There are a very large number of toxins that can lead to hallucinations and/or delirium.

• Withdrawal states
• Anticholinergic syndrome
• Serotonergic syndrome
• Dopaminergic drugs
• Illicit drugs
• Differentiating features

A psychotomimetic reaction, with apparent visual or auditory hallucinations, delirium and heightened or only slightly decreased level of consciousness, is most commonly due to:

• Alcohol withdrawal
• Sedative drug withdrawal

• Anticholinergic drugs
• Antihistamines
• Tricyclic antidepressants (TCAs)
• Low potency neuroleptics

• Selective serotonin reuptake inhibitors (SSRIs)
• Monoamine oxidase inhibitors (MAO inhibitors)
• Tricyclic antidepressants (TCAs)

• Bromocriptine
• L-dopa

• Amphetamines
• Cocaine
• MDMA(ecstasy)
• Illicit hallucinogens (LSD, mescaline)
• Hallucinogenic mushrooms
• Hallucinogenic plants (mostly anticholinergic)
• Marijuana
• Alcohol intoxication

In addition, a large number of drugs that impair consciousness may lead to delirium usually without significant hallucinosis. These drugs are discussed under drugs leading to coma.

Features that help to differentiate between these drugs are:

• Response to Painful Stimuli
• Type of Hallucinations
• Hyperthermia
• Response to Antagonists
• Pupil Size and Reaction
• Myoclonic Jerking or Hyperreflexia
• Nystagmus
• Heart Rate
• Bowel Sounds
• ECG Changes
• Response To Antagonists
• Electrolytes and Blood Glucose
• Blood Concentrations

See also delirium treatment.