Analysis revealed no significant effect of mood disorder diagnosis on nAChR number (F(1,17) = 0.224, p = 0.673) or an interaction of nicotine × mood disorder (F(1,17) = 0.04, p = 0.836) measured by equilibrium ligand binding (Fig. 1A), which is in agreement with previous assessments of nAChR number in postmortem human cortical tissue from individuals with major depression or bipolar disorder (Saricicek et al., 2012; Hannestad et al., 2013). Here, CHRNA4 is linked to bipolar disorder.