Last reviewed: 16 Sep 2021
Last updated: 16 Oct 2019




  • Schizophrenia
  • Schizoaffective disorder
  • Brief psychotic disorder
  • Schizophreniform disorder
  • Depression with psychotic features
  • Bipolar disorder
  • Delusional disorder
  • Alcohol
  • Withdrawal syndrome
  • Cocaine
  • Cannabis
  • Amfetamines
  • Phencyclidine
  • Inhalants (solvents, aerosols, gases, nitrites)
  • Dextromethorphan
  • Dementia
  • Chronic thiamine deficiency (Korsakoff's psychosis)
  • Acute hepatic porphyria


  • Delusional symptoms in partner of individual with delusional disorder (folie a deux)
  • Organophosphate toxicity
  • Anticholinergics
  • Dopamine agonists
  • Other prescription or over-the-counter medications
  • Heavy metal toxicity
  • Traumatic brain injury
  • Brain tumour
  • Epilepsy
  • Multiple sclerosis
  • Fahr's disease
  • Encephalitis
  • HIV
  • Neurosyphilis
  • Delirium with psychosis
  • Vitamin B12 deficiency
  • Folate deficiency
  • Niacin deficiency
  • Cushing's syndrome
  • Thyroid dysfunction
  • Thymoma
  • Hyperparathyroidism
  • Lupus cerebritis
  • Wilson's disease
  • Lysosomal storage disease
  • Homocystinuria
  • Metachromatic leukodystrophy
  • Klinefelter's syndrome
  • DiGeorge syndrome
  • Prader-Willi syndrome



Adrian Preda, MD

Professor of Clinical Psychiatry

Department of Psychiatry and Human Behavior

University of California, Irvine School of Medicine




AP declares that he has no competing interests.


Dr Adrian Preda would like to gratefully acknowledge Dr Karen A. Graham and Dr Diana O. Perkins, previous contributors to this topic. KAG declares that she has no competing interests. DOP has served as a consultant on antipsychotic medications for Genetech, Janssen, Lundbeck, Otsuka, and Sunovion. The University of North Carolina at Chapel Hill received compensation for research and consulting work by DOP from Genetech, the NIH, Research Triangle Institute, and the State of North Carolina; the university has also been awarded a patent for isolation of pluripotent stem cells from human tissues, with Diana Perkins listed as one of the inventors. DOP has received royalties for the textbook Schizophrenia, published by the American Psychiatric Association Press.

Peer reviewers

Philip McGuire, MBChB, MD, PhD, FRCPsych

Department of Psychiatry

Institute of Psychiatry




PM has been reimbursed by manufacturers of antipsychotic drugs for consultancy and speaking at conferences. PM has received grant funding for research and to support scientific conferences.

Vinod H. Srihari, MD

Assistant Professor of Psychiatry

Yale University School of Medicine

Connecticut Mental Health Center

New Haven



VHS declares that he has no competing interests.

Use of this content is subject to our disclaimer