This study characterizes the type and timing of psychiatric manifestations in sporadic Creutzfeldt-Jakob disease (sCJD). Historically, sCJD has been characterized by prominent neurological symptoms, while the variant form (vCJD) is described as primarily psychiatric in presentation and course: A retrospective review of 126 sCJD patients evaluated at the Mayo Clinic from 1976-2001 was conducted. Cases were reviewed for symptoms of depression, anxiety, psychosis, behavior dyscontrol, sleep disturbances, and neurological signs during the disease course. Eighty percent of the cases demonstrated psychiatric symptoms within the first 100 days of illness, with 26% occurring at presentation. The most commonly reported symptoms in this population included sleep disturbances, psychotic symptoms, and depression. Psychiatric manifestations are an early and prominent feature of sporadic CJD, often occurring prior to formal diagnosis.