Mental Disorders and Decision Making

How do we know who can decide?

This has been a busy week for bioethics-related news, so, before the article, here are a few news stories:

• Why More Quebec Family Doctors are Leaving the Public Health System – The Globe and Mail

• The Hidden Harms of CPR – The New Yorker

• Vancouver Hospital Defends Suggesting MAID to Suicidal Patient as Risk Assessment Tool – The Globe and Mail. The hospital said “the topic of MAID was brought up to gauge Ms. Mentler’s risk of suicidality,” which doesn’t strike me as a good excuse.

Photo by Jens Lelie

Brandon Beasley has written an excellent reply to my post “The Limits of Psychiatry.” In that article, I argue that knowledge gaps in the diagnosis and treatment of mental illness are not good reasons to prohibit assisted dying for people with a mental disorder. Brandon’s response is that the nature of mental illness makes assisted death inappropriate much (all?) of the time.

There are a few issues about which Brandon and I disagree. Here, I’m going to focus on decision-making capacity.

Capacity

At the end of my article, I make a wildly misleading claim, which I’ve italicized here:

When it comes to making important medical decisions, we want patients to be as informed as possible. This includes knowing about uncertainty. We make decisions under uncertainty all the time: the drug might cause these side effects, the cancer might go into remission, you might be able to walk again. What we should do with this information is, as always, something that should be left up to the patient.

The natural reading of ‘as always’ is, uh, always, so one could reasonably conclude that I think all people should be left to make their own decisions. But that would be a terrible view, and, despite my poor wording to the contrary, it’s not what I think. People who have delirium, psychosis, advanced dementia, are in a coma, or are three years old shouldn’t (or can’t) make important medical decisions. 

What I really meant was that people who can make their own decisions should be able to decide for themselves, but not everyone can. Still, that blunder aside, Brandon and I seem to have a genuine disagreement about the possibility of people with mental illness making informed decisions about MAID.

To have decision-making capacity means being capable of understanding the risks and benefits of a proposed medical intervention and its alternatives. Insight is key. In my experience, if you ask a three-year-old a question about a complex topic, which I do all the time, she’ll never say “I don’t know” or “I need more information”. Yesterday, I asked one “Do you think Brexit was a good idea?” and she immediately responded “Yes!”. I asked her why, and she said, with confidence while looking at the shaving brush she was holding, “this brush has brown fizzers.” She can make decisions, but on some matters, she’s incapable of understanding the relevant information even when I provide her with it, so her choice isn’t meaningful. She lacks decision-making capacity for that decision.

Capacity is a hugely important concept in medicine. If you have capacity, you can consent to or refuse any intervention that’s offered to you. If you lack capacity, someone else should decide for you. Respecting autonomy for those who have it is essential, but so is protecting vulnerable people who are incapable. It would be a serious violation of someone’s rights to override his decision if he was capable of making it himself; it would also be bad to rely on a person’s decisions when she is incapable of making valid, informed ones.

The problem is that capacity isn’t something out in the world the way cancer or Covid-19 or chronic obstructive pulmonary disease are. We know there is such a thing as Covid-19 caused by the virus SARS-CoV-2, and we can make tests to identify it and then validate those tests by seeing how often the test gives the wrong answer.

Capacity isn’t like this. It’s a cluster of abilities, the most commonly accepted ones being understanding, appreciation, reasoning, and expression of a choice. But each of these comes in degrees, so there’s no clear threshold that distinguishes having capacity from lacking it. Some people clearly have it, others clearly don’t, and hard cases exist between. Further, even if we could precisely measure each ability, reasonable people could disagree over where to set the line.

Clinically, there are two approaches. In many places, any physician can deem a patient incapable based on clinical judgment. This is very much a “I know it when I see it” or vibes approach. As Kahneman, Sibony, and Sunstein discuss in Noise, any time people rely on professional judgment, there’s going to be variability. So it is with capacity. In one study, patients admitted to a hospital were evaluated for capacity by a psychiatrist, then evaluated by other experienced clinicians. All used clinical judgment and they agreed a bit over half the time about a patient’s capacity. 

In the politely titled paper “Are clinicians ever biased in their judgments of the capacity of older adult’s to make medical decisions?”, researchers gave six clinicians (psychiatrists, psychologists, and geriatricians) the results of decision-making interviews from twelve patients. Eight patients had a diagnosis of mild dementia and four had schizophrenia. There was a lot of noise: one clinician said that 42 percent of the patients had capacity, another found that 83 percent of patients did.

Noise decreases when clinicians receive specific training on capacity—which, again, many don’t, even though they can all make capacity decisions—and when they use structured instruments. These instruments, such as the MacArthur Competence Assessment Tool for Treatment (MacCAT-T), which is often considered the gold standard, have standardized questions to measure the traits that make up capacity. It takes about twenty minutes and begins with the clinician explaining the patient’s disorder then a recommended treatment, and it has questions for the clinician to ask the patient. The MacCAT-T produces a score, but the test itself doesn’t define the threshold for capacity. That’s still left up to the clinician. Noise is higher for some disorders than others, but there’s much more consistency than using the judgment/vibes approach. For some background on capacity and the assessment tools, see here.

Mental Disorders and Assisted Dying

In his comment, Brandon says the following:

To think that most people suffering from mental illnesses/disorders are capable of making appropriate judgements according to their all-things-considered values is just false. Which means that it would be wrong to take those judgements at face value and pursue medical options on their basis.

My misleading blunder notwithstanding, I can clarify that my actual view is just that some people with a mental disorder are capable of making appropriate judgments according to their all-things-considered values. There are lots of types of mental illness that present in many different ways and to different degrees. There are certainly people who lack capacity due to their mental disorder, and it’s appropriate to assign them a substitute decision maker instead of letting them make decisions they can’t understand. People who lack the capacity to decide about MAID shouldn’t be allowed to consent to MAID.

The question is whether the presence of a mental disorder guarantees incapacity. There have been studies on this, and the answer is no. Depression is especially relevant, since that’s the one people often worry about for MAID.

Here’s a systematic review of depression and capacity. There’s broad agreement that, when depression affects capacity, it tends to affect the person’s ability to appreciate the consequences of his decisions. Using the MacCAT-T, the gold-standard tool, a study on people hospitalized with major depression found that, of the ninety-two patients studied, twenty-two of them (23.9 percent) had impairment in one of the capacity traits.

Another study compared capacity results between the MacCAT-T and clinician judgment in patients with dementia, depression, or schizophrenia. The standardized approach resulted in far more patients being deemed impaired than by clinical judgment: 67.7 v. 48.4 percent of patients with dementia, 20 v. 2.9 percent of patients with depression, and 53.5 v. 18.4 percent of patients with schizophrenia. This one used the MacCAT-T to assess capacity among inpatients at a psychiatric hospital. It found that 31 percent of the patients with depression lacked capacity. 

Another systematic review looked at capacity in psychiatric inpatients. Here, as usual, there’s lots of noise. “The prevalence of decision-making capacity among involuntary patients ranged from 7.7 percent to 42 percent, and among voluntary patients ranged from 29 percent to 97.9 percent.” Further, two of the studies found that clinical judgment and MacCAT-T scores were positively correlated, but two other studies found no correlation.

None of these studies looked at capacity for assisted dying, and, as one of the reviews puts it, the literature on capacity and depression is a “surprisingly small literature on topics of considerable ethical, clinical and policy importance.” Still, even among people admitted to hospital because of severe depression, none found incapacity to be universal or, in some of the studies, even above fifty percent.

The literature on capacity assessments for assisted dying is smaller. A study of one hundred euthanasia requests in Belgium, where assisted death is legal for people with mental disorder as the sole medical condition, found that 48 percent of requests were granted. Belgium requires “unbearable and untreatable psychological suffering”. The study notes that all the people who made the requests were found to have capacity. In a study from the Netherlands, physicians disagreed on patient capacity in 12 percent of cases. 

Alec Yarascavitch and, independently, Louis Charland, Trudo Lemmens, and Kyoko Wada have raised concerns about using only clinical judgment to assess capacity for people with mental illness requesting MAID. Given the subjectivity of clinical judgment, I’m sympathetic to this concern for all contexts, not just for MAID.

My view is that, given the variety of mental disorders and their severity, the best approach is to rigorously assess each person’s capacity instead of making everyone with a mental disorder ineligible for MAID. This is already the case in Canada, where having a mental illness doesn’t disqualify a person from MAID, though it can if the mental illness interferes with capacity. Next year, Canada will begin allowing MAID based solely on mental illness, so long as the person meets all the criteria, including having capacity.

Udo Schuklenk and Suzanne van de Vathorst take the right approach in their paper “Treatment-Resistant Major Depressive Disorder and Assisted Dying.” They recommend the following conditions, which should apply regardless of the nature of one’s condition:

• The patient is competent to evaluate her current situation.

• The patient is competent to evaluate her future prospects based on the scientific evidence available at the point in time when she requests assistance in dying.

• The patient’s decision is voluntary and informed.

• The patient’s quality of life is such that she doesn’t consider it worth living, and the likelihood of improvement is exceedingly small or non-existent.

• The patient repeats her request over a reasonable period of time.

Some people with a mental disorder will meet these criteria and others won’t, so each patient who makes a request must be assessed individually. Some, like Lisa Pauli, who has been treated for anorexia for decades without improvement, are unlikely to improve. The same will be true of some people with treatment-resistant depression.

In my article on psychiatry, I say that “The hard thing about psychiatry is that it’s about the brain. This is just bad luck for psychiatrists. They’d have a much easier time if their field concerned a simpler part of the body.” Getting a capacity assessment wrong in either direction is bad, so the best approach is to make the process thorough and continue to improve it. Banning MAID because we can’t be sure about capacity means that some people will continue to suffer intolerably, which isn’t good either. Psychiatry has limits, but MAID is still justified in some cases.