Furthermore, we identified two other thyroid hormone metrics, FT3 and FT3/FT4, that had suggestive causal associations with Type 1 bipolar disorder yielding IVW ORs of 1.18 (95% CI: 1.03, 1.35, p value = 1.55 × 10−2) and 1.97 (95% CI: 1.02, 3.82, p value = 4.46 × 10−2) respectively (Table 1); these associations were directionally consistent across MR methods (Table 1 and Figure 1). The gene discussed is TG; the disease is bipolar disorder.