Bipolar Patients who remitted after 3 months of treatment for depression have higher binding potential of [11C]WAY-100635 in the brain than patients who did not remit (p = 0.02), likely reflecting higher 5HT1A receptor levels. Healthy control subjects are included here as a reference. VPFC = ventral prefrontal cortex, ACN = anterior cingulate cortex, CIN = posterior cingulate cortex, AMY = amygdala, HIP = hippocampus, PHG = parahippocampal gyrus, INS = insular cortex, TEM = temporal cortex, PAR = parietal cortex and OCC = occipital cortex. Standard errors (SE) were computed for each BPF value using a bootstrap algorithm that takes into account errors in metabolite, plasma and brain data; observations were weighted accordingly.