Challenges of Treatment-Resistant Bipolar Depression in the Elderly: A Case Study of Successful Modafinil Augmentation

Treatment-resistant bipolar depression (TRBD) poses a significant challenge, especially in older adults, where comorbidities and medication tolerability limit therapeutic options. Modafinil, a wakefulness-promoting agent, has shown promise as an adjunctive treatment in mood disorders. We report the case of a 74-year-old man with long-standing bipolar disorder and multiple comorbidities, including chronic kidney disease (CKD) and cerebellar ataxia, who presented with persistent depressive symptoms despite multiple pharmacological trials. Conventional treatments, including lithium, antipsychotics, and antidepressants, were either ineffective or poorly tolerated. Modafinil was introduced as an augmentative strategy, starting at 100 mg daily and titrated to 200 mg. Over 16 weeks, the patient demonstrated marked improvement in mood, motivation, and wakefulness, with his Montgomery-Åsberg Depression Rating Scale (MADRS) score reduced by 23 points (70%) from 29 to 6. No adverse effects or mood destabilization were observed. This case highlights the potential utility of modafinil in TRBD, particularly in elderly patients with limited pharmacological options. Its broad neurochemical activity and tolerability profile make it a candidate for augmentation in selected cases. While caution is warranted due to potential risks, this report supports further exploration of modafinil in adult populations with TRBD. Modafinil may be a safe and effective adjunct in treatment-resistant bipolar depression, especially when conventional therapies are contraindicated. Its use may extend beyond elderly populations to adults with similar clinical challenges.