Misinterpreted neuropsychiatric presentations of medical problems in demented patients.

To the Editor: In a recent issue of the JAOA, Peter Tran, DO, and colleagues1 demonstrate significant associations between neuropsychiatric symptoms and degree of medical illness in patients with dementia. We agree with the authors’ conclusion that recognition of comorbid neuropsychiatric and medical problems is necessary for accurate diagnosis and treatment. We wish to voice our support for the work of Tran and coauthors by further underscoring the danger of attributing changes in mental status to a neuropsychiatric origin, especially in patients with dementia. In an ongoing study at our facility, data reveal that as many as 2.5% of patients admitted to a geropsychiatry service for behavioral problems have an unrecognized medical condition that is causing the behavior problems. Such patients require urgent medical intervention. Many medical conditions have psychiatric symptoms. Patients with cerebrovascular accident, congestive heart failure, diabetic ketoacidosis, drug intoxication or withdrawal, encephalitis, hyperthyroidism, hypoglycemia, systemic and central nervous system infections, lithium and anticonvulsant toxicity, neuroleptic malignant syndrome, prescription drug overdose, subdural hematoma, and uremic and hepatic encephalopathy have been misdiagnosed as having psychiatric illness.2,3 As Tran and colleagues point out, neuropsychiatric symptoms or an altered mental status may be the only symptoms indicative of a medical problem in an elderly patient with dementia. Thus, physicians should not conclude that behavioral problems are due to a behavioral illness without obtaining an adequate history, performing mental status and physical examinations, and obtaining indicated laboratory and radiologic studies.