Medical mimics: Differential diagnostic considerations for psychiatric symptoms.

Patients with underlying medical disease can present to the health care system with psychiatric symptoms predominating. Identification of an underlying medical condition masquerading as a psychiatric disorder can be challenging for clinicians, especially in patients with an existing psychiatric condition. The term or has been used to describe this clinical situation. Diagnostic categories from , that may encompass medical mimics include substance-induced disorders, which includes medications, and unspecified mental disorder due to another medical condition in situations where the clinician may lack needed information for a complete diagnosis. At this time, there is no single diagnostic test or procedure available to differentiate primary versus secondary psychosis on the basis of psychopathology presentation alone. When considering a diagnosis, clinicians should evaluate for the presence of atypical features uncharacteristic of the psychiatric symptoms observed; this may include changes in functionality and/or age of onset and symptom presentation severity. The purpose of this work is to provide a structured clinical framework for evaluation for medical mimics, identify groups considered to be at highest risk for medical mimics, and present common syndromic features suggestive of a medical mimic. Selected case scenarios are used to illustrate key concepts for evaluating and assessing a patient presenting with acute psychiatric symptomatology to improve judgment in ruling out potential medical causality.