Primary polydipsia 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. Psychogenic polydipsia is also observed in some non-human patients, such as in rats. Primary polydipsia Primary polydipsia is a form of polydipsia characterised by excessive fluid intake in the absence of physiological stimuli to drink. This includes psychogenic polydipsia (PPD – not to be confused with postpartum depression), which is caused by psychiatric disorders, often schizophrenia, and often accompanied by the
Polydipsia in birds chickens (broilers), subjected routinely to chronic food restriction, show increased drinking after a single daily meal along with other oral stereotypies. Expression of these activities is correlated positively with the level of restriction imposed, and is thought to be controlled mainly by central dopaminergic mechanisms. Under experimental conditions where birds receive reinforcements on a strict schedule, for example receiving one pellet of food each minute often indicated by a tone or other stimulus, the birds may develop polydipsia. Under these conditions it is called schedule induced polydipsia or sometimes, adjunctive drinking. Some strains of hens are polydipsic, drinking almost twice