RecruitingDevice studyDeveloping Brain Imaging Analysis Expertise for Personalizing Transcranial Electric Stimulation in Anhedonia Treatment of Patients With Bipolar DepressionThe purpose of this study is to investigate whether transcranial direct-current stimulation (tDCS) will engage reward-related brain circuitry, more specifically the uncinate fasciculus (UF) tract, which connects the orbitofrontal cortex (OFC) and nucleus accumbens (NAcc) regions. Also to evaluate whether the changes in the fractional anisotropy (FA) of the UF tract are associated with changes of clinical symptoms of anhedonia and finally to investigate the moderation role of simulated electric fields (EFs) in an association between FA of the UF and symptoms of anhedonia.