Informed consent is a requirement for medical research. Obtaining consent can be complex in patients with severe psychiatric disorders, often leading to their exclusion from study participation. Here, we discuss a case involving a patient with clozapine-resistant schizophrenia, highlighting the different perspectives of caregivers and physician-researchers, with an emphasis on decision-making capacity. The case illustrates the complexity of informed consent in this population, including the challenges in assessing decision-making capacity, ethical dilemmas, and potential improvements.<br />We conclude that improving existing standardized assessment tools, promoting inclusive approaches to research participation, and supporting patient representation in decision-making processes can contribute to the quality and integrity of medical research involving individuals with the most severe forms of psychiatric disorders.