Frontal cortex activity is reduced in the left hemisphere during depression. Transcranial direct current stimulation is a non-invasive neuromodulation technique that can increase frontal cortex activity. Therapy based on transcranial Direct Current Stimulation and positive psychology therapy was applied for improving patients' quality of life. The present study compared three conditions of subjects with clinical depression; (a) transcranial Direct Current Stimulation therapy, (b) positive psychotherapy, and (c) combined treatment. Hamilton Depression Rating Scale, Adult State Hope Scale and Optimism/Pessimism Scale was used at baseline, 2-week, 4-week, and 3-month follow-up. Combined condition participants showed greater reduction in depressed mood, improved hope and optimism after 4-week as well as during 3-month follow-up than the other conditions. Results are discussed in terms of additive or synergistic relation between transcranial direct current stimulation and positive psychology treatment.