From the Guidelines
Acute delirium is consistent with a time frame of a short period of time.
Definition of Acute Delirium
According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), as cited in the study 1, delirium is defined by a disturbance in attention and awareness that:
- Develops over a short period of time
- Fluctuates
- Is accompanied by a change in cognition The DSM-5 criteria emphasize that these disturbances are not explained completely by an established or evolving neurocognitive disorder/injury, and there is evidence that the disturbance is caused by a direct physiologic consequence of a medical condition, an intoxicating substance, medication use, or from multiple etiologies. Key points of the definition include:
- Short period of time: The time frame is not strictly defined, but it is generally understood to be hours to days, rather than weeks or months.
- Fluctuating course: Delirium is characterized by a fluctuating course, with symptoms worsening and improving over a short period of time.
From the Research
Time Frame for Acute Delirium
The time frame consistent with acute delirium according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) is not explicitly stated in the provided studies. However, the characteristics of delirium are described as an acute change in cognition and a disturbance of consciousness, usually resulting from an underlying medical condition or from medication or drug withdrawal 2, 3.
Duration of Delirium
Studies have reported varying durations of delirium, including:
- An average duration of 4 days in patients with ischemic stroke and 3 days in patients with hemorrhagic stroke 4
- A longer duration of delirium in women and in patients older than 65 4
- Delirium lasting from a few hours to several days or even weeks 3
DSM-5 Criteria for Delirium
The DSM-5 provides new criteria for delirium diagnosis, which have been compared to the DSM-IV criteria in several studies:
- A study found that the concordance between DSM-IV and DSM-5 criteria for delirium diagnosis was 53% using strict DSM-5 criteria and 91% using relaxed DSM-5 criteria 5
- Another study found that different classification systems for delirium, including DSM-5, DSM-IV, CAM, and DRS-R98, identify populations with different outcomes 6