Table 1

DSM-IV-(Text Revision) criteria for delirium4

  1. Disturbance of consciousness (that is, reduced clarity of awareness of the environment, with reduced ability to focus, sustain, or shift attention)

  2. A change in cognition (such as memory deficit, disorientation, language disturbance) or the development of a perceptual disturbance that is not better accounted for by a pre-existing established or evolving dementia

  3. The disturbance developed over a short period of time (usually hours to days) and tends to fluctuate during the course of the day

  4. Where the delirium is due to a general medical condition – there is evidence from the history, physical examination, or laboratory findings that the disturbance is caused by the direct physiological consequences of a general medical condition

    Where the delirium is due to substance intoxication – there is evidence from the history, physical examination, or laboratory findings of either 1 or 2:

    1. The symptoms in criteria (a) and (b) developed during substance intoxication

    2. Medication use – aetiologically related to the disturbance

    Where the delirium is due to substance withdrawal – there is evidence from the history, physical examination, or laboratory findings that the symptoms in criteria (a) and (b) developed during or shortly after the withdrawal syndrome

    Where delirium is due to multiple aetiologies – there is evidence from the history, physical examination, or laboratory findings that the delirium has more than one aetiology (for example, more than one aetiological general medical condition, a general medical condition plus substance intoxication, or medication side effects)

  5. Delirium not otherwise specified – this category should be used to diagnose a delirium that does not meet criteria for any of the specific types of delirium described. Examples include a clinical presentation of delirium that is suspected to be due to a general medical condition or substance use but for which there is insufficient evidence to establish a specific aetiology, or where delirium is due to causes not listed (for example, sensory deprivation)