Delirium Causes & Effects

The signs, symptoms, and effects of delirium can look different for each person impacted. Learning about delirium is one of the first steps toward healing.

Understanding Delirium

Learn about delirium

Delirium is a condition that is classified as a neurocognitive disorder, which involves attention and other cognitive disturbances that can emerge within a few hours or days. The marked disturbances can be observed by others because the psychological changes that occur are often quite different from the individual’s baseline functioning. Those who are experiencing an episode of delirium may not be able to remember certain details about themselves, may feel disorientated, may be unable to speak or understand information clearly, and/or may have a poor perception and awareness of their surroundings.

In order for an individual to be diagnosed with delirium, he or she must be thoroughly evaluated to determine if this condition was caused by a medical condition, medication, some other substance, such as a drug or alcohol, exposure to a toxin, or a combination of all or some of these influences. And while delirium symptoms can last just a few hours or days, there are some people who suffer from delirium for weeks or months. Early detection of delirium is imperative in order to treat any existing symptoms and so that the underlying causes of a delirium episode(s) can be identified and treated as well. In doing so, the negative effects that can result from delirium can be successfully prevented or avoided all together.


Delirium statistics

Delirium is most often diagnosed among individuals who are of older age. Approximately 1 to 2 percent of the general population will meet diagnostic criteria for this condition, though nearly 14 percent of adults over the age of 85 will suffer from delirium at some point. Of those who are admitted to hospitals, research shows that 14 to 24 percent of those admissions are due to symptoms of delirium being present. Furthermore, it is believed that this condition is diagnosed in 15 to 53 percent of senior adults following a surgery and in 70 to 87 percent of older adults who have required intensive care.

Causes and Risk Factors

Causes and risk factors for delirium

Delirium is known to be caused by a number of genetic and environmental influences that can ultimately lead to the onset of symptoms. In addition to these influences, there are certain risk factors that can make a person more vulnerable to experiencing an episode of delirium. Consider the following:

Genetic: Those with a genetic history of neurocognitive disorders, such as Alzheimer’s disease, are more susceptible to experiencing delirium. Additionally, there are certain heritable medical conditions that warrant certain medications that could cause an episode of delirium.

Environmental: Exposure to certain toxins and the ingestion of certain substances can lead to the onset of delirium symptoms, both of which are considered to be environmental influences for the onset of delirium. Especially if a person is exposed to or consumes a substance that can cause significant mind and mood altering effects, there is a higher likelihood that a delirium episode can occur.

Risk Factors:

  • Personal history of substance abuse
  • Being of older age
  • Being required to take certain medications, such as those that treat mood disorders, sleep problems, asthma, allergies, or progressive diseases – especially those that have psychoactive properties
  • Suffering from an illness that causes a high fever or infection (in children / adolescents)
  • Malnutrition
  • Suffering from a terminal illness

Signs and Symptoms

Signs and symptoms of delirium

The telltale signs and symptoms of delirium typically manifest over a short period of time and can be observed by others. Depending on the cause of an episode of delirium, the following symptoms may be present, represent a change in a person’s regular ability to sustain attention and awareness of his or her surroundings, and should be addressed by a mental health professional as soon as possible:

Behavioral symptoms:

  • Refusal to abide by recommendations for one’s medical care
  • Slow movement or periods of hyperactivity
  • Wandering
  • Verbal aggression
  • Restlessness
  • Physically aggressive behaviors

Physical symptoms:

  • Fluctuations in energy levels
  • Sleep disturbances

Cognitive symptoms:

  • Inability to focus or sustain attention
  • Lack of awareness of one’s surroundings
  • Memory impairment
  • Disorientation
  • Loss of language ability
  • Difficulty with learning, reading, and/or writing
  • Hallucinations
  • Delusions

Psychosocial symptoms:

  • Increased irritability
  • Mood fluctuations
  • Agitation
  • Anxiety
  • Depressed mood
  • Anger
  • Feelings of euphoria
  • Apathy
  • Feelings of fear


Effects of delirium

There can be many consequences of delirium. Depending on the mental and physical health of the person suffering from this condition, the effects can vary. The following are among the effects that can occur as a result of experiencing symptoms synonymous with delirium:

  • Greater need for inpatient hospitalization
  • Greater need for placement in a nursing home (among older adults)
  • Decline in physical health, which could result in the onset of new or worsening of existing physical health concerns
  • Difficulty recovering from surgery
  • Decline in cognitive functioning
  • Elevated risk for death

Co-Occurring Disorders

Delirium and co-occurring disorders

When an individual is suffering from delirium, the onset of symptoms is often the result of an underlying medical condition, the consequence of consuming a substance, or exposure to some type of contaminant. Depending upon an individual’s medical history, substance or medication use history, and environments in which that person is exposed to, the co-occurring conditions that a person can suffer from at the same time as delirium can be vast. When seeking out a mental health evaluation for delirium, it is important for these factors and other such information to be reported to the assessor in order to effectively conclude that delirium is the cause of the change in a person’s cognitive functioning.

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