In a small study of patients referred to the Johns Hopkins Early Psychosis Intervention Clinic (EPIC), Johns Hopkins Medicine researchers report that about half the people referred to the clinic with a schizophrenia diagnosis didn't actually have schizophrenia. Schizophrenia is a chronic, severe and disabling disorder marked by disordered thinking, feelings and behavior. People who reported hearing voices or having anxiety were the ones more likely to be misdiagnosed.

In a report of the study in the March issue of the Journal of Psychiatric Practice, the researchers say that therapies can vary widely for people with schizophrenia, bipolar disorder, major depression or other serious types of mental illness, and that misdiagnosis can lead to inappropriate or delayed treatment.

The findings, the researchers say, suggest that second opinions at a specialized schizophrenia clinic after initial diagnosis are wise efforts to reduce the risk of misdiagnosis, and ensure prompt and appropriate patient treatment.

"Because we've shined a spotlight in recent years on emerging and early signs of psychosis, diagnosis of schizophrenia is like a new fad, and it's a problem especially for those who are not schizophrenia specialists because symptoms can be complex and misleading," says Krista Baker, L.C.P.C., manager of adult outpatient schizophrenia services at Johns Hopkins Medicine. "Diagnostic errors can be devastating for people, particularly the wrong diagnosis of a mental disorder," she adds.

According to the National Institute of Mental Health, schizophrenia affects an estimated 0.5 percent of the world population, and is more common in men. It typically arises in the late teens, 20s and even as late as the early 30s in women. Symptoms such as disordered thinking, hallucinations, delusions, reduced emotions and unusual behaviors can be disabling, and drug treatments often create difficult side effects.

The new study was prompted in part by anecdotal evidence among health care providers in Baker's specialty clinic that a fair number of people were being seen who were misdiagnosed. These patients usually had other mental illnesses, such as depression.

To see if there was rigorous evidence of such a trend, the researchers looked at patient data from 78 cases referred to EPIC, their specialty clinic at Johns Hopkins Bayview Medical Center, for consultation between February 2011 and July 2017. Patients were an average age of 19, and about 69 percent were men. Seventy-four percent were white, 12 percent African American and 14 percent were another ethnicity. Patients were referred to the clinic by general psychiatrists, outpatient psychiatric centers, primary care physicians, nurse practitioners, neurologists or psychologists.

Each consultation by the clinic took three to four hours, and included interviews with the patient and the family, physical exams, questionnaires, and medical and psychosocial histories.

Of the patients referred to the clinic, 54 people came with a predetermined diagnosis of a schizophrenia spectrum disorder. Of those, 26 received a confirmed diagnosis of a schizophrenia spectrum disorder following their consultation with the EPIC team, which is composed of licensed clinicians and psychiatrists. Fifty-one percent of the 54 cases were rediagnosed by clinic staff as having anxiety or mood disorders. Anxiety symptoms were prominent in 14 of the misdiagnosed patients.

One of the other most common symptoms that the researchers believe may have contributed to misdiagnosis of schizophrenia was hearing voices, as almost all incorrectly diagnosed patients reported auditory hallucinations.

"Hearing voices is a symptom of many different conditions, and sometimes it is just a fleeting phenomenon with little significance," says Russell L. Margolis, M.D., professor of psychiatry and behavioral sciences and the clinical director of the Johns Hopkins Schizophrenia Center at the Johns Hopkins University School of Medicine. "At other times when someone reports 'hearing voices' it may be a general statement of distress rather than the literal experience of hearing a voice. The key point is that hearing voices on its own doesn't mean a diagnosis of schizophrenia."

In speculating about other reasons why there might be so many misdiagnoses, the researchers say that it could be due to overly simplified application of criteria listed in the Diagnostic Statistical Manual of Mental Disorders, a standard guide to the diagnosis of psychiatric disorders.

"Electronic medical record systems, which often use pull-down diagnostic menus, increase the likelihood of this type of error," says Margolis, who refers to the problem as "checklist psychiatry."

"The big take-home message from our study is that careful consultative services by experts are important and likely underutilized in psychiatry," says Margolis. "Just as a primary care clinician would refer a patient with possible cancer to an oncologist or a patient with possible heart disease to a cardiologist, it's important for general mental health practitioners to get a second opinion from a psychiatry specialty clinic like ours for patients with confusing, complicated or severe conditions. This may minimize the possibility that a symptom will be missed or overinterpreted."

Margolis cautioned that the study was limited to patients evaluated in one clinic. Nonetheless, he was encouraged by the willingness of so many patients, their families and their clinicians to ask for a second opinion from the Johns Hopkins clinic. If further study confirms their findings, it would lend support to the belief by the Johns Hopkins team that overdiagnosis may be a national problem, because they see patients from across the country who travel to Johns Hopkins for an opinion. They hope to examine the experience of other specialty consultation clinics in the future.

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Chelsey Coulter of the University of Pittsburgh is also an author on the study.

The study was funded in part by the ABCD Charitable Trust.

Margolis receives grant support from Teva Pharmaceuticals for an unrelated project.