As a prerequisite for treatment-resistant depressive episodes, it is necessary to understand the specific symptoms to be treated, what is severe, how long have the symptoms been continuing since then, and how much change has occurred with the medicine to be taken in the future. In order to quantify the severity and course of each symptom, it is useful to evaluate with HAM-D, MADRS, or a simple self-describing depressive symptom scale.
 Although drugs are already administered in the case of treatment-resistance, it is necessary to evaluate the benefits and harm caused by taking the medicine and make sure that the benefits exceed the harm. In cases where multiple drugs have already been used, those that were considered as depressive symptoms, especially motivation lowering, fatigue, and lack of thinking or rationale, are likely side effects, and dose reduction or discontinuation of drugs may improve these symptoms.
 In treatment-resistant depression, the tolerability of the antidepressant currently in use has been confirmed, and if a dose increase is possible, increase first. If symptoms do not improve, it is common to decide with patients the next step such as. 1. switching to antidepressant drugs, 2. combination of antidepressants, or 3. augmentation of drugs other than antidepressants.
 Furthermore, it is important to distinguish depressive episodes of bipolar disorder. In our case, it was necessary to change the main drug from an antidepressant to a mood stabilizer.
 In this review, I will outline how to use the above-mentioned treatments, and which medications were used and at what dosages, to report their risks and benefits.
 <Authorʼs abstract>