Description

Disorder of brain function characterized illogical, bizarre, or delusional beliefs, abnormal perceptions, and disorganization of emotions, thought, and behavior

Etiology

• Primary psychotic disorders:
  • Schizophrenia: >6 mo 2 of the following: Hallucinations, delusions, negative symptoms, disorganized thought, disorganized behavior
  • Brief psychotic disorder if symptoms <1 mo, schizophreniform disorder if symptoms 1–6 mo
  • Schizoaffective disorder: Prominent mood symptoms concurrent with psychotic decompensations
  • Delusional disorder: Presence of rigid delusion without other symptoms of psychosis
• Mood disorders:
  • Mania with psychotic features
  • Depression with psychotic features
• Psychiatric mimics of psychosis (not true psychotic disorders but may resemble them):
  • Posttraumatic stress disorder: May involve strong referential thinking and fear of being in danger out of proportion with objective reality
  • Borderline personality disorder: May involve strong referential thinking and related affective lability
  • Obsessive-compulsive disorder: Nature of obsessions may be so illogical and rigid as to seem psychotic
  • Neurodevelopmental disorders: Those with autism or intellectual disability may have odd/bizarre/unrealistic beliefs or experience internal thoughts as “voices”

• Neurologic disease:
  • Delirium (prominent confusion, inattentiveness, waxing/waning level of consciousness; may include perceptual disturbances and illogical/delusional thinking)
  • Head injury
  • Dementia (hallucinations and delusions may occur in any dementia including Alzheimer, Lewy body, frontotemporal)
  • Cerebrovascular accident (acute or chronic)
  • Seizures (inter-/postictal)
  • Space-occupying lesions (neoplasm, abscesses, cysts)
  • Hydrocephalus
  • Demyelinating diseases (multiple sclerosis)
  • Neuropsychiatric disorders (Parkinson disease, Huntington disease, Wilson disease)
  • Prion disease
• Infectious disease:
  • Meningitis/encephalitis (bacterial, viral, or fungal)
  • HIV
  • Tertiary syphilis
  • Tertiary Lyme disease
• Metabolic:
  • Intoxication (psychostimulants, hallucinogens, ketamine, phencyclidine, cannabinoids, MDMA, dextromethorphan)
  • Adverse medication effect (cyclosporine, cycloserine, corticosteroids, fluoroquinolones, amantadine, levodopa, pramipexole, levetiracetam)
  • Hypercalcemia
  • B₁₂ deficiency
  • Heavy metal poisoning (arsenic, mercury)
  • Porphyria
• Endocrine:
  • Thyroid disease
  • Cushing syndrome
  • Adrenal insufficiency
• Autoimmune disease:
  • Lupus cerebritis (usually accompanies neurologic symptoms such as seizure)
  • Autoimmune encephalitis (i.e., anti-NMDA)
  • Paraneoplastic syndrome
• Toxins:
  • Heavy metals
  • Organophosphates
  • Carbon monoxide