Diagnosis of psychiatric disorders not as important as outcomes

Nailing the diagnosis of a psychiatric disorder may not be important in prescribing effective treatment, according to Mark Zimmerman, M.D., a clinical researcher at Rhode Island Hospital. His opinion editorial was published online today in the Journal of Clinical Psychiatry.

"During the past 35 years, we have witnessed a revolution in the treatment of psychiatric disorders," said Zimmerman, director of outpatient psychiatry and the partial hospital program at Rhode Island Hospital and director of the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project, a study that integrated assessment tools and procedures of researchers into a hospital-affiliated outpatient practice. "Prescription medicine and therapy are effective for a wide range of psychiatric disorders, thus the need for precise diagnosis is often unnecessary."

Zimmerman and his research cohorts compared unstandardized, unstructured interviews to standardized, structured interviews used by clinicians across the country. They found that the semi-structured interview provides more diagnoses, a finding that was replicated in other studies. While several of the initial reports from the MIDAS project identified problems with the detection of disorders, with regards to the diagnosis of bipolar disorder the researchers observed an opposite phenomenon - clinician over-diagnosis.

"Even if misdiagnosed, patients' outcomes may not be worse because the medications prescribed are effective for a variety of conditions," said Zimmerman. "Most outpatients will find relief via antidepressant or antipsychotic medications. Medications such as selective serotonin reuptake inhibitors (SSRIs), and serotonin-norepinephrine reuptake inhibitors are effective for depression, almost all anxiety disorders, eating disorders, impulse-control disorders, substance use disorders, attention deficit disorder and some somatoform disorders. Thus, it is possible that accurate and comprehensive diagnostic evaluations are not as critical once the provider determines the gross diagnostic distinction (i.e., distinguishing between psychotic, mood and/or substance use disorders)."

While a diagnostic determination is an important function of the intake evaluation, it is not the sole objective, opined Zimmerman. Comprehensive diagnostic evaluations may be associated with greater patient satisfaction and adherence to prescribed courses of treatments, he pointed out.

The National Institute of Mental Health estimates that nearly one in five Americans suffers from mental illnesses as defined in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders.

Zimmerman's principal affiliation is Rhode Island Hospital and The Miriam Hospital, members of the Lifespan health system in Rhode Island. He also has an academic appointment at the Alpert Medical School of Brown University, department of psychiatry and human behavior.