A Case of Psychogenic Polydipsia with Underlying Stressor

Abstract

Lamotrigine, a new anti-epileptic mood stabilizer, with documented therapeutic benefits for refractory bipolar disorder [1], is reported to enhance clinical improvement in bipolar affective disorder when added to valproate therapy in adults [2]. The present report reveals the clinical efficacy and safety of such combination therapy for the treatment of paediatric bipolar affective disorder.A 71/2-year-old boy, RM, presented with DSM-IV bipolar affective disorder, mixed affective episode. His physical state and blood investigations were unremarkable, but electroencephalogram (EEG) showed generalized epileptiform (spike-waves) activities. He was commenced on sodium valproate 600 mg/day (20 mg/kg/day) along with olanzapine 2.5 mg/day, the latter being started for aggression. Due to lack of clinical response, at 6 weeks, lamotrigine was added to this regimen at a dose of 12.5 mg/day. The lamotrigine dose was gradually increased with 12.5 mg every 2 weeks and at 8 weeks of treatment, while on a dose of 62.5 mg/day, his symptoms remitted completely with no evidence of any adverse effects. Olanzapine was discontinued after 1 month on follow-up, and he remained symptom-free for the next 6 months.The report shows that lamotrigine add-on to sodium valproate therapy facilitated clinical remission and that this combination was well tolerated. The presence of EEG abnormalities could be considered a potential factor favouring clinical improvement with an anti-epileptic mood stabilizer therapy [3]. However, symptomatic remission in this patient, following combination therapy, suggests that the differential pharmacodynamic properties of valproate (GABA enhancer) and lamotrigine (sodium channel stabilizer) [4] could possibly have had a synergistic effect in facilitating clinical remission.

Psychogenic polydipsia

“…The various conditions in which PPD can be seen are (i) Positive symptoms schizophrenic, compulsive behavior and stress reduction. [2369] (ii) PPD can also occur in psychiatric patients in order to reduce the effect of anticholinergic drugs. [10] (iii) It is also suggested that elevated levels of dopamine may be stimulating the thirst center, or the supersenstivity of the dopamine receptor may be responsible for the same as it is usually the chronic schizophrenics with long-term intake of neuroleptics presenting with PPD.…”

“…This could also be due to the stress of broken marriage and childbirth as found by others also. [69]…”

“…[2] Polydipsia in psychiatry patients is seen in patients with chronic schizophrenia with long-term hospitalization. Other psychiatric diagnoses have rarely been associated with polydipsia, such as affective disorders, psychosis with onset during childhood, mental retardation and personality disorders, tension/anxiety[236] psychogenic or primary polydipsia, affects about 6-20% of the psychiatric patients. [78] There are no cases we believe in the Indian psychiatry scene of the same.…”