Psychogenic Polydipsia Presenting as Recurrent Hyponatremic Seizures in a Patient With Schizoaffective Disorder

Psychogenic polydipsia is a rare but potentially fatal condition characterized by excessive water consumption leading to dilutional hyponatremia and neurological complications. It is most frequently seen in patients with chronic psychotic disorders such as schizophrenia and schizoaffective disorder. We present a 42-year-old man with a 22-year history of schizoaffective disorder who developed recurrent generalized tonic-clonic seizures and confusion. Initial evaluation revealed severe hyponatremia, but the cause could not be identified. He was admitted to an intensive care unit and treated with hypertonic saline and antiepileptic medication. After stabilization and discharge, he experienced difficulty in sleeping and hallucinatory behavior and was subsequently readmitted under psychiatric care. During routine workup, laboratory investigations confirmed hyponatremia again, which was then further investigated for causes and found. The patient had hypotonic hyponatremia with low serum osmolality and inappropriately dilute urine, consistent with psychogenic polydipsia. Endocrine and systemic causes, including diabetes insipidus, adrenal insufficiency, and hypothyroidism, were excluded. Drug history was taken in detail to rule out any drugs causing hyponatremia and substance abuse was ruled out as well. The patient was observed during his ward stay and it was found that he would drink excessive amounts of water, exceeding 15 liters daily, including water from storage tanks and washing areas. Management focused on cautious correction of serum sodium to prevent osmotic demyelination, positive and negative reinforcement for fluid restriction, seizure prophylaxis, and optimization of psychiatric treatment. He underwent nine sessions of bilateral electroconvulsive therapy for refractory affective and psychotic symptoms and participated in behavioral modification sessions aimed at reducing water-seeking behavior. Sodium levels normalized within 10 days, and no further seizures occurred. At the six-month follow-up, the patient remained stable under supervised care, compliant with medication, and maintained a restricted fluid intake below two liters daily. This case underscores the importance of early recognition of psychogenic polydipsia as a reversible cause of recurrent seizures and hyponatremia in psychiatric populations. Vigilant monitoring of fluid intake, interdisciplinary management, and behavioral intervention are crucial to achieving sustained recovery and preventing recurrence.