Antiphospholipid syndrome

Page most recently updated 7 September 2026

This page focuses on the reported psychiatric associations, which may be the initial presenting manifestation, and on other clinical features that may assist the psychiatrist or primary care physician in identifying the underlying diagnosis, considered through the lenses of the diagnostic lenses framework.

Antiphospholipid syndrome is an immune-mediated disorder characterized by an increased tendency to thrombosis and pregnancy complications, resulting in multisystemic effects.

It can present with psychiatric features such as cognitive impairment, mood symptoms, behavioural change, anxiety, and, less commonly, psychosis, particularly in association with neurological or cerebrovascular involvement.

Other characteristic features include arterial and venous thrombotic events, particularly ischaemic stroke and transient ischaemic attacks, as well as seizures, migraine, chorea, cognitive dysfunction, and other neurological manifestations. Obstetric morbidity is another defining clinical feature, including recurrent pregnancy loss, fetal death, severe pre-eclampsia, and placental insufficiency.

From a multisystemic lens perspective, clinical features in other body systems include (but are not limited to):

  • Cardiovascular: cardiac valvular abnormalities, particularly mitral or aortic valve thickening, vegetations, and dysfunction; arterial thrombosis may cause myocardial infarction or other acute coronary syndromes.

  • Respiratory: pulmonary embolism and, in some patients, pulmonary hypertension may occur as consequences of thromboembolic disease.

  • Renal/electrolytes: renal involvement may manifest as hypertension, proteinuria, haematuria, and renal impairment due to antiphospholipid-associated nephropathy or renal vascular thrombosis.

  • Hematologic: thrombocytopenia is a common non-criteria manifestation; haemolytic anaemia may also occur.

  • Dermatologic: livedo reticularis is a characteristic cutaneous manifestation; skin ulcers and digital ischaemic lesions may also occur.

Early diagnosis is important to identify patients at risk of recurrent or potentially life-threatening thrombosis and pregnancy complications, enable appropriate antithrombotic treatment, recognize multisystem involvement, and reduce the risk of irreversible neurological and other organ damage.

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.