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should take care when diagnosing delirium in people from another culture or a
different background. Such individuals may respond to the clinician’s questions in
ways that suggest delirium, but the clinician should consider whether a patient’s
culture or background, along with anxiety or symptoms of other disorders, might
better account for the apparent cognitive diffi culties.Understanding Delirium: A Side Effect?
Delirium can arise from ingestion of a substance, such as alcohol or a prescribed
medication, or as a result of a medical condition, such as an infection.Delirium That Arises From Substance Use
Delirium can arise from the effects of a psychoactive substance such as alcohol or
a medication, or from withdrawal from such a substance. According to DSM-IV-
TR, intoxication or withdrawal are considered to give rise to delirium only when
the symptoms are signifi cantly more severe than those that usually occur during
intoxication or withdrawal. The symptoms must be severe enough that they require
more than the usual attention and treatment provided to someone who used the
substance in question. If the symptoms are not severe enough to reach the level
needed for a diagnosis of delirium, the appropriate diagnosis is a substance-related
disorder, either intoxication or withdrawal (see Chapter 9).Delirium That Arises From Intoxication
When intoxication causes delirium, only a brief time elapses between taking the
substance and the emergence of delirium symptoms—minutes to hours. Among
older adults, delirium often arises after taking medication on doctor’s orders: One
study found that up to 20% of older adults are prescribed potentially inappropriate
medications (Zhan et al., 2001), which can create unnecessary side effects and inter-
act with other medications to affect cognition and mood.
Most frequently, when the intoxication has worn off, the delirium ends. There
are exceptions, however: Some substances, such as PCP, can produce extended delir-
ium. Moreover, some people may have persistent symptoms of delirium even when
no longer intoxicated.Delirium That Arises From Substance Withdrawal
Sometimes, a chronic user of a substance such as alcohol or a hypnotic-sedative can
become delirious after stopping the substance use. In fact, delirium tremens (the DTs)
arises from withdrawal after alcohol dependence. Depending on the individual and the
substance involved, the symptoms of delirium can last from a few hours to 2–4 weeks.
The diagnosis of delirium is made only when the cognitive problems associated with with-
drawal are signifi cantly more severe than is usual upon withdrawal from the substance,
and the symptoms require the attention of medical or mental health professionals.Delirium Due to a General Medical Condition
Like a fever, delirium can arise for a variety of medical reasons:infection,•- dehydration,
- electrolyte imbalance (which can arise from an eating disorder; see Chapter 10),
stroke,• - brain tumor,
- pneumonia,
- heart attack,
- head trauma, or
- surgery (arising from anesthesia).
Some of these causes, such as dehydration, can be fatal if not treated (Brown &
Boyle, 2002).