controlled trials with women since they are more likely to make healthy changes during gestation than at any other time in life. Finally, since the brain’s ability to change in positive ways decreases over time, intervening prenatally might lead to impressive gains. If these interventions are shown in experimental studies to positively influence offspring brain development, they could provide the scope for prevention of mental illness across the lifespan.

To support Mental Health Awareness Month Cambridge University Press have curated a collection of free work across a variety of related topics – view the full collection at www.cambridge.org/MHAM19