The Medical Director of the New York State Office of Mental Health explains the misunderstood art of diagnosis in the medical specialty where, in even the sickest patients, the best blood tests and imaging studies often appear normal.
After listening to a public talk, a mother lingered to ask whether or not her 23-year-old son -- recently thwarted in his college studies by serious depression and anxiety -- should have a brain MRI to see if there is something abnormal. At a neighborhood diner, another concerned mom wondered if psychological testing for her adolescent daughter might decipher the origins of her child's struggle with anxiety and eating problems. At work, a worried father asked if gene testing would be helpful to understand his daughter's psychiatric illness, which had recently erupted.
These were questions asked of the first author of this article, and the answers were all pretty much the same: these tests are not apt to provide any clinically useful information for diagnosis (or treatment) and can raise further unanswerable and confounding questions.
Diagnosing disorders of the mind is a difficult business. As a medical specialty, psychiatry currently lacks blood, imaging and genetic tests that can validly establish a diagnosis for its vast predominance of major illnesses. While there are spectacular advances in functional brain imaging, genomic analysis, and cognitive neuroscience, these research findings have not yet meaningfully added to our understanding of how the brain's malfunctions produce its myriad of mental pathologies.
Psychiatry, thus, has a diagnostic predicament. Whereas rapid blood assays, biomarkers, and computer-aided diagnosis are revolutionizing doctors' diagnostic abilities and improving their clinical decision-making, behavioral medicine lacks these definitive diagnostic tests. Instead, interrogative poking and prodding, descriptive criteria, and symptomatic checklists are the best the field has to offer.
Ironically, this knowledge gap exists alongside a legion of effective treatments in behavioral health. The field of psychiatry knows what works, but not exactly why. Our understanding of the brain (and how to treat its disorders) is empirical. Psychiatric medicine, with its biological and psychological interventions, has achieved considerable effectiveness in improving a sufferer's symptoms and conditions -- though the "how" or "why" these treatments work continues to elude scientific comprehension. Understandably, this state of affairs has stimulated ample criticism and skepticism about psychiatry.
Let's say a fifty-year old man walks into a psychiatrist's office complaining of headaches, fatigue, and poor concentration. He lets the doctor know that he's not thrilled about seeing a psychiatrist -- it's his first time seeing a shrink -- but his wife is very worried about his recent downcast mood and thinks talking to a professional might help. The psychiatrist takes a history and proceeds in search of a diagnosis: Is this a new or existing condition? Are there recent relationship, employment, or fiscal stressors? Are there other significant conditions and medications that might contribute to his change in behavior? What medical conditions should be considered? Does this fellow use or abuse substances? The psychiatrist uses exhaustive questioning and a decision algorithm to hone in on a select few diagnoses. Medical tests are then usually needed to exclude some obvious, but dangerous conditions. But, how can a patient, or family, avoid unnecessary, confusing and expensive tests that are not ready for prime time? And once treatment begins how can the doctor and patient know what further diagnostics or ongoing assessments may be needed to stay the course or make mid-course corrections?
Any illness, physical or mental, is a complex of symptoms (what a person feels - such as fatigue or nausea or nervousness), signs (what can be observed or measured - such as increased blood pressure, shortness of breath, hand wringing or weight loss), and data (objective measures of an illness -- such as thyroid hormones, blood sugar, abnormal cells from a mass, or lesions on an x-ray or MRI scan). OCD, Obsessive Compulsive Disorder, provides a good example of the distinction between symptoms and signs, and the absence of data: In this condition, a person experiences obsessions or compulsions, or both.
Obsessions are symptoms, such as thoughts or impulses, which gnaw away at someone's mind, even though the sufferer knows that the thoughts are unreasonable. Obsessions are more than just worries like: Did I remember to leave a note for friend who is staying at my apartment? Another symptom of the condition is anxiety, manifest as anxious thoughts, such as: Did I turn off the stove (after checking it 25 times)? Will I be exposed to infection if I touch any surface in the classroom?
Compulsions are signs: they are visible, repetitive actions by a person in response to a particular anxiety provoking idea (despite knowing that these are irrational and foolish behaviors). Some examples of compulsions are: I will count to forty, forty times and only then I can leave the house safely; If I touch my index and thumb fingers while saying the Lord's Prayer, then nothing bad will happen to my children; or I must wash my hands just one more time (after ten minutes of scrubbing red hands that are chapped from previous washings), then I can return to work.
OCD can be a crippling anxiety disorder. Yet, as severe as it is, there is no laboratory or imaging test that substantiates its biological or physiological causes. The data is gathered by history and observation -- not by the results of a blood specimen or a CT scan. There is nothing unusual about this state of affairs in psychiatry.
As a rule, a diagnosis is not made from a blood value or pathology slides examined under a microscope, or from radiology (including X-rays and imaging) findings. But in psychiatry it mostly comes from listening, observing, and asking the person affected -- and others who have witnessed that person firsthand -- to describe what has happened. The process starts with the old-fashioned approach of a doctor taking a careful history, asking how a person feels, and observing how he or she looks, acts, and thinks.