Psychogenic polydipsia

Last reviewed: 24 Aug 2022

Last updated: 10 Aug 2022

Psychogenic polydipsia is commonly encountered in patients with psychiatric disorders, particularly in those with schizophrenia.

Patients present with water-seeking and excessive drinking, sometimes accompanied by hyponatraemia and water intoxication.

Neuropsychiatric manifestations of hyponatraemia include headache, nausea, cramping, hyporeflexia, dysarthric speech, lethargy, confusion, seizures, and delirium. Coma and sudden death can ensue.

Complications of psychogenic polydipsia include incontinence and enuresis, bladder dilation and hydronephrosis, renal and congestive heart failure, and osteoporosis and associated pathological fractures.

Diagnosis is one of exclusion. Other medical causes of polydipsia, polyuria, and/or hyponatraemia need to be ruled out.

Management includes fluid restriction and behavioural and pharmacological therapy. Serum sodium should be monitored vigilantly and frequently with judicious use of hypertonic saline to treat symptomatic or severe hyponatraemia.

Definition

Polydipsia is excessive or abnormal thirst, accompanied by intake of excessive quantities of water or fluid. Psychogenic polydipsia (PPD), also known as primary polydipsia, is characterised by excessive volitional water intake and is often seen in patients with psychiatric disorders and/or neurodevelopmental disorders. There may be no physical effects, but hyponatraemia can occur.

History and exam

Key diagnostic factors

presence of risk factors
water-seeking and drinking

More key diagnostic factors

Other diagnostic factors

polyuria
headache
nausea or vomiting
lethargy or confusion
seizures, delirium, or coma

Other diagnostic factors

Risk factors

psychiatric disorders
neurodevelopmental disorders
smoking

More risk factors

Diagnostic investigations

1st investigations to order

plasma osmolality
urine osmolality
urine sodium
serum sodium
24-hour urine volume
urinalysis
serum urea
water restriction test

More 1st investigations to order

Investigations to consider

vasopressin test
plasma antidiuretic hormone

More investigations to consider

Treatment algorithm

ACUTE

severe hyponatraemia (<125 mmol/L [<125 mEq/L]) or with neurological symptoms

hyponatraemia (125-130 mmol/L [125-130 mEq/L]) or with GI symptoms

ONGOING

chronic polydipsia

Contributors

Authors

Shilpa Srinivasan, MD, DFAPA, DFAAGP

Vice Chair, Medical Staff Affairs, Behavioral Health Midlands, Prisma Health

Professor of Clinical Psychiatry

Program Director: Geriatric Psychiatry Fellowship

Director: Psychiatry Acting Internship and M4 Clerkship

Department of Neuropsychiatry and Behavioral Science

Prisma Health - University of South Carolina School of Medicine Columbia

Columbia

Disclosures

SS is a board member of the American Association for Geriatric Psychiatry and serves on the Geriatric Psychiatry Exam Committee for the American Board of Psychiatry and Neurology.

Meera Narasimhan, MD, DFAPA

Professor and Chair

Department of Neuropsychiatry and Behavioral Science

Senior Medical Director

Prisma Health

Special Advisor to University of South Carolina President

Health Innovations and Economic Development

University of South Carolina School of Medicine Columbia

Columbia

Disclosures

MN is a member of an advisory board for Alkermes.

Acknowledgements

Dr Shilpa Srinivasan and Dr Meera Narasimhan would like to gratefully acknowledge Dr Emily Williams and Dr Brian Dundas, previous contributors to this topic.

Disclosures

EW declares that she has no competing interests. BD is an author of one of the references for this topic.

Peer reviewers

Pieter Joost van Wattum, MD, MA

Assistant Clinical Professor of Child Psychiatry

Yale School of Medicine

Medical Director of Psychiatry

Clifford W. Beers Guidance Clinic

New Haven

Disclosures

PJvW declares that he has no competing interests.

Branimir Margetić, MD

Neuropsychiatric Hospital "Dr Ivan Barbot"

Popovaca

Croatia

Disclosures

BM is an author of a reference cited in this topic.

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Psychogenic polydipsia

Summary

Definition

History and exam

Key diagnostic factors

Other diagnostic factors

Risk factors

Diagnostic investigations

1st investigations to order

Investigations to consider

Treatment algorithm

severe hyponatraemia (<125 mmol/L [<125 mEq/L]) or with neurological symptoms

hyponatraemia (125-130 mmol/L [125-130 mEq/L]) or with GI symptoms

chronic polydipsia

Contributors

Authors

Shilpa Srinivasan, MD, DFAPA, DFAAGP

Disclosures

Meera Narasimhan, MD, DFAPA

Disclosures

Acknowledgements

Disclosures

Peer reviewers

Pieter Joost van Wattum, MD, MA

Disclosures

Branimir Margetić, MD

Disclosures

Differentials

Patient leaflets

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