Psychogenic Polydipsia in a Patient with Alcohol-induced Dementia – a Case Study

Authors: Dr Gabriel J. Ellul, Dr Christopher Rolé, Dr Claire Axiak and Dr. Joseph F. Spiteri

Aims and Hypothesis: To present an academically interesting and clinically challenging case of a man presenting with severe hyponatraemia in an acute medical setting, secondary to psychogenic polydipsia, in the context of dementia and a history of alcohol dependence.

Background: Psychogenic polydipsia involves the volitional ingestion of copious amounts of fluid. It is a diagnosis of exclusion and is distinct from polydipsia secondary to abnormalities in antidiuretic hormone secretion or sensitivity. Psychogenic polydipsia may have serious detrimental sequelae, particularly through physiological disruptions in fluid homeostasis, serum osmolality and electrolyte imbalances. It is difficult to treat and given its rare prevalence, academic literature on the subject is still sparse.

Methods: A case of psychogenic polydipsia was referred for psychiatric consultation, after the medical team noted recurrent episodes of hyponatraemia. The case was managed through a multidisciplinary approach, details of which were subsequently compiled and formulated into a case report.

Results: The case involved a 64 year old gentleman, with recurrent readmissions into acute medical care following repeated episodes of hyponatraemia, with subsequent medical sequelae, including seizures and acute confusional states. Concerns were raised by the medical staff who reported an excessive ingestion of fluids, at times indiscriminately from unhygienic sources, and necessitating twenty-four hour close supervision. History included previous alcohol dependence, the remission of which led to an intractable compulsion to drink water, at times ingesting up to ten litres per day. This was exacerbated by the patient’s underlying cognitive decline. Multiple treatment strategies were attempted, with limited response.

Conclusions: This case highlights the morbidity associated with psychogenic polydipsia, along with its guarded prognosis, particularly due to its non-responsiveness to multiple treatment strategies. It also potentially highlights a transformation in the compulsive drinking habit in a previously alcohol-dependent man with worsening cognitive decline, where salience to alcohol was gradually altered to the insatiable ingestion of water.

No financial interests to declare