Polydipsia as a manifestation of catatonia: Case series

Introduction: Psychogenic polydipsia, a diagnosis of exclusion, is prevalent among patients with psychiatric disorders. Polydipsia has been associated with catatonia without clear causation or directionality. We describe two cases where polydipsia was a sign of catatonia in the form of stereotypy, represented by abnormally frequent motor behavior. Case 1: A 56-year-old male with a history of bipolar I disorder and obsessive-compulsive disorder presented with paranoid delusions, agitation, poor sleep, self-inflicted injury, and hyponatremia related to polydipsia. Symptoms, including polydipsia, rapidly improved with lorazepam. Due to medication nonadherence, two other similar hospitalizations occurred over the next month, each presenting with polydipsia-related hyponatremia as well as other catatonia symptoms. In each of the three episodes of concurrent catatonia and polydipsia, lorazepam as part of the treatment regimen quickly resolved both the psychiatric and metabolic symptoms. Case 2: A 76-year-old female with a history of bipolar I disorder presented with intrusive speech, impulsive behavior, and decreased sleep, alongside hyponatremia related to polydipsia. She also displayed several catatonic symptoms and was treated with lorazepam and paliperidone. Increasing paliperidone dose worsened the catatonia, polydipsia, and hyponatremia while increasing lorazepam resulted in improvement in these symptoms. Discussion: Our patients presented with episodic polydipsia and hyponatremia concurrent with catatonia symptoms. Polydipsia in both cases is a repetitive motor behavior, likely representing a catatonic stereotypy. Our cases illustrate psychogenic polydipsia can sometimes be framed as a catatonic stereotypy, and therefore lorazepam emerges as an option for treatment.