[Depressive symptoms in a sample of women with subclinical hypothyroidism and their relationship to chlorates in tap water].

Introduction: depressive symptoms may develop in subclinical hypothyroidism and their presence usually facilitates recognition and the establishment of replacement treatment; however, recent studies have found no association between the two. Besides, thyroid function can be affected by endocrine disruptors and some of them, such as chlorates, can be found in the water we drink. Objectives: to know if the type of water consumed may influence the development of depressive symptoms in patients with subclinical hypothyroidism. Methods: 96 women with subclinical hypothyroidism, without thyroid treatment, were enrolled. We studied, among other variables, the presence of depressive symptoms, type of water consumption (tap, bottled or spring) and the level of chlorates in the tap water. Results: 41.7 % (40) of women presented depressive symptoms and these were related to the consumption of tap water (p = 0.001), resulting in a reliable predictor (OR, 27.79; p = 0.007). Chlorate level in the tap water was 250 µg/L, a value within the maximum limit allowed by law. Conclusions: chronic exposure to chlorates in water, in women with subclinical hypothyroidism, at levels authorized by law, could favor the inhibition of iodine transport and the appearance of depressive symptoms. It would be interesting to test this hypothesis as well as its possible effect on other population profiles.