Circannual pattern of hypothalamic–pituitary–thyroid (HPT) function and mood during extended antarctic residence

Palinkas, Lawrence A.; Reed, H. L.; Reedy, Kathleen R.; Do, Nhan; Case, H. Samuel; Finney, Nancy S.

doi:10.1016/s0306-4530(00)00064-0

Cited by 48 publications

(47 citation statements)

References 32 publications

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“…This is also in agreement with previous studies in the Antarctic (35), and may indicate a pattern of cold acclimation where the initial increase in catecholamines in response to cold exposure eventually returns to baseline (36,37). Patterns of mood and cognitive performance in this study were consistent with some (38,39), documenting an absence of significant decrements of cognitive performance and a seasonal pattern of decrements in mood (21,40,41). The comparison to placebo with effect of treatment and season shows for the first time in our review that tyrosine intervention results in higher fT 3 and lower serum TSH in winter compared with placebo but not different that the combined T 4 -T 3 supplement.…”

Section: Discussionsupporting

confidence: 81%

“…An 11% decline in performance on a computerized matchingto-sample test cognition was reversed with a daily supplement of thyroxine (64 nmol/d (50 ug). The change in accuracy on the matchingto-sample cognitive performance task was correlated with the change in FT 4 (p<0.01), and increases in serum TSH preceded worsening Profile of Mood State scores in depression, tension, anger, lack of vigour and total mood disturbance (p<0.001) during the austral winter (Feb.-Aug.) (6,21). Thyroxine supplementation also resulted in significant improvements in self-reported measures of fatigue and confusion.…”

Section: Introductionmentioning

confidence: 81%

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Psychoneuroendocrine effects of combined thyroxine and triiodothyronine versus tyrosine during prolonged Antarctic residence

Palinkas

Reedy

Smith

et al. 2007

International Journal of Circumpolar Health

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Objectives. We previously reported that cognitive function improves with thyroxine and that there is a circannual pattern to mood and human TSH during Antarctic residence. To extend these findings, we examined the effects of tyrosine and a combined levothyroxine/ liothyronine supplement in euthyroid men and women who spent the austral summer (n=43) and/or winter (n=42) in Antarctica. Study Design. Randomized, placebo-controlled, clinical trial. Methods. Subjects were randomized to receive the following each day for 91.6±3.2 days in summer and/or 138.0± 3.2 days in winter: (1) 12g tyrosine mixed in 113g applesauce; (2) 50ug of levothyroxine and 12.5ug of liothyronine (T4-T3 Supplement); or (3) placebo. Cognitive performance and mood were assessed using the Automatic Neuropsychological Assessment Metric -Isolated and Confined Environments. Effectiveness of thyroid supplement and tyrosine in Antarctica Results. With placebo in summer, mood did not change while TSH decreased by 28%; in winter, there was a 136% degradation in mood (p<0.01) and TSH increased by 18%. With combined T4-T3 supplement, there was a 51% degradation in mood in summer compared with placebo (p<0.05) and TSH decreased by 57%; in winter there was a 135% degradation in mood while TSH was reduced by 26% (p<0.05). Tyrosine use in summer was associated with no change in mood and a 30% decline in TSH, while in winter there was a 47% improvement in mood and TSH decreased by 28% along with a 6% increase in fT3 (p<0.05). Conclusions. Administration of tyrosine leads to a significant reduction in serum TSH and improvement in mood in winter compared with placebo, while the combined T4-T3 supplement leads to a worsening of mood in summer and no improvement in winter. There appears to be a seasonal influence on the psychological response to interventions and the relationship to changes in TSH reductions. (Int J Circumpolar Health 2007; 66(5):401-417)

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Section: Discussionsupporting

confidence: 81%

Section: Introductionmentioning

confidence: 81%

Psychoneuroendocrine effects of combined thyroxine and triiodothyronine versus tyrosine during prolonged Antarctic residence

Palinkas

Reedy

Smith

et al. 2007

International Journal of Circumpolar Health

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“…In some studies, negative mood has been associated with increases in physical symptoms (1)(2)(3)9,12), thus having potential implications for readiness for duty. For example, one study reported that POMS tension and fatigue were positively associated with a number of physical health symptoms in Navy personnel engaged in Persian Gulf operations (6).…”

Section: Introductionmentioning

confidence: 99%

“…Several studies have documented negative mood in military and quasi-military populations undergoing stressful experiences involving rigorous training and challenging environments (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11). For example, in one study, mood in army soldiers, as measured by the Profile of Mood States (POMS), was assessed shortly after beginning and immediately after completing a maximal effort 20-km road march while carrying a 40-kg load.…”

Section: Introductionmentioning

confidence: 99%

Negative mood endures after completion of high-altitude military training

Bardwell

Ensign

Mills

2005

Annals of Behavioral Medicine

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“…Frequently, studies report a sample size less than 20 (e.g. Palinkas et al 2001;Reed et al 2001;Xu et al 2003) or less than 10 (e.g. Corbett et al 2012;Leon and Scheib 2007).…”

Section: Methodsmentioning

confidence: 99%

Well-Being at the Polish Polar Station, Svalbard: Adaptation to Extreme Environments

Temp

Lee

Bak

2017

The Interconnected Arctic — UArctic Congress 2016

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While the psychological well-being of Antarctic crews has been investigated previously, Arctic crews have received little attention. Antarctic stressors include the permanent darkness of polar night, cramped quarters and harsh weather conditions which demand that the crews work together to survive. These stressors are also present for Arctic crews with the addition of dangerous polar bears. In this study, these psychological stressors were explored at the Polish Polar Station, Svalbard. Nine crew members three of whom were women, took part in the study. They filled in the Profile of Mood States (POMS) and the Symptom Checklist 90-Revised (SCL-90-R) after their arrival, at equinox, during polar night, in spring and during the midnight sun. Depression and hostility were highest in the spring following the isolation of polar night. Vigor reached its lowest point in spring and remained low until mission completion. Confusion continued to decline throughout the mission. The Polish crew adapted by monitoring their feelings to work together and ensure survival. Up until and during the polar night, negative feelings were low. Following the isolation period, depression and hostility increased while vigor declined. This suggests adaptation paradigm wherein the participants stopped to monitor their own feelings as closely after the polar night.

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Circannual pattern of hypothalamic–pituitary–thyroid (HPT) function and mood during extended antarctic residence

Cited by 48 publications

References 32 publications

Psychoneuroendocrine effects of combined thyroxine and triiodothyronine versus tyrosine during prolonged Antarctic residence

Psychoneuroendocrine effects of combined thyroxine and triiodothyronine versus tyrosine during prolonged Antarctic residence

Negative mood endures after completion of high-altitude military training

Well-Being at the Polish Polar Station, Svalbard: Adaptation to Extreme Environments

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