The authors’ observations
CJD is a rare, rapidly progressive, fatal form of dementia. In the United States, the incidence is approximately 1 to 1.5 cases per 1 million people each year.2 There are various forms of the disease. Sporadic CJD is the most common, representing 85% of cases.3 Sporadic CJD typically occurs in patients in their 60s and quickly leads to death—50% of patients die within 5 months, and 90% of patients die within 1 year.2,3 The illness is hypothesized to arise from the production of misfolded prion proteins, ultimately leading to vacuolation, neuronal loss, and the spongiform appearance characteristic of CJD.3,4
Psychiatric symptoms have long been acknowledged as a feature of CJD. Recent data indicates that psychiatric symptoms occur in 90% to 92% of cases.5,6 Sleep disturbances and depressive symptoms, including vegetative symptoms, anhedonia, and tearfulness, appear to be most common.5 Psychotic symptoms occur in approximately 42% of cases and may include persecutory and paranoid delusions, as well as an array of vivid auditory, visual, and tactile hallucinations.5,7
There is also evidence that psychiatric symptoms may be an early marker of CJD.5,8 A Mayo Clinic study found that psychiatric symptoms occurred within the prodromal phase of CJD in 26% of cases, and psychiatric symptoms occurred within the first 100 days of illness in 86% of cases.5
Case reports have described patients with CJD who initially presented with depression, psychosis, and other psychiatric symptoms.9-11 Interestingly, there have been cases with only psychiatric symptoms, and no neurologic symptoms until relatively late in the illness.10,11 Several patients with CJD have been evaluated in psychiatric ERs, admitted to psychiatric hospitals, and treated with psychiatric medications and ECT.5,9 In one study, 44% of CJD cases were misdiagnosed as “psychiatric patients” due to the prominence of their psychiatric symptomatology.8
Continue to: Making the diagnosis in psychiatric settings