How Thoughts Become a Psychiatric Diagnosis

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.

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.

[Reuters/Carlos Barria]

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.

Sometimes the feelings that are felt by a clinician -- either in empathy for a person or in "countertransference," where emotions are stirred in the doctor in response to those the patient is feeling -- can be useful, if sometimes imprecise. Some of the most notable moments of this phenomenon surface in the media when a doctor's sexual desires are mobilized in response to his or her patient -- and then acted upon. The feeling activated in the doctor may be diagnostically informative in understanding a patient's internal state but acting on this countertransference is unethical and destructive.

Empathy can also be useful, but it must be managed. I (LIS) recall feeling discouraged after spending time with depressed patients. I had to tell myself that I was not getting depressed but instead feeling what my patient was feeling. In those instances, I had to be sure to not voice the same bleak outlook as my patient since that wasn't true (beyond the moment), nor would it be helpful. Detecting my empathic feelings, importantly, was diagnostic information, and useful. But only if I kept my feelings to myself.


Psychiatrists routinely begin with: "Tell me what brings you here. When did your problems start? And then what happened?" With further inquiry we uncover information about what makes the condition worse or better. Sometimes the information obtained reveals a pretty clear picture. For example, an unrelenting blue mood, guilt, trouble sleeping, loss of appetite, reduced libido, hopelessness, and a wish to end one's life fits the profile of a major depression (duration is another data point, if subjective in nature, with depressive signs and symptoms needing to persist at least two weeks).

At other times, the clinical picture is too vague to tell: loss of energy, wanting to avoid others, trouble concentrating, for example, are worrisome and interfere with functioning but do not sufficiently, or specifically, portray what is going on. But the diagnostic process remains the same: keen observation, active listening, and pattern recognition. This is the great art of medical diagnostics: age-old yet as relevant today as it was when Hippocrates, the Greek father of medicine, was evaluating patients.

What is going on in the doctor's mind is called 'differential diagnosis' -- a systematic process of telling two (or more) conditions apart. This is medical detective work at its finest, and television has capitalized on its intrigue (House having lasted eight seasons). As a patient, you may hear this as "...while you may have depression, it is possible there is a problem with your thyroid or other physical problem, or your heart medicine may have unwelcome side effects that cause low mood and energy...we need to find out more." For general medical conditions the 'more' is typically blood tests and scans; for psychiatry it is more history, observation (by patient, significant others, and clinicians), and time.

For new onset emotional problems, especially those that develop absent a clear psychological stressor, your doctor needs to 'rule out' other conditions. A doctor will want to determine if the symptoms and signs may be caused by a physical illness, side effects of a prescribed medication(s), or by drugs and alcohol used in excess and disrupting the fragile equilibrium of our nervous system. Common examples of medical conditions that can produce emotional problems include hypo- and hyperthyroidism, mononucleosis, autoimmune diseases like systemic lupus and multiple sclerosis, and early stage malignancies. Identifying these physical conditions also requires a careful history, a thorough physical examination, blood tests and sometimes an imaging study or biopsy.

A black mark remains in the history of psychiatry as a consequence of an incomplete differential diagnosis of George Gershwin. At the height of his career, at 36, while beginning to write "Porgy and Bess," the great composer began to suffer depressive symptoms. He entered psychoanalysis but his condition worsened. In time, he began to lose his coordination, have severe headaches and smell unusual odors. He had a brain tumor. He died during a surgical effort to remove the tumor that had grown massively in the two years since his symptoms began. Differential diagnosis can make a difference between life and death, back in the 1930s and still today.

The use or abuse of alcohol, non-prescribed medications, or street drugs often confounds persistent psychiatric symptoms and diagnosis. The person suffering from addiction is frequently impaired in their day-to-day functioning, mood, and thinking. Alcohol abuse can cause depressed feelings as well as disinhibit humans who then are apt to engage in dangerous or troublesome behaviors. Amphetamines of all types, especially methedrine, deplete the brain of essential neurotransmitters and can produce excitement or psychosis. Ecstasy is neurotoxic. Narcotic analgesic pills like OxyCodone™ and Vicodin™ taken abusively produce withdrawal and serious mood problems. The various psychiatric complications of substance use and abuse are called organic mood (or cognitive or psychotic) disorders.

Collateral information, from family, friends, school and others, may be needed to detect a substance abuse disorder that is inducing psychiatric symptoms or aggravating other mental disorders. While blood and urine tests often can detect the presence of these substances, unfortunately brain imaging (e.g. MRIs, EEGs, PET Scans) cannot. Despite two decades of spectacular neuroimaging advances to our understanding of the brain's anatomy, physiology and reward pathways, its use in diagnostic decisions has yet to be integrated into clinical practice. Nor does psychiatry have accurate biological markers to guide a substance abuse diagnosis.

This is not due to lack of trying, but rather the result of how complex the brain is to comprehend. We do know what happens to the brain on drugs: the image of the egg frying on a pan -- from a brilliant ad campaign led by the Partnership for A Drug Free America in the late 1980's that promoted "This is your brain on drugs" -- illustrates the destructive power of drugs even if we cannot reliably demonstrate it on an MRI (until too much brain tissue is gone and it is too late!).

A throat swab with a rapid Strep test quickly diagnoses the absence or presence of an infection ("yes or no") and a bone densitometry [DEXA] scan indicates risk for osteoporosis by comparing the individual's results as compared to a comparable population's. But a diagnosis of addiction is far more complex with genetics and the environment at work and to date an inability to discern a neurobiological condition from a recreational one.

Yet, simple questionnaires that assess symptoms are quite effective in detecting mental health and substance use disorders. Such checklists are now standard screening tools in primary care practices as well as in mental health centers as a first step in unearthing common drug induced conditions (SBIRT is an evidence based screen and early intervention for people with problems with alcohol and drugs and can be accessed here. The Patient Health Questionnaire-9 (PHQ-9) is a highly reliable and valid self-report for depression available in nine languages).

Sometimes, the tail can wag the dog of diagnosis. An illness may be revealed over time when, for example, a patient responds to a treatment. Response to a mood stabilizer like lithium or valproate acid supports the diagnosis of bipolar disorder. Improved symptoms due to antidepressants might support a diagnosis of a psychiatric disorder, but it may not help distinguish a depressive illness from an anxiety disorder since antidepressants help both conditions. The logic of the diagnostic process is deductive. Deductive reasoning is the method of Sir Conan Doyle's Sherlock Holmes (and his heirs from Lt. Columbo to Dr. House) -- a valuable and timeless means to untangle the mysteries of many a science.


There are times, though infrequent, when special brain scans (Magnetic Resonance Imaging or MRI) are needed, and times when psychological tests can be helpful. Neuroimaging, or radiological tests of the brain or spinal nervous system, can assist in diagnosis when used to examine for a physical illness that could explain a person's disorder. Depending on the study, a brain scan can look at anatomy or at the functioning of the brain. Brain scans are commonly used to detect tumors, blood vessel or bleeding abnormalities, skull fractures, or loss of brain tissue (as seen in Alzheimer's disease and the more recent promise to detect it early).

But, these scans are not employed for initial psychiatric diagnosis. Instead, scans are used to determine the absence of a neurological lesion, rather than pointing out the presence of a behavioral condition. MRI's cannot diagnose schizophrenia or bipolar disorder, but they can identify a tumor or a stroke that may have similar psychiatric manifestations. While we are seeing truly fascinating results from neuroimaging -- from unraveling complicated brain depression networks to staging dementia -- it has yet to serve as an anchor for psychiatric diagnosis.

Psychological testing has come a long way from the days of Rorschach's inkblots. Intelligence and other tests of cognitive functioning, administered by an expert psychologist, can help to identify problems with mental attention, focus, and decision-making. There are tests that can help in the workplace, the best known being the Myers-Briggs, which profiles how people think and feel -- and can be useful in understanding (and getting along with) our co-workers. There are tests that can track the progression of dementia. The mother who asked about psychological testing was wondering if personality and projective (looking into the workings of the mind) testing could make a difference in diagnosis. Not today, we say.

For over a decade, scientists have been detailing the human genome and trying to target treatments based on individual genes that might predict response (or lack of it) to specific treatments. Patients, families, and practitioners have remained hopeful that genetic evaluations will influence clinical decisions. Dr. Harold Varmus, former head of the National Institutes of Health, said -- and we paraphrase -- the human genome is good for science but not for medicine. You or your family member may want to participate in rigorous and safe psychiatric genetic research, but don't waste your time, money and precious hope on a gene that someone says will change the course of treatment or recovery. Not yet. And while you consider imaging to rule out other physical disorders, these scans are, alas, not yet able to establish a psychiatric diagnosis. Soon, we hope.


Mental disorders are rapidly becoming the leading causes of disability worldwide.

They also contribute substantially to the burden of the chronic physical illnesses (like heart disease, asthma, diabetes, cancer, and stroke) that now dominate global public health. We need better psychiatric diagnostics (and treatments). Neuroscience research continues to reveal more about the brain and is the path for the discoveries we so deeply need.

But until scientific inquiry yields results that can be used in everyday clinical practice, too many people remain ill, impaired, and at risk of taking their lives. For now, when an illness eludes our ability to explain its cause(s) or persists in you or your loved one, you will want to be prudent - and not a desperate shopper. You can and should seek further consultation and more careful evaluation. But be wary of diagnostic tests (and treatments) that are not yet ready for prime time.

Instead, learn about your condition. With your doctor, and other caregivers, relentlessly monitor response to treatment and insist on proven diagnostic inquiries and treatments that are comprehensive and continuous in their delivery. When improvement is not happening, ask why -- and insist on an answer. Seek out caregivers who are firmly rooted in the conviction that you can get better and live a life like everyone else. Don't settle for less. There is so much that can be done to help people with mental illnesses, even if the tests are not yet here to tell us why the treatments work.