Ethical and Procedural Pathways to End-of-Life Care for Patients with Serious Mental Illness and Decisional Incapacity: A Systematic Review

Every person carries a set of values and preferences that guide how they want to live, and ideally, how they want to die. When a person becomes too ill to speak for themselves, society relies on a system of surrogates and legal documents to honor those wishes. This system works relatively smoothly for people with terminal physical diseases like cancer or heart failure, where the path to the end of life is often clear and medically defined. However, a different and more complicated picture emerges for the millions of adults living with serious mental illness. These conditions, which include disorders like schizophrenia and bipolar disorder, can severely disrupt a person's ability to make decisions, sometimes leaving them unable to understand their own medical situation or communicate what they want.

The challenge becomes acute when these patients face the end of their lives. If a person with a serious mental illness also develops a terminal physical disease, doctors must decide whether to continue aggressive treatments or shift to comfort-focused care. But the presence of the mental illness often clouds the process. Clinicians may struggle to determine if a patient's refusal of treatment is a genuine expression of their values or a symptom of their illness. They must also navigate a confusing landscape where the concept of a "terminal psychiatric illness"—the idea that a mental disorder itself can be the final, untreatable cause of death—is debated but rarely defined. Without clear rules, patients with serious mental illness often face delays in receiving the compassionate care they need, or they may be kept alive against their will because no one is sure they truly have the right to say no.

A team of researchers set out to map this difficult terrain by examining how American literature discusses these issues. They conducted a systematic review, a methodical process of gathering and analyzing hundreds of written records to find patterns in how experts think about end-of-life care for people with serious mental illness who cannot make their own decisions. The researchers searched through medical and psychological databases, looking for English-language studies and reports from the United States that touched on three specific areas: how end-of-life care is handled when a patient has a terminal physical disease alongside a mental one, the controversial idea of a terminal psychiatric illness, and the complex process of assessing whether a patient has the mental capacity to make decisions. They excluded discussions about assisted suicide or euthanasia, focusing instead on the standard pathways to hospice, palliative care, and the refusal of life-prolonging treatments.

After sifting through more than three thousand records, the team narrowed their focus to 154 documents that provided the most relevant insights. These sources ranged from scientific studies and legal analyses to policy statements and commentaries. The researchers found that the most reliable and consistent path to end-of-life care for these patients occurs when a terminal physical illness is present. When a patient has a clear medical condition like advanced cancer or organ failure, the system for hospice and palliative care is well-established. In these cases, the mental illness is often treated as a barrier that must be managed, but the physical diagnosis provides the necessary gateway to access comfort care. The presence of a surrogate decision-maker, such as a family member or legal guardian, was the single most important factor in helping these patients receive care that matched their goals.

The picture becomes much murkier when the mental illness itself is considered the terminal condition. The researchers discovered that there is no agreed-upon definition for what makes a psychiatric illness "terminal." While some experts argue that severe, persistent mental illness that does not respond to treatment should be treated with the same palliative approach as a terminal physical disease, the literature showed no consensus on how to identify such cases. The documents reviewed offered a wide variety of criteria, including the futility of treatment, the severity of the symptoms, or the ethical burden of forcing treatment on an unwilling patient. However, no single factor appeared in more than a quarter of the records, and the majority of the documents did not define the criteria at all. This lack of clarity means that a patient whose life is limited by a mental disorder alone often cannot access the same end-of-life resources as someone with a terminal physical disease.

Central to all these decisions is the assessment of capacity, which is the evaluation of a person's ability to understand information, appreciate their situation, reason through options, and communicate a choice. The review highlighted that this assessment acts as a critical gatekeeper. If a patient is deemed to have the capacity to refuse treatment, they can choose to stop life-prolonging measures or decline hospitalization. If they are found to lack capacity, the decision falls to a surrogate or is made based on what is in the patient's best interest. The researchers noted that this process is fraught with inconsistency. Different doctors may apply different standards, and a patient's capacity can fluctuate, changing from day to day or even hour to hour. There is also a risk that a doctor's own values or biases might influence whether they believe a patient is capable of making a decision, potentially leading to situations where a patient's wishes are overridden because the doctor disagrees with the choice.

The study also examined the role of advance directives, which are legal documents where a person states their medical wishes in advance. While psychiatric advance directives exist to help people with mental illness plan for future crises, the literature suggests they are difficult to use in end-of-life situations. Many documents noted that these directives are often not designed for medical decisions, or that they are hard to implement when a patient is in a crisis. Furthermore, there are concerns about whether a person truly had the capacity to sign the directive when they created it, or if a surrogate can legally override it. The researchers found that while these tools are intended to protect patient autonomy, they often fail to provide the clear guidance needed when a patient is at the end of their life.

Ultimately, the review paints a picture of a system that works well for patients with terminal physical illnesses but leaves those with serious mental illness in a state of uncertainty. Access to goal-concordant care—care that aligns with a patient's values and wishes—is most consistent when a terminal medical diagnosis is present and when a surrogate is available to speak for the patient. The concept of a terminal psychiatric illness remains a contested idea without clear rules, and the process of determining capacity is often inconsistent and vulnerable to bias. The researchers concluded that without clearer standards for defining when a mental illness is terminal and more consistent methods for assessing capacity, patients with serious mental illness will continue to face barriers to receiving the dignified, goal-aligned care they deserve at the end of their lives. The path forward requires developing better definitions and procedures to ensure that these vulnerable patients are not left behind by a system that struggles to understand their unique needs.