MedicalResearch.com Interview with:
Joshua L. Roffman, MD
Department of Psychiatry
Mass General Hospital
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Autism, schizophrenia, and other serious mental illness affecting young people are chronic, debilitating, and incurable at present. Recent public health studies have associated prenatal exposure to folic acid, a B-vitamin, with reduced subsequent risk of these illnesses. However, until this point, biological evidence supporting a causal relationship between prenatal folic acid exposure and reduced psychiatric risk has remained elusive.
We leveraged the rollout of government-mandated folic acid fortification of grain products in the U.S. from 1996-98 as a “natural experiment” to determine whether increased prenatal folic acid exposure influenced subsequent brain development. This intervention, implemented to reduce risk of spina bifida and other disabling neural tube defects in infants, rapidly doubled blood folate levels among women of childbearing age in surveillance studies.
Across two large, independent cohorts of youths age 8 to 18 who received MRI scans, we observed increased cortical thickness, and a delay in age-related cortical thinning, in brain regions associated with schizophrenia risk among individuals who were born during or after the fortification rollout, compared to those born just before it. Further, delayed cortical thinning also predicted reduced risk of psychosis spectrum symptoms, a finding that suggests biological plausibility in light of previous work demonstrating early and accelerated cortical thinning among school-aged individuals with autism or psychosis.