Polydipsia is excessive thirst/compulsive water drinking. Primary polydipsia is, as I understand it, a thirst with a physical source, such as diabetes, whereas psychogenic polydipsia has a mental cause, most often schizophrenia. Here are some links with information/case studies:
* excessive loss of water and salt (as in profuse sweating)
* a recent salty, spicy meal
* diabetes mellitus or diabetes insipidus
* drugs including anticholinergics, demeclocycline, diuretics, phenothiazines
* bleeding enough to cause a significant decrease in blood volume
* loss of body fluids from the bloodstream to the tissues
- can occur with conditions such as severe infections (sepsis) and with burns
* psychogenic polydipsia
A 42-year-old man presented an acute episode of psychogenic polydipsia lasting 5 days in which he drank up to 6 l of fluids daily. The episode was observed 24 hours after his admission to a general hospital...
At the end of the investigations, all possible organic factors were excluded. We concluded that this was an episode of psychogenic polydipsia, without water intoxication or sub-intoxication. The patient also fulfilled the DSM-IV criteria for Major Depressive Disorder (DSM-IV 296.22) with symptoms of depressive mood, lack of interest, asthenia, inability to concentrate, guilt feelings, repetitive suicidal thoughts and also social and professional dysfunction. This depressive disorder was stress-related due to overwork. All the symptoms of polydipsia regressed after a brief period of strict fluid restriction, an anxiety-relieving treatment by slow intravenous administration of benzodiazepines and supportive psychotherapy. The patient explained that he felt better after drinking water. To his mind, water was synonymous with life and when his tropical plants were withering, it was necessary to give them water.
Psychogenic polydipsia is an uncommon clinical disorder characterized by excessive water-drinking in the absence of a physiologic stimulus to drink. The excessive water-drinking is well tolerated unless hyponatraemia supervenes (1). The level of hyponatraemia used in one study was below 130 mmol/L (2). Classically this disorder has been described in hospitalised schizophrenics. Also it may occur in children, as a symptom of emotional difficulties or as an isolated phenomenon in a child who simply enjoys drinking.