Chapter 1. Introduction to the Diagnostic Interview

When you conduct a diagnostic interview, you generate a diagnosis, one of Cohen’s “provisional formulae” for clinical actions. The diagnoses generated by a DSM-5-TR interview are called disorders, rather than diseases or illnesses. All three terms describe impairments of normal functioning, but the DSM system uses disorders to acknowledge the complex interplay of biological, social, cultural, and psychological factors involved in mental distress.

Physicians usually think in terms of diseases, which can be described as pathological abnormalities in the structure and function of body organs and systems. Patients usually present with illnesses, which are their experiences of pathological abnormalities or being sick. From a distance, diseases and illnesses may seem like the same experience viewed from the different perspectives of patient and physician. However, consider a condition such as hypertension, which is often identified incidentally, without any associated clinical findings. To the diagnosing physician, hypertension is a chronic disease of the vasculature that increases the risk of stroke and a heart attack, but patients often do not recognize themselves as being sick or as having an illness. Conversely, a patient may present as feeling quite ill and describe themselves as homesick, but physicians do not recognize this as a disease. Diseases and illnesses are often divergent experiences, rather than merely different perspectives, as anthropologists have repeatedly documented (Oberlander 2019).

An anthropologist can also tell you that illness experiences are culturally constructed: different conditions will be recognized as diseases or illnesses in different places and times. However, to be recognized as suffering from a disease or an illness, an individual requires some kind of diagnosis, often a diagnosis from a physician.

When a particular culture recognizes a person as suffering from a condition that alters one’s place in the community, the person enters what American sociologist Talcott Parsons (1951) famously called the “sick role.” Parsons observed that a person recognized as sick is exempted from normal social roles. Sick people do not have to perform their usual roles, but the degree of exemption from their social roles is relative to the nature and severity of their illness, as well as to their ages and cultural roles. To use contemporary examples, the child gets to stay home from school for mild fever and diarrhea, but the adult with back pain will receive disability only after experiencing years of refractory pain.

As part of the sick role, the sick person is usually not held responsible for their illness because sickness is believed to be beyond human control. So when a physician diagnoses a person with a sickness, the physician legitimizes the person’s illness and admits them to the sick role (Parsons 1951). Admitting a person to a particular culture’s sick role is part of what occurs when you diagnose a person’s distress as a specific condition, and you need to remember that any diagnosis you assign to a person’s distress has this cultural function.

Although all diagnoses have a cultural function, psychiatric diagnoses are especially complicated. Mental disorders result from biological, genetic, environmental, social, and psychological events and processes, and these etiological factors are involved to differing degrees in the development of different psychiatric diagnoses (Kendler 2012). Furthermore, because psychiatric diagnoses describe dysfunction in faculties believed to define one’s personhood, they often constitute a threat to a person’s sense of identity (Rüsch et al. 2005). Finally, the culture of clinicians and of medical facilities both shape the clinical encounter, altering what patients say and display and the outcomes they experience (Fiscella and Sanders 2016; Saini et al. 2017).

To recognize this complexity, the authors of DSM chose the term disorder to describe psychiatric diagnoses. Disorder can be broadly defined as a disturbance in physical or psychological functioning. The term is used elsewhere in medicine to describe genetic disorders and metabolic disorders. However, most diagnoses in medicine are called diseases rather than disorders, and naming psychiatric diagnoses as disorders reinforces a distinction between mental problems, disorders, and physical problems, diseases (Wallace 1994). We can see this when we consider that while a psychiatrist diagnoses a person with a “mental disorder,” an internist does not diagnose a person with a “physical disease.” Instead, an internist tersely diagnoses a person with a “disease,” illustrating how our use of the adjective “mental” before “disorder” implicitly endorses a division between the body and the mind.

The authors of DSM-5-TR reduce this division by naming, whenever possible, the etiology of a mental disorder. They do so, for example, with several neurocognitive disorders (e.g., Lewy body, traumatic brain injury, vascular disease). However, the definition and limits of most categories of disorder remain broad. They range from illicit behaviors to particular pathological processes with well-characterized etiology, genetics, and prevalence. Therefore, the ambiguity about what precisely a disorder is remains.

Perhaps this is apt.

After all, diagnoses are an abstraction of a person’s experiences and bear the marks of the era in which they were constructed and employed. Some diagnoses exist in one era and not another—hypertension, to return to our previous example, was not diagnosed in the 18th century because blood pressure could not consistently be measured. Some diagnoses serve one era’s assumptions and not another’s—as when psychiatric diagnoses were used to pathologize impoverished 19th-century Irish immigrants (Hirota 2017) and 20th-century Black activists (Metzl 2009) as part of racist, classist ideologies. Some diagnoses will be situated within psychiatry in one era and not in another. Some behaviors attendant to a seizure disorder, for example, can be attributed to epilepsy or to psychotic disorders (Sachdev 1998). Diagnoses serve cultural functions.

In this sense, using disorder to describe mental distress draws attention to how mental distress impairs a person’s function, suggests the complex interplay of events that result in mental distress, and implicitly acknowledges the limits of our knowledge about the causes of mental distress. We do not know enough to be more precise. Instead, we can consider the ongoing use of disorder in our diagnostic systems as an opportunity for humility and a spur to further study. In the words of Ken Kendler, one of the most learned contemporary explorers of psychiatric diagnoses, “Tolerance for diversity and humility come with scientific maturity” (Kendler 2014a, p. 937).

The people you meet who have mental distress cannot simply wait for the precision that they and you desire—they deserve the best possible answers you can offer in the present moment. Cultural anthropologist Richard Shweder (2003) famously noted that anything observed from a single point of view is incomplete; incoherent when observed from all points of view at once; and empty if observed from no point of view at all. You have to take a particular point of view, but with the understanding that despite being necessary, the point of view you take is necessarily incomplete. It is far easier to criticize definitions of a mental disorder than it is to construct an accurate, precise, and useful definition.

According to the authors of DSM-5-TR, a mental disorder is “a syndrome characterized by clinically significant disturbance in an individual’s cognition, emotion regulation, or behavior that reflects a dysfunction in the psychological, biological, or developmental processes underlying mental functioning.” They distinguish a mental disorder from an “expectable or culturally approved response to a common stressor or loss, such as the death of a loved one.” The authors caution, “Socially deviant behavior (e.g., political, religious, or sexual) and conflicts that are primarily between the individual and society are not mental disorders unless the deviance or conflict results from a dysfunction in the individual.” This definition of a mental disorder, along with the authors’ insistence that a diagnosis “have clinical utility” and “help clinicians to determine prognosis, treatment plans, and potential treatment outcomes for their patients” (American Psychiatric Association 2022), has several important implications for the diagnostic interview (Stein et al. 2010).

First, the definition characterizes a mental disorder as causing a clinically significant disturbance in a number of possible domains. This means that when you interview persons with mental distress, you need to explore the extent to which their distress significantly impairs their cognition, emotions, and behaviors. However, the definition does not characterize what constitutes a “significant” impairment. Without such precision, you need to define impairment with your patient based on how they functioned before the onset of the signs and symptoms with which they are presenting for evaluation. You might do this by asking the person to recall a time before the most recent onset of their distress and to describe the differences between their function at that point and in the present. Ideally, you will also obtain collateral information from people who know the person in multiple situations to help assess their premorbid ability and function. You may also want to use the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0), the disability assessment tool endorsed by the authors of DSM-5-TR (World Health Organization 2010), which is discussed in Chapter 12, “Selected DSM-5-TR Assessment Measures.” Several other validated disability assessments are available, but whichever you use, you need to define dysfunction and impairment, along with their degree, individually for each person you evaluate.

Second, because the definition identifies dysfunction as occurring because of underlying disturbances in “the psychological, biological, or developmental processes underlying mental functioning,” you need to assess all of these processes. The DSM-5-TR criteria offer clear guidance on how to elicit and organize symptoms of psychological processes, but provide less guidance for assessing biological and developmental processes. Because it is your responsibility to consider a person in full, you will need, at the least, to seek an understanding of the person’s medical history and developmental stage. I briefly discuss ways to assess these processes in Chapter 3, “The 30-Minute Diagnostic Interview,” and Chapter 8, “Six Questions to a Differential Diagnosis.”

Third, the definition excludes dysfunction that is in some way expected. This can include responses to events such as the loss of an intimate relationship or employment—that is, events that induce mental distress in many people. The DSM-5-TR definition mentions “culturally approved” responses but does not define what constitutes either a culture or its approval, which further points to your need to assess the relationship between the symptoms you elicit in a diagnostic interview and their context in a person’s life. Therefore, you might ask the person, or their family, friends, partners, and peers, if their response is consistent with the responses of their culture, because you need to explore the cultural context in which the person with mental distress presents.

Fourth, the definition simultaneously excludes dysfunction caused by a disagreement between a person and their broader culture. A person’s thoughts and behaviors may clearly be in conflict with those of their intimates or with their culture. Conflict in and of itself is not evidence of a mental disorder. A person can disagree with the leaders of their country, disengage from their faith community, or dislike their siblings without having a mental disorder. For a diagnostic interview, establishing a person’s cultural expectations and baseline behaviors is important, especially when you are interviewing a person whose age, gender, culture, experience, faith, language, or lifestyle is different from your own—in short, almost everyone you meet. You should ask a person what their distress means rather than make assumptions about its meaning.

Fifth, the definition includes an important caveat: a diagnosis must be clinically useful. This caveat helps further distinguish DSM-5-TR from a birding guide, because even if a person endorses all the symptoms of a particular disorder, if the disorder does not usefully inform that person’s diagnosis, treatment, or prognosis, then the diagnosis is considered inappropriate. This requirement for clinical utility speaks to the pragmatic nature of DSM-5-TR, which is a diagnostic system designed to enable accurate and reliable communication of psychiatric findings, rather than to diagnose disorders simply for the sake of doing so.

In reviewing the definition of a DSM-5-TR mental disorder, it becomes clear that the authors of DSM-5-TR left much undefined. This lack of definition necessitates, as happens so often in psychiatry, the exercise of practical wisdom (Radden and Sadler 2010). In the diagnostic interview, it means applying diagnostic categories to the irreducibly particular person before you. To define a mental disorder for the person before you, you need to seek a thorough understanding of the patient as a person. While a good diagnostic interview produces a diagnosis, it also generates questions you will need to ask as you seek understanding. These questions can relate to diagnosis, treatment, and prognosis.

At the conclusion of any diagnostic interview, you should generate a list of additional information you need for a more actionable diagnosis. This additional information can be as straightforward as collateral information from people who know your patient in other contexts, including reports from past psychiatrists, psychologists, therapists, counselors, primary care physicians, pastors, employers, coworkers, teachers, peers, friends, family, partners, and spouses. At times, you may wish to address particular areas of concern by administering additional diagnostic tests, such as physical or neurological examinations, or neuropsychological or personality tests. Before you administer additional tests, you should understand the strengths and limitations of each test and consider how a positive or a negative test result will change your therapeutic relationship. Finally, it is always useful to seek further understanding of a person’s coping strategies and their understanding of the etiology and treatment of mental distress. People present with their distress, but they are not their distress. So ask after their strengths, their passions—about the activities that constitute their flourishing (VanderWeele 2020).

Although DSM-5-TR is not a treatment manual, the diagnostic interview is a time to consider whether and what treatment is indicated (cf. Hilt and Nussbaum 2016; Wang and Nussbaum 2017). With experience, you can initiate treatment in the interview by incorporating basic therapeutic techniques into your diagnostic interview. Many teachers recommend a classic text, The Psychiatric Interview in Clinical Practice (MacKinnon et al. 2016), to learn how to organize a psychiatric interview for the personality structure of your patient. If you feel presently unable to introduce therapeutic techniques into your diagnostic interview, you should at least begin mentally formulating the case and identifying resources keyed to the person’s particular problems and strengths as you interview them. Ways to do so are discussed in subsequent chapters.

Finally, DSM-5-TR offers nothing in the way of prognosis to help a patient know what to expect of the treatment you recommend. You ought to offer reasonable hope to the person you interview. This hope should be informed by an evidence-based review of the scientific literature, your clinical wisdom, and your understanding of the person’s premorbid functioning and of the available resources, but also by the possibility that the existing resources could be expanded through clinical advocacy. There are, after all, many kinds of clinical actions.

Critics of DSM-5-TR are concerned that it will be used as a psychiatric checklist rather than as a means for a comprehensive examination (see, e.g., McHugh and Slavney 2012). DSM-5-TR certainly can be received and misused that way. You can also employ it as one part of a comprehensive diagnostic interview that both characterizes the distress a person describes and helps in beginning to understand the person experiencing the distress. DSM-5-TR continues to rely on the experiences and symptoms reported by a person, but you can receive this as an implicit acknowledgment of the limits of the available knowledge about mental distress and an invitation to attend closely to each patient. In this fashion, your use of DSM-5-TR reflects your orientation toward the well-being of your patients, as well as your humility and willingness to revise your “provisional formulae” as you gain further insight and seek the ever-more fitting clinical action to which they aspire. In short, you can use a DSM-5-TR diagnosis both as an invitation to understand a person’s mental distress and as the beginning of a conversation, rather than its conclusion, to create provisional formulas for clinical action.