Dear Editor,
Psychogenic polydipsia is defined as excessive intake of water in the absence of any physiological stimuli like dehydration or hyperosmolar states. Incidence of the same is estimated at 6–20% in schizophrenic patients and only a few in bipolar patients.[1] Though under-recognized, psychogenic polydipsia may have direct effects on mortality and morbidity.
Psychogenic polydipsia may be due to a hyperdopaminergic state or may also present as a prodromal symptom during mania.[2,3]
A 51-year-old male diagnosed with bipolar disorder 12 years back and on regular treatment with an average of 2–3 manic episodes in a year and similar depressive episodes, presented in a manic episode with symptoms of talkativeness, overfamiliarity and decreased need for sleep for 2 months and was being managed on mood stabilizers, antipsychotics and benzodiazepines, with history of hospitalization due to recurrent hyponatremia in last two months. In investigations to evaluate the cause of hyponatremia, his serum sodium level was found to be 126 mmol/L, while his renal function test/complete blood count/liver function test (RFT/CBC/LFT) were within the normal range. The serum osmolality was around 221.0 mOsm/kg, urinary sodium was 15 mmol/L, and urine osmolality was around 70.0 mOsm/kg. These findings led to the diagnosis of dilutional hyponatremia, indicating psychogenic polydipsia. Tolvaptan was discontinued and managed on fluid restriction and psychiatric management for his manic symptoms. Rapid correction of sodium was avoided to prevent neurological complications. With accurate fluid restriction and psychiatric treatment, manic symptoms decreased and sodium levels increased after 5–6 days of close monitoring.
This case highlights the need for appropriate treatment in patients with hyponatremia and also adds to the limited data available on hyponatremia in patients with bipolar disorder. Diagnosis of psychogenic polydipsia remains under-recognized in patients with mood disorders. Also, this has been associated with the prodrome of mania, but in our patient, it came with the ongoing episode of mania.[3] While the cause of psychogenic polydipsia can be multifactorial, the cause of the same in bipolar patients is attributed to multiple factors. The hyperdopaminergic state in mania can lead to excess fluid intake.[2] Hypothalamic dysfunction may affect the osmoregulatory pathways leading to inappropriate thirst signals.[1] Lastly, behavioral reinforcement may also perpetuate the same.[4]
Psychogenic polydipsia leading to hyponatremia, which in our case was chronic, leading to multiple hospitalizations, can increase the morbidity.[4] The same, coinciding with a manic episode, makes it altogether important to evaluate the cause and comprehensive treatment. Also, the necessity to differentiate psychogenic polydipsia from syndrome of inappropriate antidiuretic hormone secretion (SIADH) holds much importance. As SIADH is treated with a vasopressin receptor antagonist, which, in cases given in patients with psychogenic polydipsia, as in our patient, may increase chances of osmotic demyelination syndrome, a neurological side effect seen due to rapid sodium fluctuations.[5]
Our case highlights that the occurrence of psychogenic polydipsia in manic patients, though uncommon, can lead to complications. Secondly, biochemical evaluation is a must to differentiate SIADH and psychogenic polydipsia. Lastly, inappropriate use of vaptans might lead to deterioration, as in the case of our patient.
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The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published, and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Authors’ contributions
Manuscript preparation, data acquisition HA. Conceptualization and designing, manuscript editing and review. AS, MB. Literature search, Data analysis, manuscript editing and review: YB.
Data availability statement
Data will be made available on reasonable request.
Conflicts of interest
There are no conflicts of interest.
Funding Statement
Nil.
REFERENCES
- 1.Bhatia MS, Goyal A, Saha R, Doval N. Psychogenic Polydipsia - Management Challenges. Shanghai Arch Psychiatry. 2017;29:180–3. doi: 10.11919/j.issn.1002-0829.216106. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Parag S, Espiridion ED. Hyponatremia Presenting with Recurrent Mania. Cureus. 2018;10:e3645. doi: 10.7759/cureus.3645. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Ceylan ME, Ünsalver BÖ, Evrensel A. Polydipsia as a Precursor of Manic Episode in Bipolar Affective Disorder Patients with Alcohol Use Disorder. Clin Psychopharmacol Neurosci. 2018;16:114–7. doi: 10.9758/cpn.2018.16.1.114. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Gonçalves Godinho F, Melo AL, Marques S, Barrocas D. Psychosis-related polydipsia and chronic hyponatremia – A case report. European Psychiatry. 2016;33(S1):S578. [Google Scholar]
- 5.Tandukar S, Sterns RH, Rondon-Berrios H. Osmotic Demyelination Syndrome following Correction of Hyponatremia by ≤10 mEq/L per Day. Kidney360. 2021;2:1415–23. doi: 10.34067/KID.0004402021. [DOI] [PMC free article] [PubMed] [Google Scholar]
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Data Availability Statement
Data will be made available on reasonable request.