Which statement about delirium is accurate?
1) Patients with delirium have higher mortality rates.
2) Delirium is believed to be tied to abnormalities in potassium levels resulting in hyperexcitability of neuronal firing.
3) Delirium can be distinguished from schizophrenia by the lack of psychosis associated with delirium.
4) For a diagnosis of delirium, symptoms cannot be attributable to the effects of a drug or a medical condition.
