King George's Psychosis: A Case Report of Neuroporphyria in an Acute Psychiatric Inpatient Unit

Porphyrias are rare metabolic disorders stemming from impaired heme biosynthesis, with neuroporphyrias comprising a subset characterized by neuropsychiatric symptoms due to toxic intermediary buildup in the nervous system. Here, we explore the case of a 67-year-old man with no previous psychiatric history who was taken to the emergency department for psychiatric symptoms, including delusional speech, grandiosity, irritable mood, and psychomotor agitation. He was involuntarily admitted under the Portuguese Mental Health Act with a provisional diagnosis of mania with psychotic symptoms. Despite initial treatment with valproic acid, clinical deterioration prompted a metabolic workup leading to a diagnosis of acute porphyria. The patient was discharged fully recovered and remained stable during follow-up, relieved after understanding his diagnosis. Although rare, porphyric attacks can be fatal or cause long-term neurological damage. This case underscores the importance of recognizing neuroporphyria, highlighting the need for comprehensive evaluation and timely intervention to mitigate potential adverse outcomes.