The relationship between whole-blood serotonin and subjective mood in apparently healthy postmenopausal women

The human physiology of well-being: A systematic review on the association between neurotransmitters, hormones, inflammatory markers, the microbiome and well-being

To understand the pathways through which well-being contributes to health, we performed a systematic review according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines on the association between well-being and physiological markers in four categories, neurotransmitters, hormones, inflammatory markers, and microbiome. We identified 91 studies. Neurotransmitter studies (k_{number of studies}=9) reported only a possible positive association between serotonin and well-being. For the hormone studies (k = 48), a lower momentary cortisol level was related to higher well-being (meta-analytic r = -0.06), and a steeper diurnal slope of cortisol levels. Inflammatory marker studies (k = 36) reported negative or non-significant relations with well-being, with meta-analytic estimates of respectively r = -0.07 and r = -0.05 for C-reactive protein and interleukin-6. Microbiome studies (k = 4) reported inconsistent associations between different bacteria abundance and well-being. The results indicate possible but small roles of serotonin, cortisol, and inflammatory markers in explaining differences in well-being. The inconsistent and limited results for other markers and microbiome require further research. Future directions for a complete picture of the physiological factors underlying well-being are proposed.

A 16-week concurrent exercise program improves emotional well-being and emotional distress in middle-aged women: the FLAMENCO project randomized controlled trial

OBJECTIVE

To analyze the influence of a supervised concurrent exercise program on emotional well-being and emotional distress in middle-aged women.

METHODS

This randomized controlled trial included 150 middle-aged women recruited for the FLAMENCO project. Participants were allocated into counseling (n = 75) or exercise (n = 75) groups. The counseling group attended conferences on healthy lifestyle (including diet and physical activity topics). The exercise group followed a 60-min concurrent (aerobic + resistance) exercise training 3 days/wk for 16 weeks. Emotional health was assessed with the Positive and Negative Affect Schedule (PANAS) in two diverse timeframes, state (PANAS-S) and trait (PANAS-T) ranging from 10 to 50, where higher scores reflect greater affective emotional health/experience (positive affect subscale) and greater emotional distress (negative affect subscale). The differences between the counseling and exercise groups in PANAS were analyzed by linear regression.

RESULTS

The total number of women for the per-protocol analyses was 111 divided into the counseling (n = 53) and exercise (n = 58) groups. After adjusting for body mass index and Mediterranean diet adherence, PANAS-S and PANAS-T-positive affect scores increased by 3.81 and 3.02, respectively, in the exercise group whereas they decreased by 0.15 and increased by 0.51 in the counseling group (both, P < 0.05). PANAS-T negative affect decreased by 4.10 in the exercise group whereas only decreased by 0.9 in the counseling group (P < 0.05).

CONCLUSION

A 16-week concurrent exercise program improved emotional experience in middle-aged women. Specifically, women in the exercise group significantly improved their emotional well-being and emotional distress through greater changes in positive affect and negative affect compared with the counseling group.

The effect of a randomized 12-week soy drink intervention on everyday mood in postmenopausal women

OBJECTIVE

Dietary soy may improve menopausal symptoms, and subsequently mediate mood. This novel study examines various doses of dietary soy drink on everyday mood stability and variability in postmenopausal women.

METHODS

Community-dwelling women (n = 101), within 7 years postmenopause, consumed daily either a low (10 mg, n = 35), medium (35 mg, n = 37), or high (60 mg, n = 29) dose of isoflavones, for 12 weeks. Menopausal symptoms and repeated measures of everyday mood (positive [PA] and negative [NA] affect) (assessed at four time points per day for 4 consecutive days, using The Positive and Negative Affect Schedule) were completed at baseline and follow-up.

RESULTS

The dietary soy intervention had no effect on everyday mood stability (for PA [F{2,70} = 0.95, P = 0.390] and NA [F{2,70} = 0.72, P = 0.489]) or variability (for PA [F{2,70} = 0.21, P = 0.807] and for NA [F{2,70} = 0.15, P = 0.864]), or on menopausal symptoms (for vasomotor [F{2,89} = 2.83, P = 0.064], psychological [F{2,88} = 0.63, P = 0.535], somatic [F{2,89} = 0.32, P = 0.729], and total menopausal symptoms [F{2,86} = 0.79, P = 0.458]). There were between-group differences with the medium dose reporting higher PA (low, mean 24.2, SD 6; and medium, mean 29.7, SD 6) and the low dose reporting higher NA (P = 0. 048) (low, mean 11.6, SD 2; and high, mean 10.6, SD 1) in mood scores. Psychological (baseline M = 18 and follow-up M = 16.5) and vasomotor (baseline M = 4.2 and follow-up M = 3.6) scores declined from baseline to follow-up for the overall sample.

CONCLUSIONS

Soy isoflavones had no effect on mood at any of the doses tested. Future research should focus on the menopause transition from peri to postmenopause as there may be a window of vulnerability, with fluctuating hormones and increased symptoms which may affect mood.

Association of obesity with serum leptin, adiponectin, and serotonin and gut microflora in beagle dogs

Background

Serotonin (5‐hydroxytryptamine, 5HT) is involved in hypothalamic regulation of energy consumption. Also, the gut microbiome can influence neuronal signaling to the brain through vagal afferent neurons. Therefore, serotonin concentrations in the central nervous system and the composition of the microbiota can be related to obesity.

Objective

To examine adipokine, and, serotonin concentrations, and the gut microbiota in lean dogs and dogs with experimentally induced obesity.

Animals

Fourteen healthy Beagle dogs were used in this study.

Methods

Seven Beagle dogs in the obese group were fed commercial food ad libitum, over a period of 6 months to increase their weight and seven Beagle dogs in lean group were fed a restricted amount of the same diet to maintain optimal body condition over a period of 6 months. Peripheral leptin, adiponectin, 5HT, and cerebrospinal fluid (CSF‐5HT) levels were measured by ELISA. Fecal samples were collected in lean and obese groups 6 months after obesity was induced. Targeted pyrosequencing of the 16S rRNA gene was performed using a Genome Sequencer FLX plus system.

Results

Leptin concentrations were higher in the obese group (1.98 ± 1.00) compared to those of the lean group (1.12 ± 0.07, P = .025). Adiponectin and 5‐hydroytryptamine of cerebrospinal fluid (CSF‐5HT) concentrations were higher in the lean group (27.1 ± 7.28) than in the obese group (14.4 ± 5.40, P = .018). Analysis of the microbiome revealed that the diversity of the microbial community was lower in the obese group. Microbes from the phylum Firmicutes (85%) were predominant group in the gut microbiota of lean dogs. However, bacteria from the phylum Proteobacteria (76%) were the predominant group in the gut microbiota of dogs in the obese group.

Conclusions and Clinical Importance

Decreased 5HT levels in obese group might increase the risk of obesity because of increased appetite. Microflora enriched with gram‐negative might be related with chronic inflammation status in obese dogs.

Leptin, adiponectin and serotonin levels in lean and obese dogs

Background

Serotonin (5-hydroytryptamine or 5HT) is associated with numerous behavioral and psychological factors and is a biochemical marker of mood. 5HT is involved in the hypothalamic regulation of energy consumption. 5HT controls appetite in the central nerve system (CNS) and stimulates intestinal mobility. There are few studies looking at the role of 5HT and the relationship between peripheral circulating serotonin and obesity. The aim of this study was to find any differences in leptin, adiponectin, and 5HT between lean and obese dogs and to identify correlations among these factors.

Results

Leptin, triglyceride (TG) and cholesterol levels were higher in the obese group (all p < 0.01). Adiponectin and 5HT levels were higher in the lean group compared to the obese group (p < 0.01). Leptin (r = 0.628, p < 0.01), TG (r = 0.491, p < 0.01) and cholesterol (r = 0.419, p < 0.01) were positively correlated with body condition score (BCS), and adiponectin (r = -0.446, p < 0.01) and 5HT (r = -0.490, p < 0.01) were negatively correlated with BCS. Leptin was negatively correlated with adiponectin (r = -0.294, p < 0.01) and 5HT (r = -0.343, p < 0.01). 5HT was negatively correlated with leptin (r = -0.343, p < 0.01), TG (r = -0.268, p < 0.05) and cholesterol (r = -0.357, p < 0.05).

Conclusions

5HT is an important appetite control neurotransmitter, but there are limited studies for 5HT levels related to obesity in dogs. To the best of our knowledge, this is the first study to evaluate peripheral 5HT levels in obese dogs. From this research, we can assume that 5HT may be correlated with canine obesity. Further studies will be needed to further elucidate the role of low serum 5HT levels in canine obesity.

Mood and cognition in healthy older European adults: the Zenith study

BACKGROUND

The study aim was to determine if state and trait intra-individual measures of everyday affect predict cognitive functioning in healthy older community dwelling European adults (n = 387), aged 55-87 years.

METHODS

Participants were recruited from centres in France, Italy and Northern Ireland. Trait level and variability in positive and negative affect (PA and NA) were assessed using self-administered PANAS scales, four times a day for four days. State mood was assessed by one PANAS scale prior to assessment of recognition memory, spatial working memory, reaction time and sustained attention using the CANTAB computerized test battery.

RESULTS

A series of hierarchical regression analyses were carried out, one for each measure of cognitive function as the dependent variable, and socio-demographic variables (age, sex and social class), state and trait mood measures as the predictors. State PA and NA were both predictive of spatial working memory prior to looking at the contribution of trait mood. Trait PA and its variability were predictive of sustained attention. In the final step of the regression analyses, trait PA variability predicted greater sustained attention, whereas state NA predicted fewer spatial working memory errors, accounting for a very small percentage of the variance (1-2%) in the respective tests.

CONCLUSION

Moods, by and large, have a small transient effect on cognition in this older sample.

Obesity, whole blood serotonin and sex differences in healthy volunteers

BACKGROUND

Obesity is a growing problem throughout Europe, where the rate has more than doubled over the past 20 years. Reduced circulating serotonin may contribute to the development of obesity. This study aimed to explore associations between whole blood (WB) serotonin concentrations and anthropometric measures.

METHODS

Healthy adult volunteers (N = 68) gave whole blood samples for measurement of WB serotonin, and underwent BMI waist circumference (WC) and waist-to-hip ratio (WHR) assessment as well as DEXA (dual energy X-ray absorptiometry) scans for anthropometric parameters. Student's t-tests determined differences in WB serotonin and anthropometric measures between sexes. Partial Pearson's correlations were carried out on anthropometric measures and WB serotonin.

RESULTS

For the whole sample, WB serotonin was significantly negatively correlated with BMI, WC, WHR as well as android, gynoid and total % body fat. Analysis by sex showed significant negative correlations between WB serotonin and android, gynoid as well as total fat in males, but not in females.

CONCLUSION

This dichotomy between the sexes implies that there may be sex differences in the way that serotonin interplays with the development of obesity and body fat distribution.

Supplemented zinc does not alter mood in healthy older European adults – a randomised placebo-controlled trial: the Zenith study

Objective

Older people are vulnerable to zinc deficiency, which may impact upon their mood. This randomised, placebo-controlled, double-blind intervention study aimed to investigate the effect of oral zinc gluconate supplementation (15 mg/d; 30 mg/d; and placebo) on subjective mood (affect) in older Europeans.

Subjects

Healthy volunteers (n 387) aged 55–87 years were recruited.

Setting

Volunteers in Rome (Italy; n 108) and Grenoble (France; n 91) were aged 70–87 years and those in Coleraine (Northern Ireland; n 93) and Clermont-Ferrand (France; n 95) were aged 55–70 years.

Design

Mood was measured using the Positive and Negative Affect Scale on four occasions per day over 4 d at baseline, 3 and 6 months post-intervention.

Results

Mixed ANOVA indicated that neither positive nor negative affect altered in response to zinc (15 mg/d or 30 mg/d) compared to placebo in either the 55–70 years or the ≥70 years age group.

Conclusions

These results suggest that zinc does not benefit mood in healthy older people.

Parental hopeful patterns of thinking, emotions, and pediatric palliative care decision making: a prospective cohort study

OBJECTIVE

To test the hypothesis that hopeful patterns of thoughts and emotions of parents of pediatric patients receiving palliative care consultative services are related to subsequent decisions, specifically regarding limit of intervention (LOI) orders.

DESIGN

Prospective cohort study.

SETTING

Children's hospital and surrounding region.

PARTICIPANTS

Thirty-three pediatric patients receiving palliative care consultative services who did not have LOI orders at time of cohort entry and their 43 parental adults.

MAIN EXPOSURES

Parental levels at time of cohort entry of hopeful patterns of thinking and emotions, in conjunction with perceptions about patients' health trajectories.

MAIN OUTCOME MEASURE

Enactment of an LOI order after entry into the cohort.

RESULTS

During the 6 months of observation, 14 patients (42.4%) had an LOI order enacted. In adjusted analyses, higher levels of parental hopeful patterns of thinking were significantly associated with increased odds of enactment of an LOI order (adjusted odds ratio [AOR], 2.73; 95% confidence interval [CI], 1.04-7.22). Increased odds of LOI enactment were associated to nonsignificant degrees with lower levels of parental positive affect (AOR, 0.44; 95% CI, 0.17-1.12), higher levels of parental negative affect (AOR, 2.02; 95% CI, 0.98-4.16), and parental perceptions of worsening health over time (AOR, 1.72; 95% CI, 0.73-4.07).

CONCLUSION

For pediatric patients receiving palliative care consultative services, higher levels of parents' hopeful patterns of thinking are associated with subsequent enactment of LOI orders, suggesting that emotional and cognitive processes have a combined effect on medical decision making.

Reliability Generalization

The assessment of positive affect (PA) and negative affect (NA) by means of the Positive Affect and Negative Affect Schedule has received a remarkable popularity in the social sciences. Using a meta-analytic tool—namely, reliability generalization (RG)—population reliability scores of both scales have been investigated on the basis of a random effects model in 147 studies. Correcting for measurement errors, the results demonstrate moderate to high internal consistency coefficients and variations of the PA and NA reliability scores with regard to time frame instructions, language of items, and sample characteristics. The percentage of PA and NA true score variance differs in subpopulations up to 11%. RG analysis of test–retest coefficients illustrates state-like fluctuations and trait-like stability of both scales. Calculations of the fail-safe number point at the robustness of the results. Applications of RG coefficients compared to single-study coefficients highlight the relevance of population coefficients for research and assessment situations.

Translational aspects of pharmacological research into anxiety disorders: the stress-induced hyperthermia (SIH) paradigm

In anxiety research, the search for models with sufficient clinical predictive validity to support the translation of animal studies on anxiolytic drugs to clinical research is often challenging. This review describes the stress-induced hyperthermia (SIH) paradigm, a model that studies the activation of the autonomic nervous system in response to stress by measuring body temperature. The reproducible and robust SIH response, combined with ease of testing, make the SIH paradigm very suitable for drug screening. We will review the current knowledge on the neurobiology of the SIH response, discuss the role of GABA(A) and serotonin (5-HT) pharmacology, as well as how the SIH response relates to infectious fever. Furthermore, we will present novel data on the SIH response variance across different mice and their sensitivity to anxiolytic drugs. The SIH response is an autonomic stress response that can be successfully studied at the level of its physiology, pharmacology, neurobiology and genetics and possesses excellent animal-to-human translational properties.

Folate status and mood: is there a relationship?

Objective

To explore the relationship between subjective mood, folate status and homocysteine in healthy individuals.

Design

Subjective mood assessments were completed twice daily over the course of one week using the Positive and Negative Affect Scale (PANAS). The PANAS is a validated scale which considers mood state on two distinct continua, one reflecting positive mood and the other negative mood, each requiring response to 10 adjectives on a Likert scale. A blood sample was taken on one occasion at the start of the week during which subjective mood was assessed and analysed for red-blood-cell (RBC) folate, serum folate and plasma homocysteine concentrations.

Subjects

Male volunteers aged 19–47 years (n= 58) were recruited from local industries.

Results

High concentrations of RBC folate were associated with less variability (lower standard deviation) in negative mood (P= 0.023). Subjective mood, however, was not related to serum folate or homocysteine.

Conclusions

This study appears to be the first to uncover an association between long-term folate status and subjective mood (employing the PANAS) in healthy males. More research is needed to further explore the relationship between nutritional status and mood.

Salivary cortisol, stress and mood in healthy older adults: the Zenith study

The aims of this study were to investigate the relationship between salivary cortisol, stress and mood and to look at the circadian rhythms of positive (PA) and negative (NA) mood in older adults. The participants were 41 healthy adults aged 55-69 years, recruited in Northern Ireland as part of the European Commission-funded Zenith project. Salivary cortisol samples were obtained twice a day (2.30 p.m. and 10.30 p.m.) for 7 consecutive days in conjunction with momentary measures of positive (PA) and negative mood (NA), using PANAS and a trait measure of perceived stress (Perceived Stress Scale). Salivary cortisol levels were measured using an enzyme-linked immunoassay kit. Higher perceived stress levels were associated with lower afternoon PA (r=-0.46, p=0.003) and higher afternoon (r=0.43, p=0.007) and evening (r=0.45, p=0.004) NA. Lower afternoon PA was correlated with higher evening cortisol concentrations (r=-0.47, p=0.002). Greater afternoon PA variability was associated with higher evening cortisol concentrations (r=0.38, p=0.015). A high intra-class correlation between cortisol and positive mood was found (r=0.67, p=0.009). Previously established rhythms for positive and negative mood were confirmed. Interestingly, there was no association between salivary cortisol levels and perceived stress in these healthy older adults. Further, more extensive research is required to better understand the apparent interplay between these variables and ageing.