A biomarker is a characteristic that is objectively measured and evaluated as an indicator of normal biological processes, pathogenic processes, or pharmacological responses to a therapeutic intervention (
1). Researchers hope that identifying a biological or physiological marker for a psychiatric disorder, rather than relying on behavioral symptoms and signs (as does the current
Diagnostic and Statistical Manual of Mental Disorders), will provide a more precise means of diagnosis and deepen their understanding of etiology and treatment (
2). For example, psychiatric biomarkers could be used to predict the risk for developing a particular disorder.
Biomarkers are typically used as a means of estimating the probability that a disorder is present or will develop. The biomarker is not the cause of the disorder. Algorithms that bundle risk factors might be powerful predictors of psychopathology, but they still represent groupwide statistical probabilities. For a specific individual, the predictive value of the biomarker is less accurate (
2,
4,
5). This leads to social and ethical dilemmas. For example, risk profiling for psychiatric disorders among children could lead to increased stigma toward the child identified as at risk and might adversely affect his or her sense of self and life trajectory—an effect termed “risk identity” (
2, p. 204). Society might alter education, law, and policy to address the “risk” and “potential” psychopathology—in positive or in damaging ways.
Clinical Vignette
Ms. Jackson walked into the office with her 13-year-old son, Mark. She handed Dr. Fuentes an envelope as she shook the doctor’s hand in greeting. Ms. Jackson smiled tensely. Mark slouched in behind her, wearing an emotional mask of practiced bored indifference. Dr. Fuentes guessed they had fought and that Mark was not here of his own accord.
They sat down, and introductions were made. Dr. Fuentes explained that an initial evaluation with an adolescent typically includes an introduction and clarification of the reason for the consultation together. She added that she wanted to meet with Mark and his mother separately to get a history and to have a chance to understand the issues from each person’s perspective.
“So,” Dr. Fuentes proceeded, “what brings you to see me, Mark?”
“My mom,” Mark answered wryly.
“Yes. Shall I assume you didn’t want to come?” Dr. Fuentes inquired curiously.
“Wow, you can read minds. Amazing,” Mark replied sarcastically.
Ms. Jackson burst into the conversation. “Mark has an attitude. He never listens. And I found him smoking pot the other day. At 13! As you can see, he is rude. Well, I thought maybe it was just adolescence, you know. He is my oldest, so I didn’t really know. So I got him tested to see if he is a sociopath.”
Dr. Fuentes looked quizzical. “Which test is that?” she inquired.
“You know. The blood test. It is an add-on for GenieMe, the genetic testing that tells you about your ancestors and possible genetic diseases. He has the sociopath gene,” Ms. Jackson reported, as tears welled up in her eyes. “His dad’s in jail—they say he’s a sociopath, so I had Mark tested. I don’t know what to do,” Ms. Jackson said, tears beginning to spill over and run down her face as she reached for a tissue.
“Mom,” Mark interrupted. “I don’t even know why you made me get that stupid test. I told you. I do what I want, and no oxymoron gene, or whatever it was, makes me do these things.”
Dr. Fuentes nodded. “Ms. Jackson. Mark. I am not exactly sure which test you had—probably for the monoamine oxidase A gene. One thing I do know is that this test—called a biomarker—is only one of many components of behavior and personality. It seems very scientific—a lab test and gene. But people are much more complex than that.”
Dr. Fuentes thought further. “Let me draw a picture of how I think about the gene tests. Let’s say this is Mark,” she said, starting a simple drawing. “Don’t you think it looks like you?” Dr. Fuentes remarked playfully. “So, this half on the right is the environment and all of the effects of experience on your behavior. On the left are genetic influences. Genes control how we look, our temperament—how easygoing or shy or bold we are. So, let’s call this little foot part the biomarker. Maybe it makes a difference, maybe not. It depends on a lot of things, including experience. But there’s a whole lot of other area that isn’t the biomarker. That can make the most difference. So, that’s the part that can be the fun, handsome, sarcastic, and snarky teenager of today—that can grow up to be a fun, handsome, hopefully not quite so oppositional young man.”
Dr. Fuentes looked up from the drawing. “Don’t you think I should have been an artist? Looks sort of like a Picasso, don’t you think?”
For the first time, Mark showed a hint of a smile, before looking down to reaffix his bored and uninterested façade.
His mother sighed. “Okay, so maybe he won’t be a sociopath?”
“He smiled at my joke. He can’t be all bad,” Dr. Fuentes said playfully again.
Mark and his mother both smiled this time—and even at each other.
Communication About Biomarkers: From EELS to Understanding
Biomarkers are becoming commercialized, such as genetic-screening (e.g., 23andMe) and brain-scanning services. Individuals may gain information about their risk profile for numerous diseases and disorders, as well as information on personality and behavioral types (
2). This information may be helpful, and patients have the right to access information provided by these products. However, this genetic testing raises critical questions of how individuals who might test positive for disease risk view and understand the genetic information that they receive (
8).
Studies suggest that individuals at risk for disorders for which definitive tests exist, such as Huntington’s disease, frequently misunderstand the genetic mechanisms, risks, and tests, even after genetic counseling and explanation (
9). The issue of genetic risk taps into a highly subjective personalizing process, which may distort understanding of the facts presented (
10). Identifying a risk biomarker for a psychiatric disorder also taps into the affect-laden personalizing process. Biomarkers, which are perceived as objective and precise, might have greater persuasive power than is warranted by their predictive power. The patient or his or her parents might hear results of biomarker testing as a diagnosis, a predictor, although current biomarkers do not have that degree of accuracy or specificity (
5).
For example, several studies have suggested that a variant of the monoamine oxidase A gene may be associated with risk of antisocial behavior, but only when there is a history of adversity in early childhood (
11,
12). Identifying a child with this risk biomarker might change how others treat the child and lead to a “self-fulfilling prophesy” of behavior that accommodates expectations. Thus, communication of biomarker results must take into account the affective impact, as well as the cognitive understanding, of how the results might affect the patient (
13,
14).
Communicating and explaining biomarker-risk results requires skill, engagement, and ongoing open discussion about the complexity and multifactorial nature of health and psychopathology. Patients who feel cared about and understood are able to use that empathic engagement to regulate emotions and to digest the information discussed. Epstein and Street (
15) have identified a framework for patient-centered communication that includes the following functions: fostering the therapeutic relationship, exchanging information (gathering and providing information), making decisions, enabling disease- and treatment-related behavior, responding to emotions, and managing uncertainty.
In the specific case of communicating results of biomarker testing, these steps require multiple skills: the skill of engaging the patient; of breaking bad news; of explaining complexity and ambiguity regarding the import of biomarker results related to psychiatric disorders; of attending to issues of culture and stigma related to familial disorders or psychosocial risks; of maintaining empathic attunement; and of considering EELS that might be relevant. Ethical issues connect to a potential increase in stigma—particularly as it relates to building on biases related to ethnic or racial minority groups being at risk for psychiatric, substance, or behavioral disorders. Economic issues and psychosocial adversity interact with mental health in multiple dimensions—stressed individuals are at higher risk for psychopathology, and economic issues might affect the access and affordability of genetic testing and evidence-based treatments for individuals at risk for a disorder. Legal issues might relate to who owns the biomarker information, whether it can be accessed by insurance companies and might lead to an increase in premiums or loss of insurance for a “pre-existing illness,” and how to ensure informed consent.
As always, “First, do no harm” is an ethical precept for all testing and interventions. Biomarkers for psychiatric disorders are most useful when identified prior to the onset of the disorder and when evidence-based early interventions or treatments are anticipated to improve prognosis. The social impact for an individual with a risk biomarker, as well as for educational and other institutions, needs to be considered, and advocacy might be indicated to ensure access to appropriate services and social supports (
6).
One area of biomarker testing that is becoming increasingly common is the use of pharmacogenetic testing to inform prescribing. Pharmacogenetics uses a person’s genetic data to help determine how that individual will respond to a specific medication. Although these tests can be expensive and there is some disagreement in the field about how useful they are and how often they should be ordered, several companies test an individual’s genetic profile on pharmacokinetic and pharmacodynamic measures. In psychiatry, pharmacogenetic testing is usually applied to antidepressants, with the aim of improving depression remission rates and reducing adverse effects by identifying genetic markers that could be used as clinical tools for tailoring treatment (
16,
17).
The following are communication tips for psychiatrists to use when discussing biomarkers related to psychiatric disorders or treatment:
1.
Stay up to date.
A.
Genetic testing comes in many forms—many of them proprietary. Patients might present with results from one of a number of genetic-testing companies (AncestryDNA, 23andMe, and National Geographic's Geno 2.0 test, to name a few). Understanding how to read and explain the results to your patients might be helpful.
B.
Psychiatric biomarkers for antisocial behavior, schizophrenia, mood disorders, autism, and others are beginning to be reported. Most of these tests are used for research and are not clinically indicated at this time. In the next few years, the use of these tests may increase, and patients may ask about them.
C.
The Flockhart Table (
18) of clinically relevant P450 drug interactions is easily accessed and kept up to date by Indiana University. If you access pharmacogenetic testing for your patient, you can use the Flockhart Table to determine which medications are affected by which P450 enzymes.
D.
If a patient presents results of pharmacogenetic or other testing, consider how best to use these data in treatment decisions. Be sure you know how to interpret the data. Cost, U.S. Food and Drug Administration approval, evidence base, and other considerations must also be taken into account.
2.
Engage.
A.
Consider the meaning, in addition to the results, of any biomarker request for testing or test results. Help the patient explore and understand the affect and inquire about the personalizing process—how biomarker results are affecting his or her sense of self, or “risk identity.”
B.
As with the breaking of any bad news, skills develop with time. If a patient is identified with a genetic syndrome (e.g., XXY), a known biomarker, or even a risk factor for a medical disease, consider how you would react and how you think your patient will react. Should a loved one be present for the conversation?
C.
Beware of jargon—physicians tend to use more medicalized terms when discussing bad news or emotionally charged issues. Keep the communication simple and to the point, and be sure to describe risk as well as reasons for optimism. Give plenty of time for questions and discussion. Consider having the patient “teach back” or review with you what was just discussed in his or her own words. That will help identify any misperceptions.
D.
Consider cultural or lifestyle implications of biomarker results. Remain sensitive and humble to learning how your patient understands these results.
E.
Demystify and clarify—give information about limits of the findings. As in the vignette above, individuals (perhaps even the doctor) might overvalue biological marker results. You will need to reiterate and revisit this complexity and the limitations of test results multiple times to help the patient digest the information.
3.
Practice EELS.
A.
Ethical issues: Are there potential negatives for the patient regarding accessing biomarker or genetic testing? Is there potential for discrimination on the basis of these results? How will the results affect the patient’s sense of self and integrity? How will they affect how others see him or her?
B.
Economic issues: Many tests are expensive, and patients, even if they have good insurance, might have to foot the bill. Consider risks and benefits, as well as the issues of access and affordability of interventions if a risk factor is identified.
C.
Legal issues: When you discuss biomarker testing with patients, it is important to consider issues of privacy, the potential for results to be used by insurance companies or others to increase rates or deny insurance, and questions related to informed consent (particularly by minors, as in the vignette above).
D.
Social consequences: How will biomarker results help or harm a patient’s social sense of self and others’ perception of him or her? In the vignette, the adolescent’s mother perceived the biomarker to be proof that her son would turn out to be a sociopath “like his father.” In addition to information, the emotional impact of the results needs to be addressed with the patient and significant others.
4.
Discuss treatment implications of the biomarker, and make modifications, as appropriate.
A.
If you are using pharmacogenetic testing to help choose an antidepressant, discuss the issues related to the antidepressant (risks and benefits) as well as the limits of pharmacogenetic testing information.
B.
Many patients will assume that “a match” or a “green dot” by the pharmacogenetic results of a medication means that it is sure to work for them. A simple explanation of what it does tell (pharmacokinetics or dynamics) is helpful.