Delirium results in loss of sense of reality, misperception of reality, and / or confusion of ideas. The delusional thought affects the entire personality of the person who has it.

Here is a non-exhaustive list of signs that people with delirium may present:

• an inability to stay focused on a subject

• be easily distracted

• being withdrawn, introverted, having little or no interaction with the environment

• memory problems, especially with regard to recent events

• disorientation

• inconsistent comments

• a recurring speech

• difficulty reading or writing

• of hallucinations

• a feeling of persecution

• erotomania (delusional delusion of being loved by someone), or morbid jealousy

• megalomania

• restless, nervous, irritable behavior

• disturbed sleep

Signs of delirium appear within hours or days. They are unique in that they fluctuate over the course of a day, so that a person with delirium may have periods without symptoms.

Note that delirium and dementia (a group of symptoms affecting memory, sociability, thinking) can present similar signs and can therefore be difficult to distinguish. It is even possible that a person has both disorders. For example, people with dementia may have episodes of delirium. There are, however, simple ways to tell the difference between delirium and dementia:

• delirium sets in quickly as signs of dementia are progressive

• in people with delirium the signs are more or less marked during the day while for dementia the signs are stable over the day, although they may get worse or better the next day 

If there are signs of delirium or dementia, a doctor should be consulted for an accurate diagnosis.

Delirium occurs when the brain is made vulnerable by several factors, and brain activity shows dysfunction.

Some of the factors that can cause delirium include:

• dehydration or malnutrition

• dementia (Alzheimer’s type, frontotemporal dementia or other)

• tumor damage to the brain

• high fever

• a side effect of surgery (post-operative delirium)

• drug, alcohol use

• certain medications taken alone or in combination: against pain, for sleeping, against allergies, against anxiety or depression, against Parkinson’s disease, or against asthma
• some psychiatric illnesses, such as bipolar disorder or schizophrenia, can be accompanied by delirium.

Symptoms of delirium can last for a few hours or several weeks. If the causes are identified and treatable, recovery can be rapid. Note, however, that recovery will depend on the state of physical and mental health of the person affected before he presents with delirium. For example, if the person was already suffering from a severe or chronic illness, they may not fully recover their abilities.

Treatment will depend on the cause of the delirium. Thus, the doctor will conduct a detailed interview consisting of a series of questions about the patient’s medical history, his mental status, and the identification of causes or factors triggering the delirium. He will also do a detailed physical examination to find out the causes of the delirium. To deepen his analysis, the doctor may order blood or urine tests, among others.

Neuroleptic or antidepressant drugs can be used depending on the case.

Hospitalization is sometimes necessary. Psychotherapy can be effective in addition to treat delirium, but also once the crisis has passed, to allow the affected person to regain serenity and a socio-professional life.