Abstract
Background
Evidence from animal and human studies indicates that thyroid hormone deficiency during early gestation alters brain development. As schizophrenia is associated with prenatal brain insults and premorbid cognitive deficits, we tested the a priori hypothesis that serologically defined maternal thyroid deficiency during early to mid-gestation is associated with offspring schizophrenia. Methods: The investigation is based on the Finnish Prenatal Study of Schizophrenia (FiPS-S), a nested case-control study that included archived maternal sera from virtually all pregnancies since 1983 (total N over 1 million). We identified all offspring in the cohort diagnosed with schizophrenia based on the national inpatient and outpatient register and matched them to comparison subjects (1:1) from the cohort on sex, date of birth, and residence in Finland at time of onset of the case. Maternal sera on 1010 case-control pairs were assessed for free thyroxine (fT4) and 948 for thyroid stimulating hormone (TSH).
Results
Maternal hypothyroxinemia (fT4 ≤10th percentile, normal TSH) was associated with an increased odds of schizophrenia (OR=1.75, 95% CI=1.22 – 2.50; p=0.002). When adjusted for maternal psychiatric history, province of birth and maternal smoking during pregnancy, the association remained significant (OR=1.70, 95%CI 1.13 – 2.55; p=0.010). Conclusions: In a large, national birth cohort, prospectively documented early to mid-gestational hypothyroxinemia was associated with increased odds of schizophrenia in offspring. This can inform translational studies of maternal hypothyroxinemia examining molecular and cellular deviations relevant to schizophrenia.
http://www.biologicalpsychiatryjournal.com/article/S0006-3223(15)00520-X/abstract?rss=yes