Evaluation of salivary melatonin concentrations as a circadian phase maker of morning awakening and their association with depressive mood in postpartum mothers

Modulation of neural circuits by melatonin in neurodegenerative and neuropsychiatric disorders

Neurodegenerative and neuropsychiatric disorders are two broad categories of neurological disorders characterized by progressive impairments in movement and cognitive functions within the central and peripheral nervous systems, and have emerged as a significant cause of mortality. Oxidative stress, neuroinflammation, and neurotransmitter imbalances are recognized as prominent pathogenic factors contributing to cognitive deficits and neurobehavioral anomalies. Consequently, preventing neurodegenerative and neuropsychiatric diseases has surfaced as a pivotal challenge in contemporary public health. This review explores the investigation of neurodegenerative and neuropsychiatric disorders using both synthetic and natural bioactive compounds. A central focus lies on melatonin, a neuroregulatory hormone secreted by the pineal gland in response to light-dark cycles. Melatonin, an amphiphilic molecule, assumes multifaceted roles, including scavenging free radicals, modulating energy metabolism, and synchronizing circadian rhythms. Noteworthy for its robust antioxidant and antiapoptotic properties, melatonin exhibits diverse neuroprotective effects. The inherent attributes of melatonin position it as a potential key player in the pathophysiology of neurological disorders. Preclinical and clinical studies have demonstrated melatonin's efficacy in alleviating neuropathological symptoms across neurodegenerative and neuropsychiatric conditions (depression, schizophrenia, bipolar disorder, and autism spectrum disorder). The documented neuroprotective prowess of melatonin introduces novel therapeutic avenues for addressing neurodegenerative and psychiatric disorders. This comprehensive review encompasses many of melatonin's applications in treating diverse brain disorders. Despite the strides made, realizing melatonin's full neuroprotective potential necessitates further rigorous clinical investigations. By unravelling the extended neuroprotective benefits of melatonin, future studies promise to deepen our understanding and augment the therapeutic implications against neurological deficits.

Maternal Sleeping Problems Before and After Childbirth - A Systematic Review

The perinatal and postpartum period is of great significance for women due to physiological changes, shifts in circadian rhythms, social setting, and psychological well-being, all of which affect the quality and quantity of their sleep. A mixed-studies systematic review was undertaken to enhance our understanding of sleep disturbances and mood disorders in women in late pregnancy and the postpartum period, their connection with breastfeeding, and the assessment of interventions for sleep disturbance. Three electronic databases (PUBMED, EMBASE and Google Scholar) were searched for qualitative, observational, and mixed-method studies from the year 2016 to June 2023. Twenty-nine articles were included in the analysis. The results were synthesized into four overarching themes: (і) the sleep quality of women in the perinatal period; (ii) the relationship between sleep and breastfeeding; (iii) the relationship between sleep quality and emotional disturbance in the perinatal period; (iv) sleep interventions in the researched group. The subjective nature of the perception of sleep disturbances, along with the absence of an objective measurement tool is clearly an inconvenience. It is advisable to include the assessment of maternal sleep hygiene and family sleep patterns during postpartum healthcare provider appointments to develop strategies not only for women's sleep quality but also for their mental well-being.

Sleep, circadian activity patterns and postpartum depression: A systematic review and meta-analysis of actigraphy studies

Transition to motherhood is a period full of challenges and demands. In this review, we focused on the associations of sleep and circadian activity patterns during and after pregnancy with postpartum mental health factors. A systematic review and meta-analysis were conducted (PROSPERO reference 316,505). A search for articles was performed using PsycARTICLES, PsycINFO, PubMed, MEDLINE, Scopus, Cochrane, DARE, hand search, and citation tracking. The search was meant to identify peer-reviewed, experimental and observational studies reporting on women over 18 years old that assessed sleep and circadian activity patterns during pregnancy or postpartum using actigraphy, and investigated postpartum mental health factors. Nineteen relevant publications were selected. Postpartum total sleep at night was the indicator that was most closely related to the psychological functioning of women after childbirth. The results of the systematic review indicated that postpartum total sleep at night was related to postpartum fatigue, and the results of the meta-analysis suggested that total sleep at night was most strongly linked with postpartum depression. More studies are needed to estimate the associations of sleep-wake rhythm during pregnancy and in the postpartum period with postpartum mental health factors.

Mood Status Response to Physical Activity and Its Influence on Performance: Are Chronotype and Exercise Timing Affect?

PURPOSE

It is well known that there is an obvious 24 h diurnal variation in the individual's mood state and physiological activity, and training at different times of the day may lead to different exercise performance and metabolic outcomes; however, the time-dependent effect of emotional state on physical activity and the influence of its circadian rhythm on exercise performance are still not comprehensively understood. Based on this, this study summarizes the rhythmic experimental research in the field of sport psychology, and it aims to provide the basis for coaches to optimize sports training scientifically and to improve the mental health of the related crowd to the greatest extent.

METHODS

The systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched the PubMed, Web of Science, Medline, and CNKI databases for relevant literature; the search scope was research before September 2022.

RESULTS

13 studies comprising 382 subjects examined the effects of exercise timing on mood responses to exercise or the effects of circadian rhythms of mood on exercise performance, which included 3 RCTs and 10 Non-RCTs. The subjects included athletes (both training or retired), college students, and healthy adults. Two studies were designed for long-term exercise intervention (aerobic training and RISE) and the rest for acute intervention (CrossFit training, HIIT, aerobic combined with muscle conditioning training, constant power exhaustion training, and cycling) or physical function tests (RSA + BTV tests, 30 s Wingate test, muscle strength + CMJ + swimming performance test, RSSJA, shooting accuracy tests + 10 × 20 m dribbling sprint, 200 m time trials). All trials reported specific exercise timing; of these, 10 studies reported subjects' chronotypes, most commonly using the MEQ scale, while 1 recorded with the CSM. Mood responses were assessed with the POMS scale in 10 studies, while 3 other studies used the UMACL, PANAS, and GAS scales, respectively.

CONCLUSION

There was much inconsistency between the results, with subjects likely to be exposed to more sunlight (the main timing factor of the circadian rhythm) during early morning exercise, resulting in feeling more positive emotions; however, following a night's rest, delayed responses and poor functioning of the various organ systems of the human body may also lead to higher feelings of fatigue and negative emotions indirectly. Conversely, for athletes, their physical function tests are also more susceptible to the circadian rhythm of emotions, suggesting the importance of synchronizing them. In addition, night owls' emotional state during physical activity seems to be more susceptible to exercise timing than that of early birds. In order to achieve the best emotional state, it is suggested that night owls arrange courses in the afternoon or evening in future training.

The relationship between perinatal circadian rhythm and postnatal depression: an overview, hypothesis, and recommendations for practice

Postnatal depression (PND) is an important public health problem with far-reaching consequences for mothers, families, and society. Current treatment approaches tend to focus on the depressive symptoms of the mother. We propose the need for a shift in the conceptualisation of PND and its management, by focusing on circadian rhythm as an early manifestation of mother-infant synchrony. We have reviewed the relevant interdisciplinary literature to formulate a hypothesis and suggest recommendations for practice. We hypothesise that, after a mother’s circadian rhythm becomes ‘desynchronised’ immediately following birth, persistence of this disruption is implicated in the development of PND. This has important implications for novel treatment strategies in the critical and vulnerable postnatal period, for example the use of outdoor-based interventions and light.

Sleep duration of lactating mothers and its relationship with feeding pattern, milk macronutrients and related serum factors: A combined longitudinal cohort and cross-sectional study

Objective

Insufficient sleep is common in postpartum mothers. The main objectives of this study are to explore the sleep duration among Chinese lactating mothers and preliminarily investigate the relationship between sleep duration and feeding pattern. The secondary objectives are to investigate the relationships between sleep duration and milk macronutrients and between maternal-related indicators, including melatonin (MT), growth hormone (GH), ghrelin (GHRL), glucagon-like peptide-1 (GLP-1), prolactin (PRL), and cholecystokinin (CCK).

Methods

The present study comprises a longitudinal and a cross-sectional cohort from December 2019 to December 2021. Postpartum lactating women living in Shanghai were recruited through online and offline recruitment. The subjects were included in the longitudinal cohort or cross-sectional study based on their lactation period at the time of recruitment. The longitudinal cohort included a total of 115 mothers. Human milk and feeding pattern were measured and collected at 2–4 months and 5–7 months postpartum. At four predetermined follow-up time points, data on sleep duration was collected (at the time of recruitment, 2–4 months postpartum, 5–7 months postpartum, and 12–17 months postpartum). The cross-sectional study included 35 lactating mothers (2–12 months postpartum) who reported their sleep duration and provided blood samples. Mid-infrared spectroscopy (MIRS) method was used to analyze the macronutrients of breast milk, while MT, GH, GHRL, GLP-1, PRL, and CCK in maternal blood were determined by ELISA.

Results

The maternal sleep duration before pregnancy was 8.14 ± 1.18 h/d (n = 115), 7.27 ± 1.31 h/d (n = 113) for 2–4 months postpartum, 7.02 ± 1.05 h/d (n = 105) for 5–7 months postpartum, and 7.45 ± 1.05 h/d (n = 115) for 12–17 months postpartum. The incidence of insufficient sleep (<7 h/d) before pregnancy (12.17%) was significantly less than at any follow-up time after delivery (vs. 2–4 months postpartum, χ² = 10.101, p = 0.001; vs. 5–7 months postpartum, χ² = 15.281, p < 0.0001; vs. 12–17 months postpartum, χ² = 6.426, p = 0.011). The percentage of insufficient maternal sleep was highest at 5–7 months postpartum (34.29%). No significant difference was found between the incidence of insufficient sleep at 5–7 months postpartum, 2–4 months postpartum (29.20%, χ² = 0.650, p = 0.420), and 12–17 months postpartum (25.22%, χ² = 2.168, p = 0.141). At 2–4 months postpartum, the frequency of formula feeding per day is related to reduced maternal sleep duration (Standardization coefficient β = −0.265, p = 0.005, Adjusted R² = 0.061). At 2–4 months and 5–7 months postpartum, the relationship between macronutrients in breast milk and the mother's sleep duration was insignificant (all p > 0.05). Other than the positive correlation found between maternal GHRL and sleep duration (r = 0.3661, p = 0.0305), no significant relationship was observed between sleep duration and other indexes (all p > 0.05).

Conclusions

Postpartum mothers generally sleep less, but there is no correlation between insufficient sleep and the macronutrient content of breast milk. Formula feeding may be related to the mother's sleep loss, while breastfeeding (especially direct breastfeeding) may be related to increased maternal sleep duration. The findings suggest that sleep duration is related to maternal serum GHRL. More high-quality studies are needed to clarify the mechanism of these findings and provide a solid theoretical basis and support references for breastfeeding.

How do maternal emotion and sleep conditions affect infant sleep: a prospective cohort study

BACKGROUND

Recent studies suggest that the incidence of infant sleep disorder is related to maternal emotional and sleep conditions, but how they influence each other is not fully understood.

METHODS

A total of 513 pairs of parents and infants were enrolled in this prospective cohort study. Maternal emotional and sleep conditions were assessed using a self-rating depression scale, self-rating anxiety scale, and Pittsburgh Sleep Quality Index at the third trimester and within 3 months after delivery. Infant sleep was assessed by the Brief Screening Questionnaire for Infant Sleep Problems within 3 months after birth. Expression of the glucocorticoid receptor (GR), melatonin receptors (MR), exchange proteins directly activated by cAMP (EPAC) receptors, and dopamine receptor (DR) in the placenta was detected by immunohistochemistry. Methylation of the promoter regions for the GR (NR3C1 and NR3C2), MR (MTNR1A and MTNR1B), EPAC (RASGRF1 and RASGRF2), and DR (DRD1 and DRD2) genes was assessed by next generation sequencing-based bisulfite sequencing PCR.

RESULTS

The incidence of sleep disorders in infants 0-3 months of age in this cohort was 40.5%. Risk factors for infant sleep disorder were low education level of the father, depression of father, maternal postpartum depression, postpartum anxiety, postpartum sleep disorder, and maternal sleep disorder extend from the third trimester to postpartum. There was no difference in expression of placental DR, GR, MR, and EPAC between mothers whose infants were with and without sleep disorders. Methylation of MTNR1B was higher and expression of MR was lower in the placenta of mothers with sleep disorder in the third trimester than in mothers without sleep disorder. Level of NR3C2 methylation was lower and GR expression was higher in the placenta of mothers with sleep disorder extend from the third trimester to postpartum than in mothers without sleep disorder.

CONCLUSION

Maternal sleep disorders in the third trimester could lead to decreased MR expression by up-regulating MTNR1B methylation, and then resulting in elevated cortisol and increased GR expression by down-regulating NR3C2 methylation, which could increase the incidence of maternal postpartum sleep disorders, finally, the maternal postpartum sleep disorder could result in the high incidence of infant sleep disorder.

Antidepressant actions of melatonin and melatonin receptor agonist: Focus on pathophysiology and treatment

Depression has become one of the most commonly prevalent neuropsychiatric disorders, and the main characteristics of depression are sleep disorders and melatonin secretion disorders caused by circadian rhythm disorders. Abnormal endogenous melatonin alterations can contribute to the occurrence and development of depression. However, molecular mechanisms underlying this abnormality remain ambiguous. The present review summarizes the mechanisms underlying the antidepressant effects of melatonin, which is related to its functions in the regulation of the hypothalamic-pituitary-adrenal axis, inhibition of neuroinflammation, inhibition of oxidative stress, alleviation of autophagy, and upregulation of neurotrophic, promotion of neuroplasticity and upregulation of the levels of neurotransmitters, etc. Also, melatonin receptor agonists, such as agomelatine, ramelteon, piromelatine, tasimelteon, and GW117, have received considerable critical attention and are highly implicated in treating depression and comorbid disorders. This review focuses on melatonin and various melatonin receptor agonists in the pathophysiology and treatment of depression, aiming to provide further insight into the pathogenesis of depression and explore potential targets for novel agent development.