This excerpt — discussing 14 valuable tips to help a clinician in the diagnostic mental health interview — is reprinted here with permission from Essentials of Psychiatric Diagnosis: Responding to the Challenge of DSM-5.

The Relationship Comes First.

An accurate diagnosis comes from a collaborative effort with a patient. It is both the product of that good relationship and one of the best ways of promoting it. The first interview is a challenging moment, risky but potentially magical. Great things can happen if a good relationship is forged and the right diagnosis is made. But if you fail to hit it off well in the first visit, the person may never come back for a second. And the patient doesn’t always make it easy. It is likely that you are meeting him on one of the worst days of his life. People often wait until their suffering is so desperate that it finally outweighs the fear, mistrust, or embarrassment that previously prevented them from seeking help. For you, a new patient may be just the eighth patient you see in a long and hectic workday. For this patient, the encounter is often freighted with expectations that are exaggerated for good or for bad. Every diagnostic evaluation is important for the patient, and it should be for you too. The focus, first and always, should be on the patient’s need to be heard and understood; this must trump all else.

Make Diagnosis a Team Effort.

Make the search for the diagnosis a joint project that displays your empathy, not a dry affair that feels invasive and always provide information and education. The patient should walk out feeling both understood and enlightened. Never forget that this evaluation may be a crucial tipping point that can change the patient’s entire future.

Maintain Balance in the First Moments.

There are two opposite types of risk that occur in the first moments of the first interview. Many clinicians prematurely jump to diagnostic conclusions based on very limited data and stay stuck on incorrect first impressions, blinded to subsequent contradictory facts. At the other extreme are those who focus too slowly, missing the amazingly rich information that immediately pours forth on the first meeting with a patient. Patients come in primed to convey a great deal to you, intentionally and unintentionally, through words and demeanor. Maintain balance be extra alert in those first few minutes, but don’t jump quickly to diagnostic conclusions.

Balance Open-Ended with Checklist Questions.

Until DSM-III, training in interviewing skills emphasized the importance of giving the patient the widest freedom of expression. This was extremely useful in bringing out what was most individual in each person’s presentation, but the lack of structure and specific questioning led to very poor diagnostic reliability. Clinicians can agree on diagnosis only if they gather equivalent information and are working off the same database. The desire to achieve reliability and efficiency has led clinicians at some centers to go very far in the opposite direction: They do closed-ended, laundry list interviews focused only on getting yesno answers to questions exclusively based on DSM criteria. Carried to extremes, both approaches lose the patient the former to idiosyncratic free form, the latter to narrow reductionism. Let your patients reveal themselves spontaneously, but also manage to ask the questions that need to be asked.

Use Screening Questions to Hone in on the Diagnosis.

The surest way toward a reliable, accurate, and comprehensive diagnosis is a semistructured interview that combines a wide range of open-ended and closed-ended questions. However, this takes hours to perform and is possible only in highly specialized research or forensic situations, where time is no object and reliability is all-important. The everyday clinical interview necessarily requires shortcuts; you can’t ask every question about every disorder. After listening carefully to the patient’s presenting problems, you must select which branch of the diagnostic tree to climb first. Place the symptoms among the most pertinent of the broad categories (e.g., Depressive Disorders, Bipolar Disorders, Anxiety Disorders, ObsessiveCompulsive Disorder [OCD], Psychotic Disorders, Substance-Related Disorders, etc.). Then ask screening questions (provided for each disorder) to start narrowing down to the particular diagnostic prototype that best fits the patient. Before feeling comfortable with your diagnosis, make sure you explore with the patient the alternative possibilities covered in the differential diagnosis section for that disorder. Ill be giving diagnostic tips that will help you along the way. Always check for the role of medicines, other substances, and medical illnesses in everyone you evaluate.

Remember the Significance of Clinical Significance.

Psychiatric symptoms are fairly ubiquitous in the general population. Most normal people have at least one, and many have a few. When present in isolation, a single symptom (or even a few) do not by themselves constitute psychiatric illness. Two additional conditions must also be met before symptoms can be considered mental disorder. First, they have to cluster in a characteristic way. Isolated symptoms of depression, anxiety, insomnia, memory difficulties, attention problems, and so forth are never by themselves sufficient to justify a diagnosis. Second, the symptoms must cause clinically significant distress or clinically significant impairment in social or occupational functioning. This caveat is so important that it is a central and essential aspect of the differential diagnosis for most of the psychiatric disorders. Keep always in mind that it is never enough to identify symptoms; they must also create serious and persistent problems.

Conduct a RiskBenefit Analysis.

In tossup situations, weigh the pluses and minuses of giving the diagnosis. The basic question boils down to Is this diagnosis more likely to help or more likely to hurt? All else being equal when decisions could go either way, it makes sense to make a diagnosis when it has a recommended treatment that has been proven safe and effective but to withhold a questionable diagnosis if there is no proven treatment or if the available treatment has potentially dangerous side effects. Stepped diagnosis (see below) provides time for the clinical picture to declare itself and for you to get a deeper understanding of it.

Dont Misunderstand Comorbidity.

In order to facilitate reliability, DSM is a splitter’s (not a lumper’s) system; the diagnostic pie has been cut into many very small slices. Many patients present with more than one cluster of symptoms and require more than one diagnosis. Noting all the pertinent diagnoses adds diagnostic precision and provides a more rounded view of the person. But having more than one disorder doesnt mean that each is independent of one another, or that they require separate treatments. The DSM mental disorders are no more than descriptive syndromes; they are not necessarily discrete diseases. The multiple diagnoses may reflect one underlying etiology and may respond to one treatment. For example, Panic Disorder and Generalized Anxiety Disorder may be just two faces of the same tendency toward problems with anxiety. It is useful to have separate categories for each because some people have only panic symptoms and others only generalized anxiety symptoms. Having separate categories adds information and precision, but should not imply separate causalities or need for separate treatments. Misunderstanding comorbidity can lead to harmful polypharmacy if a clinician believes incorrectly that each mental disorder necessarily requires its own treatment.

Be Patient.

With some people, things are so clear-cut that the diagnosis jumps out in five minutes. But with others, it may take 5 hours. With still others, it may require five months or even five years. Diagnostic impressions are useful hypotheses to be tested, not blinders that can cause you to miss newer information or the bigger picture. If you rush into a diagnosis, serious mistakes can be made.

Dont Be Ashamed to Use the Unspecified Categories.

How simple it would be if our patients symptoms conformed closely with the neat little packages that are contained in the DSM definitions. But real life is always so much more complicated than what is written down on paper. Psychiatric presentations are heterogeneous and overlapping and often have the fuzziest of boundaries. Lots of times, someone has symptoms that bespeak the presence of a mental disorder, but that dont fall precisely within the boundaries of any one of the named DSM categories. This is the reason why the many Unspecified categories are sprinkled so liberally throughout DSM-5. These categories provide indispensable placeholders when patients definitely need a diagnosis, but don’t fit existing molds. Without them, the diversity of human suffering would require that we include an ever-expanding list of additional new mental disordersthus risking overdiagnosis and burying the system in unmanageable complexity.

Psychiatry has many shades of gray that are lost with black-and-white thinking. Using the Unspecified label reflects and announces that there is an appreciable level of diagnostic uncertainty a useful thing when the simple, fast answer is so often wrong and harmful. Uncertainty can arise when there is insufficient information, or when a patient has an atypical or subthreshold presentation, or when it is unclear whether substances or medical illnesses are causing the symptoms. The Unspecified designation implies that we will need to extend the evaluation and learn much more before committing ourselves. Admitting uncertainty is a good first step to accurate diagnosis. Pseudoprecision is no precision, and premature certainty brings no certainty; instead, both lead to the dangerous unintended consequences of unnecessary stigma and excessive medication treatment.

Suppose that a patient has an apparent depression, but it is not yet clear whether the symptoms constitute a primary Depressive Disorder, are secondary to alcohol use or to a medical illness, are medication side effects, or are some combination of these. Until the picture comes into clearer focus, Unspecified Depressive Disorder is just the ticket. Or suppose that a teenager presents with a first onset of psychotic symptoms, and it is too soon to tell whether this is a Bipolar Disorder, Brief Psychotic Disorder, or the result of multiple secret LSD trips. Stick with Unspecified Psychotic Disorder until time (ideally) tells all. Don’t ready, fire, aim.

There is one important disclaimer. Wonderful and necessary as the Unspecified categories are in clinical practice, they are unreliable and completely useless in forensic proceedings and should never be taken seriously if offered as expert testimony. Forensic work requires a much higher degree of precision and agreement than can ever be afforded by the Unspecified diagnoses.

Be Cautious about Other Diagnoses.

DSM-5 has introduced a new convention that I consider risky. For many categories, the clinician can code Other as in Other Psychotic Disorder, Other Mood Disorder, Other Anxiety Disorder, or Other Paraphilic Disorder. I object to this because it provides a back-door way to diagnose proposed conditions that have been explicitly rejected by DSM-5 or relegated to the appendix for disorders requiring further study, such as Attenuated Psychosis Syndrome, Mixed Anxiety/Depression, Coercive Paraphilia, Hebephilia, Internet Addiction, Sex Addiction, and so forth. These have all been rejected or kept at arms length for very good reasons and should not be used casually in clinical or forensic practice. For the sake of consistency, I sometimes include codes for the Other categories, but I omit them when they are particularly likely to be misused.

Constantly Test Your Subjective Judgments.

There are no biological tests in psychiatry, and (with the exception of tests for dementia) none are in the pipeline for at least the next decade. Psychiatric diagnosis depends completely on subjective judgments that are necessarily fallible, should always be tentative, and must constantly be tested as you know the patient better and see how the course evolves. The more information the better, especially since people aren’t always the most accurate reporters about themselves. Whenever possible, speak with family members and other informants, and also get records (both medical records and records of any previous psychiatric or other mental health treatments). You shouldn’t necessarily believe past diagnosespeople change, and diagnostic errors are frequentbut you should take them into account. And whenever treatment isn’t working, always reconsider the diagnosis.

Always Document Your Thinking.

By itself, a diagnosis is just a naked label. It will help your clinical thinking and your longitudinal followup (and protect you from malpractice suits) if you also provide a clear rationale for your conclusions as you are forming them. What are the factors in the patient’s current presentation, personal history, course, family history, and previous treatment response that most guided your thinking? What are the unanswered questions and areas of continuing uncertainty? What will you be looking for in future visits? Good documentation is a sign of, and also a guide to, good diagnostic practice.

Remember That the Stakes Are High.

Done well, psychiatric diagnosis leads to appropriate treatment and a good chance for cure or at least substantial improvement. Done poorly, psychiatric diagnosis leads to a nightmare of harmful treatments, unnecessary stigma, missed opportunities, reduced expectations, and negative self-fulfilling prophecies. It is worth the time and effort to become really good at psychiatric diagnosis. Being a competent diagnostician wont guarantee that you are a complete clinician, but it is impossible to be even a satisfactory clinician without good diagnostic skills.

Interested in the book? Check it out at Essentials of Psychiatric Diagnosis: Responding to the Challenge of DSM-5