Cellular dehydration acutely degrades mood mainly in women: a counterbalanced, crossover trial

Br J Nutr. 2021 May 28;125(10):1092-1100. doi: 10.1017/S0007114520003475. Epub 2020 Oct 20.


It is unclear if mild-to-moderate dehydration independently affects mood without confounders like heat exposure or exercise. This study examined the acute effect of cellular dehydration on mood. Forty-nine adults (55 % female, age 39 (sd 8) years) were assigned to counterbalanced, crossover trials. Intracellular dehydration was induced with 2-h (0·1 ml/kg per min) 3 % hypertonic saline (HYPER) infusion or 0·9 % isotonic saline (ISO) as a control. Plasma osmolality increased in HYPER (pre 285 (sd 3), post 305 (sd 4) mmol/kg; P < 0·05) but remained unchanged in ISO (pre 285 (sd 3), post 288 (sd 3) mmol/kg; P > 0·05). Mood was assessed with the short version of the Profile of Mood States Questionnaire (POMS). The POMS sub-scale (confusion-bewilderment, depression-dejection, fatigue-inertia) increased in HYPER compared with ISO (P < 0·05). Total mood disturbance score (TMD) assessed by POMS increased from 10·3 (sd 0·9) to 16·6 (sd 1·7) in HYPER (P < 0·01), but not in ISO (P > 0·05). When TMD was stratified by sex, the increase in the HYPER trial was significant in females (P < 0·01) but not in males (P > 0·05). Following infusion, thirst and copeptin (surrogate for vasopressin) were also higher in females than in males (21·3 (sd 2·0), 14·1 (sd 1·4) pmol/l; P < 0·01) during HYPER. In conclusion, cellular dehydration acutely degraded specific aspects of mood mainly in women. The mechanisms underlying sex differences may be related to elevated thirst and vasopressin.

Keywords: Copeptin; Osmotic stimulation; Thirst; Underhydation; Vasopressin.

Publication types

  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Affect / physiology*
  • Cross-Over Studies
  • Dehydration / chemically induced*
  • Dehydration / psychology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Saline Solution / administration & dosage*
  • Saline Solution, Hypertonic / administration & dosage*


  • Saline Solution
  • Saline Solution, Hypertonic