Lithium is the primary medication for Bipolar Disorder (BD). In women with BD, lithium is effective postpartum, but breast-feeding for medicated mothers is controversial because of harmful effects for her child. At present, the biological mechanisms of lithium are not well understood, affecting its usage and overall health implications. We showed that breast-fed infants (rats) exposed to lithium via breastmilk, even with the mother on a sub-therapeutic dose, experienced weight gain and reduced blood thyroid hormone levels. These are symptoms of hypothyroidism, which is frequently seen in BD patients. We further showed that lithium inhibited iodine uptake by the thyroid, initiating a molecular mechanism leading to reduced thyroid hormone production. Importantly, infant thyroid function can be significantly improved by administering supplementary iodine to the medicated mother’s diet during breast-feeding. This study has elucidated the mechanisms of lithium in thyroid function, provided valuable information on use postpartum, and found a clinically applicable remedy to side-effects. The results are particularly important for patients (and their infants) who respond well to lithium and need, or choose, to breast-feed. This multi-national study led by the City University of Hong Kong will soon appear in top psychiatry journal Bipolar Disorders.
Read more at Bipolar Disorders: https://onlinelibrary.wiley.com/doi/10.1111/bdi.13047
28 Jan 2021