The concept of informed consent is a cornerstone of ethical practice. It ensures that patients have the autonomy to make decisions about their treatment, while also protecting them from potential harm. However, a dilemma rises regarding decisions on whether or not a patient has mental capacity to provide voluntary informed consent. The instance of this dilemma is most prominent in the field of Psychiatry, more specifically, among patients with Alzheimer’s. Alzheimer’s is a progressive neurodegenerative condition characterized by cognitive decline affecting memory, reasoning, and decision-making abilities. As dementia advances, individuals may face challenges in understanding information, appreciating the consequences of decisions, and communicating preferences. This complicates the process of obtaining valid informed consent for medical interventions.

Mental capacity is not a black-and-white issue. It exists on a spectrum, which is a core reason why it is so challenging to determine whether or not an individual possesses the requisite capacity. According to the Alzheimer’s Society, to have “mental capacity,” a person must be able to keep the information in their mind long enough to make the decision and weigh up the information that is available to make the decision. This involves grasping the nature, purpose, and potential consequences of the decision at hand. For individuals with dementia, this comprehension may be influenced by the progressive cognitive decline associated with the condition. Currently, there are limited methods available to definitively determine whether the patient has undergone a significant cognitive decline. The most notable method involves the utilization of standardized testing tools for assessing mental capacity known as the Montreal Cognitive Assessment (MoCA).

MoCA assesses cognitive domains relating to attention and concentration, executive functions, memory, and conceptual thinking in the format of a test in which the higher the participant scores, the less likely they are to have dementia. While this method sounds reliable on paper, it turns out to have a major limitation, which has to do with the cut-off score used by practitioners. According to a 2021 review, a cut-off score that is most often used (26 out of 30) results in a significant number of incorrect results, with over 40% of people without dementia being mistakenly identified as having dementia. This proves how this method is not very reliable, as paper tests are not able to capture the full spectrum of a patient’s decision-making abilities, leaving room for potential mistakes.

If an individual is said to not have the mental capacity to provide informed consent, healthcare professionals need to rely on substituted judgment. Substituted judgment refers to the process of making medical decisions on behalf of an individual who is incapacitated by consulting a surrogate decision-maker. The surrogate, often a family member or a close friend, is entrusted with the responsibility of making decisions that align with the incapacitated individual’s values, beliefs, and previously expressed preferences. Despite its ethical foundation, implementing substituted judgment can be challenging. Surrogates may struggle with the emotional burden of making decisions on behalf of a loved one, and the available information about the patient’s preferences may be incomplete and even ambiguous. Additionally, family dynamics and potential conflicts among surrogate decision-makers can complicate the decision-making process. Substituted judgment relies on the surrogate’s ability to accurately predict what the patient would have wanted in a given situation. Predicting someone else’s preferences, especially in complex medical scenarios, is inherently challenging and may lead to decisions that do not fully align with the patient’s actual wishes.

The decision to assess a patient’s mental capacity for informed consent is one of the most ethically challenging aspects of medical practice, and there is still a long way to go until we find the optimal way to do it. Striking a balance between respecting autonomy and ensuring patients’ well-being is a complex task that requires consideration of multiple perspectives and opinions. Healthcare professionals must be equipped with the knowledge and tools necessary to assess mental capacity accurately, ensuring that informed consent remains a meaningful and protective process for patients. Continuous education and raising awareness of this issue are essential in order to come up with a better solution for assessing mental capacity in patients with dementia.