Beyond Clozapine Failure: Precision Approach and Palliative Psychiatry in Ultra-Treatment-Resistant Schizophrenia

Clozapine is the only evidence-based treatment for treatment-resistant schizophrenia (TRS); however, up to 70% of patients have an inadequate response, leading to clozapine-resistant schizophrenia (CRS) and, in its most severe form, ultra-treatment-resistant schizophrenia (UTRS). Because evidence-based treatment algorithms after clozapine failure remain limited, management requires an individualized, multimodal approach. We present a UTRS complex case alongside a scoping review conducted according to the PRISMA-ScR framework to summarize the current evidence on the diagnosis, neurobiology, and treatment of CRS and UTRS. A 24-year-old man with schizophrenia required 11 months of psychiatric hospitalization due to persistent psychosis, severe aggression, disorganized thinking, prominent negative symptoms, and profound functional impairment. Extensive investigations, including neuroimaging, cerebrospinal fluid analysis, metabolic studies, and genetic testing, ruled out alternative diagnoses. Despite sequential treatment with multiple antipsychotics, optimization of long-acting injectable therapy, clozapine, pharmacological augmentation, two courses of electroconvulsive therapy (ECT), and intensive multidisciplinary rehabilitation, the patient continued to exhibit severe positive, negative, and cognitive symptoms and functional impairment, meeting the criteria for UTRS. This review emphasizes the importance of excluding pseudoresistance by confirming adherence, assessing clozapine exposure when therapeutic drug monitoring is available, and conducting diagnostic reassessment before establishing a diagnosis of CRS or UTRS. Among available interventions, ECT remains the strongest evidence-based augmentation strategy following clozapine failure, while pharmacological augmentation and other neuromodulatory techniques are supported by low-certainty evidence. These findings underscore the need for individualized multimodal management that integrates pharmacological, biological, and psychosocial interventions, and support consideration of precision psychiatry and palliative psychiatry principles as potential future frameworks when evidence-based therapeutic options have been exhausted.