Not "just in the head": psychosis triggered by chronic subdural hematoma

Chronic subdural hematoma (cSDH) is a common and increasingly prevalent neurosurgical condition in older adults, typically presenting with headaches, cognitive decline, or focal neurological deficits. Neuropsychiatric manifestations such as confusion, memory impairment, and personality change are well recognized. However, frank psychosis - characterized by hallucinations, delusions, or grossly disorganized behavior - is a rare and underappreciated presentation. When psychosis occurs in older patients, symptoms are frequently misattributed to primary psychiatric or neurodegenerative disorders, leading to delayed diagnosis and treatment. This narrative review examines the relationship between cSDH and psychosis, synthesizing historical and contemporary literature to highlight clinical patterns, mechanisms, and management considerations. Available evidence, largely from case reports and small series, suggests that psychosis due to cSDH most often occurs in older individuals without prior psychiatric history and may present without focal neurological deficits. Symptom resolution following hematoma evacuation supports a causal relationship. Proposed mechanisms include mass effect, intracranial hypertension, cerebral hypoperfusion inflammatory cytokine-mediated cortical dysfunction, and seizure-related phenomena. Management centers on prompt neurosurgical intervention, most commonly burr-hole evacuation, which frequently leads to rapid improvement of psychiatric symptoms. Supportive psychopharmacologic measures may be used transiently but should not obscure neurological assessment. Emerging nonsurgical therapies, including statins and middle meningeal artery embolization, may play adjunctive roles but are not substitutes for urgent decompression. This review emphasizes maintaining a high index of suspicion for cSDH in older patients with new-onset psychosis and the need for timely neuroimaging, as cSDH is a treatable and potentially reversible cause of severe psychiatric symptoms.