This page provides a differential diagnosis of multisystemic conditions involving the above two organ systems that may also be associated with psychosis.
Each condition listed below is linked to a dedicated page within this resource. These pages describe other potential multisystemic manifestations and psychiatric associations of each condition, allowing the information to be explored from both multisystemic and psychiatric perspectives.
Of note, to optimize clinical utility, the list does not include conditions in which psychosis occurs only in the context of delirium. The list includes only conditions in which psychosis may occur in the setting of intact attention and orientation. Presentations in which psychosis occurs exclusively in the context of delirium fall outside the intended scope of this psychiatric differential and are appropriately considered within the broader medical assessment and management of delirium.
Multisystemic conditions with
cardiovascular and gastrointestinal involvement
Page most recently updated 7 September 2026
Image credit: © 2026 Islam Hassan. All rights reserved.
● Intrinsic
▪ Immune-mediated
◦ Autoimmune encephalitis with multisystemic involvement
Anti-NMDA receptor encephalitis ➚
◦ Connective tissue diseases
Systemic lupus erythematosus ➚
Mixed connective tissue disease ➚
◦ Systemic vasculitides
Eosinophilic granulomatosis with polyangiitis (formerly Churg–Strauss syndrome) ➚
◦ Other immune-mediated disorders
Idiopathic hypereosinophilic syndrome ➚
▪ Endocrine
◦ Hyperparathyroidism (and hypercalcemia from non-endocrine causes) ➚
▪ Genetic
◦ Trisomy 21 (Down syndrome) ➚
◦ Neurometabolic disorders
Acute hepatic porphyrias (e.g., acute intermittent porphyria) ➚
X-linked adrenoleukodystrophy ➚
Cerebrotendinous xanthomatosis ➚
▪ Neoplastic
▪ Other
◦ Posterior reversible encephalopathy syndrome (PRES) ➚
● Extrinsic
▪ Toxic and deficiency states
◦ Thiamine (vitamin B1) deficiency ➚
◦ Severe malnutrition/starvation ➚
▪ Infectious
◦ Bacterial
Selected references and further reading — Multisystemic lens
Cardinal RN, Bullmore ET. The diagnosis of psychosis. Cambridge: Cambridge University Press; 2011.
Sachdev PS, Keshavan MS, editors. Secondary schizophrenia. Cambridge: Cambridge University Press; 2010.
Levenson JL, editor. The American Psychiatric Association Publishing textbook of psychosomatic medicine and consultation-liaison psychiatry. 3rd ed. Washington (DC): American Psychiatric Association Publishing; 2019.
Stern TA, Beach SR, Smith FA, Freudenreich O, Vranceau AM, Fava M, editors. Massachusetts General Hospital handbook of general hospital psychiatry. 8th ed. Philadelphia: Elsevier; 2025.
Arciniegas DB, Yudofsky SC, Hales RE, editors. The American Psychiatric Association Publishing textbook of neuropsychiatry and clinical neurosciences. 6th ed. Washington (DC): American Psychiatric Association Publishing; 2018.
Agrawal N, Faruqui R, Bodani M, editors. Oxford textbook of neuropsychiatry. Oxford: Oxford University Press; 2020.
Boland R, Verduin M, editors. Kaplan and Sadock's comprehensive textbook of psychiatry. 11th ed. Philadelphia: Wolters Kluwer; 2024.
Loscalzo J, Fauci AS, Kasper DL, Hauser SL, Longo DL, Jameson JL, editors. Harrison's principles of internal medicine. 22nd ed. New York: McGraw Hill; 2025.