I chaired the APA workgroup that authored the third edition of the treatment guideline for major depressive disorder (MDD), published at the end of 2010. MDD is a typical DSM-3 (and beyond) diagnostic category—a behavioral syndrome, which doubtlessly encompasses many biologically distinct diseases. (Hence the varied responses of patients to our ministrations.) But even while we eagerly await the dawning of the era of personalized, genomically informed medicine in psychiatry, we can still assess each depressed patient with a careful differential diagnosis—considering substance abuse, medical and neurologic diseases, and personality disorders, among other possibilities.
This came to mind when a resident presented a case to me. The chief complaints were lack of energy and interest—certainly key components of MDD, but easily reflecting a host of other diagnoses. When I saw the middle-aged man, he had mask-like facies, bradykinetic features, and a resting tremor. On examination he displayed muscular rigidity. We referred the patient to a neurologist, who confirmed a diagnosis of Parkinson disease. The patient’s psychiatric complaints responded favorable to the antiparkinson regimen, as did his motor signs. We will soon taper his SSRI. It didn’t take long, and it sure helped this man.
-Alan J. Gelenberg, M.D.
Editor, Biological Therapies in Psychiatry
Shively/Tan Professor and Chair, Psychiatry, Penn State University
Editor-in-Chief, Journal of Clinical Psychiatry