This study aims to evaluate the effectiveness and safety of Transcranial Direct Current Stimulation that is tDCS as an adjunctive treatment for patients with bipolar depression. Bipolar depression, the more disabling phase of bipolar disorder, is associated with a high risk of suicide, longer illness duration, and poorer response to traditional treatments. While pharmacological and psychotherapeutic approaches remain the standard, many patients do not achieve complete remission, highlighting the need for alternative strategies. tDCS is a non-invasive, affordable, and safe neuromodulation technique that uses low-intensity electrical currents to stimulate targeted brain regions, particularly the left dorsolateral prefrontal cortex, which is often underactive in depression. This randomized, single-blind, sham-controlled trial will be conducted at DIMHANS, Dharwad, with adult patients aged 18 to 60 who meet ICD 11 criteria for bipolar depression and have a BDI score above 19. Participants will receive either active tDCS or sham stimulation over a minimum of 7 sessions. Depression severity will be assessed using the Beck Depression Inventory, and secondary outcomes will include monitoring for side effects, mood switching checked with  YMRS, cognitive function by MoCA, and quality of life  WHOQOL BREF. The study is expected to recruit 88 participants, accounting for dropout, and statistical analysis will be performed using SPSS software. By generating local data, the study aims to fill a gap in Indian research on tDCS and explore its potential as a safe and effective adjuvant therapy in managing bipolar depression.