Terminology
In diagnosis, primary polydipsia is usually categorised as:

Psychogenic (PPD) – caused by underlying psychiatric symptoms, including those caused by psychoses and rarely by affective disorders
Non-psychogenic – another non-psychological cause, including idiopathic (unknown cause)The terms primary polydipsia and psychogenic polydipsia are sometimes incorrectly used interchangeably – to be considered psychogenic, the patient needs to have some other psychiatric symptoms, such as delusions involving fluid intake or other unusual behaviours. Primary polydipsia may have physiological causes, such as autoimmune hepatitis. Since primary polydipsia is a diagnosis of exclusion, the diagnosis may be made for patients who have medically unexplained excessive thirst, and this is sometimes incorrectly referred to as psychogenic rather than primary polydipsia. Non-psychogenic
Although primary polydipsia is usually categorised as psychogenic, there are some rare non-psychogenic causes. An example is polydipsia found in patients with autoimmune chronic hepatitis with severely elevated globulin levels. Evidence for the thirst being non-psychogenic is gained from the fact that it disappears after treatment of the underlying disease. Non-human animals
Psychogenic polydipsia is also observed in some non-human patients, such as in rats and cats. See also
Water intoxication
Fluid deprivation test

References
Further reading
Siegler EL, Tamres D, Berlin JA, Allen-Taylor L, Strom BL (May 1995). "Risk factors for the development of hyponatremia in psychiatric inpatients". Archives of Internal Medicine. 155 (9): 953–957. doi:10.1001/archinte.1995.00430090099011. PMID 7726704. Mauri MC, Volonteri LS, Fiorentini A, Dieci M, Righini A, Vita A (July 2002). "Efficacy of clozapine in a non-schizophrenic patient with psychogenic polydipsia and central pontine myelinolysis". Human Psychopharmacology. 17 (5): 253–255. doi:10.1002/hup.407. PMID 12404683. S2CID 21589725.
Calcium deficiency may refer to:

Calcium deficiency, a plant disorder that can be caused by insufficient calcium in the growing medium, but is more frequently a product of low transpiration of the whole plant or more commonly the affected tissue
Hypocalcaemia, the presence of low serum calcium levels in the blood