Introduction. Hyponatremia is an important part of psychiatric practice. In order to analyze its causes and symptoms, the literature on hyponatremia in psychiatric patients has been reviewed. The work has been divided into two separate manuscripts. In the first one the authors discuss the syndrome of inappropriate antidiuretic hormone secretion (SIADH) and hyponatremia occurring with the use of psychotropic drugs (antidepressants, antipsychotics, normotimics), while the second paper discusses research on psychogenic polydipsia. The causes of hyponatremia in patients treated in psychiatric wards include: water intoxication associated with polydipsia, somatic comorbidities, side effect of internal medicine and psychiatric drugs. The most common mechanism leading in these cases to hyponatremia is the syndrome of inappropriate secretion of vasopressin (SIADH). The SIADH syndrome is a group of symptoms, first described in 1967 by Schwartz and Bartter in The American Journal of Medicine, which results from the hypersecretion of antidiuretic hormone, also called vasopressin, which causes patients to develop normovolemic hyponatremia. The phenomenon of drug-induced hyponatremia in psychiatric practice is generally observed with the use of antidepressants, antipsychotics and anti-epileptic drugs (used in psychiatry as normotimic drugs).Aim and method. The first manuscript includes a review of literature on the syndrome of inappropriate secretion of vasopressin (SIADH) and hyponatremia occurring after the use of psychotropic drugs, and is divided into two subsections: 1. The syndrome of inappropriate secretion of vasopressin (SIADH), 2. Hyponatremia and psychotropic drugs (antidepressants, antipsychotics, normotimics).Conclusion. In the view of the reviewed literature it is extremely important to control the natremia level during pharmacotherapy using the above mentioned drugs, especially in the initial period of therapy.

Objective. The study is the second part of the literature review on hyponatremia in patients with diagnosed mental disorders. This article focuses on psychogenic polydipsia as, along with the SIADH, one of the two most common causes of hyponatremia in the mentioned group of patients.Method: The literature review was based on searching the Medline, the Google Scholar and the Ebsco databases in Polish and English by entering the following phrases: psychogenic polydipsia, the psychosis -intermittent hyponatremia -polydipsia syndrome, water intoxication.Discussion: Psychogenic polydipsia occurs in up to 25% of patients treated for mental disorders. It most frequently concerns patients with schizophrenia. 30% of patients with psychogenic polydipsia suffer from hyponatremia with or without symptoms of water intoxication. In the etiology of psychogenic polydipsia, the influence of dopaminergic and noradrenergic neurotransmission has been considered, as well as angiotensin, which is claimed to have dipsogenic properties. In order to reduce the severity of the disorder, attempts have been made to administer the following groups of medications: β-blockers, opioid receptor antagonists, angiotensin convertase inhibitors and angiotensin receptor antagonists. Other methods include replacing classic antipsychotic drugs with clozapine. There are also reports of a reduced severity of polydipsia with hyponatremia after introducing risperidone and olanzapine. Preventing episodes of water intoxication in patients with psychogenic polydipsia requires the monitoring of their body weight and a suitable reduction of fluid intake by them.Results: Mentally ill patients, especially those with chronic schizophrenia, should be monitored for psychogenic polydipsia and the concomitant hyponatremia. Keywords: psychogenic polydipsia, hyponatremia, water intoxication StreszczenieCel. Praca jest drugą częścią przeglądu literatury na temat hiponatremii u pacjentów z rozpoznaniem zaburzeń psychicznych. W niniejszym artykule skoncentrujemy uwagę na polidypsji psychogennej jako jednej z dwóch, obok zespołu SIADH, najczęstszych przyczyn hiponatremii w tej grupie chorych.Metoda: Przeglądu literatury dokonaliśmy przeszukując bazy danych Medline, Google Scholar i Ebsco w języku polskim i angielskim, wpisując hasła: polidypsja psychogenna, zespół psychoza -hiponatremia przerywana -polidypsja, zatrucie wodne.Omówienie: Polidypsja psychogenna występuje nawet u 25% pacjentów leczonych z powodu zaburzeń psychicznych. Najczęściej dotyczy pacjentów chorych na schizofrenię. U 30 % pacjentów z polidypsją psychogenną występuje hiponatremia z objawami lub bez objawów zatrucia wodnego. W etiologii polidypsji psychogennej rozważano znaczenie neuroprzekaźnictwa dopaminergicznego, noradrenergicznego, jak również angiotensyny, której przypisuje się właściwości dipsogenne. W celu zmniejszenia jej nasilenia podejmowano próby stosowania takich grup leków jak: β-blokery, antagoniści receptorów opioidowych, inhibitory konwertazy angiotensyny czy antagoniści receptoró...