We studied the association between the ASMT rs4446909 variant and sleep/activity, as assessed with the Pittsburgh Sleep Quality Index (PSQI) and by actigraphy, in 53 subjects (25 patients with BD in remission and 28 healthy controls).
A replication study and a meta-analysis using 480 independent patients with BD and 672 controls confirmed the significant association between rs4446909 and BD (P= 0.002).