Many studies conducted in non-pregnant states reported a positive association between either overt (Thomsen et al., 2005; Panicker et al., 2009; Ittermann et al., 2015) or subclinical (Monzani et al., 1993) hypothyroidism or autoimmune stigmata of thyroiditis (positive anti-TPO antibodies) with anxiety (Monzani et al., 1993; Carta et al., 2004), whereas others did not (Engum et al., 2002, 2005; Eaton et al., 2010). Here, TPO is linked to thyroid gland disorder.