Background: Delirium occurs in approximately 1 in 5 general hospital admissions and up to 85% of patients with terminal illness, but can be difficult to differentiation from other disorders, such as depression.
Objective: The authors assessed and compared mood states as they relate to onset of delirium.
Method: Symptoms of depression and delirium were assessed in 100 consecutive palliative-care admissions immediately after admission and 1 week later.
Results: Overall, 51% experienced either major depression or delirium. Most patients with syndromal delirium also met criteria for major depressive illness, and 50% of those with depression had delirium or subsyndromal delirium (SSD). Delirium symptoms were less common in patients with major depression than depressive symptoms in patients with delirium or SSD.
Discussion: Delirium should be considered in patients with altered mood states, and screening for depression should initially rule out delirium. Sustained alterations in mood may be more frequent in delirium than previously recognized.