Routine regularity during a global pandemic: Impact on mental health outcomes and influence of chronotype.

Among the public health recommendations for supporting mental health during the COVID-19 pandemic, many strategies had an impact on biological rhythms, like sleep hygiene, physical exercise and healthy eating habits. Considering the known relationship between circadian organization and mental health, our aim was to test the association between behavioral regularity and mental health, and its interaction with chronotype, in a large sample surveyed in Brazil. We collected longitudinal data using online questionnaires that assessed sociodemographic characteristics, behavioral routines, mental health (PHQ-9, GAD-7, WHO-5 scales), and chronotype estimation based on midpoint of sleep on free days - MSF (µMCTQ), in a sample of 1390 participants (81% females). We computed a Routine Regularity Score (RRS) that reflects regularity across four behaviors: sleep, eating, working, exercising. There was a strong negative association between RRS and the severity of anxiety and depressive symptoms (GAD-7 and PHQ-9 scores), which was weaker among participants with late MSF, and a strong positive association with well-being (WHO-5 scores). RRS was a mediator of the MSF-mental health association and a predictor of mental health states. This study provides empirical evidence that maintaining behavioral routines during times of hardship may serve as tools to alleviate the negative impact on mental health.

Human social isolation and stress: a systematic review of different contexts and recommendations for future studies

Abstract Objectives The emergence of the coronavirus disease 2019 (COVID-19) pandemic and subsequent lockdowns and social distancing measures adopted worldwide raised questions about the possible health effects of human social isolation. Methods We conducted a systematic review on PubMed, Scopus, and Embase electronic databases using terms related to human social isolation - defined as the isolation of an individual from regular routines and usual social contact - and psychological stress, searching for simulated or naturalistic isolation environments. We present the main results, as well as the validity and limitations of each model. PROSPERO registry number: CRD42021241880. Results Despite the diversity of contexts reviewed, some outcomes almost ubiquitously relate to psychological stress, i.e., longer periods, expectation of a longer period, confinement, lack of social interaction, and support. Based on the results, and considering that most studies were not designed for the purpose of understanding isolation itself, we propose a group of recommendations for future experimental or naturalistic research on the topic. Conclusion Evidence on the impact of different situations in which individuals are subjected to social isolation can assist in development of directed preventive strategies to support people under similar circumstances. Such strategies might increase the general public's compliance with social distancing as a non-pharmacological intervention for emerging infectious diseases.

Self-perceived rhythmicity in affective and cognitive functions is related to psychiatric symptoms in adolescents.

The objective of this study was to evaluate the relationship between self-perceived rhythms measured using the Mood Rhythm Instrument for adolescents (MRhI-Y) and depressive and psychiatric symptoms measured with the Children's Depressive Instrument (CDI) and the Strengths and Difficulties Questionnaire (SDQ). In this study, 186 adolescents were recruited in Rio Grande do Sul, Brazil. We performed a Spearman correlation analysis to evaluate the relationships between quantitative variables. All variables that had a statistically significant correlation were included in ANOVA multiple regression models. The dependent variables in the multiple regression analyses were CDI score and total and emotional scores on the SDQ. We found that only Cognitive self-perceived rhythmicity contributed significantly to the first multiple regression with CDI as the outcome variable. The second regression with SDQ Emotional score as the outcome variable showed that female sex, age, and self-perceived affective rhythmicity contributed significantly to the model. The third regression with SDQ total score as the outcome variable showed that chronotype, self-perceived cognitive symptoms, and affective rhythmicity contributed significantly to the model. In conclusion, we found that lower self-perceived rhythmicity in cognitive factors and higher self-perceived rhythmicity in affective factors were related to presence and intensity of psychiatric and depressive symptoms.

Chronobiological parameters as predictors of early treatment response in major depression.

BACKGROUND: Alterations in circadian system organization have been related to major depressive disorder manifestations. This study aimed to evaluate chronobiological parameters, such as sleep, levels of 6-sulfatoxymelatonin, and others derived from actimetry as potential predictors of adequate treatment response in MDD. METHODS: 98 adult women with confirmed diagnosis of MDD were included. Participants completed standard questionnaires (Hamilton Depression Rating Scale - HAM-D; Munich Chronotype Questionnaire - MCTQ) at baseline and after 4 weeks of treatment. Urinary samples for assessing 6-sulfatoxymelatonin were collected on the day before and immediately after pharmacological treatment administration, and 28 continuous days of actigraphy data were collected during the protocol. Participants were classified into Responder (R) or Non-responder (NR) to antidepressant treatment in 4 weeks (early responder), which was characterized by a ≥50 % decrease in the HAM-D score. RESULTS: The following biological rhythms variables significantly predicted a better treatment response in a model controlling for age, sex, and previous treatments: higher levels of activity (M10 - average activity in the 10 most active hours within the 24 h-day) and an earlier center of the 10 most active hours (M10c), as well as lower intradaily variability (IV) of light exposure. Sleep parameters and 6-sulfatoxymelatonin levels did not associate with treatment response prediction. LIMITATION: Actimetry data were not assessed before changing in the treatment plan. CONCLUSION: Different patterns in activity and light exposure might be linked to early antidepressant response.

Human Social Isolation and Stress: A Systematic Review of Different Contexts and Recommendations for Future Studies.

OBJECTIVES: The emergence of COVID-19 pandemic and subsequent lockdowns and social distancing measures adopted worldwide raised questions about the possible health effects of human social isolation. METHODS: We conducted a systematic review on PubMed, Scopus and Embase electronic databases using terms related to human social isolation - defined as the isolation of an individual from regular routines and usual social contact - and psychological stress, searching for simulated or naturalistic isolation environments. We present the main results, as well as the validity and limitations of each model. PROSPERO registry number: CRD42021241880. RESULTS: Despite the diversity of contexts reviewed, some outcomes almost ubiquitously relate to psychological stress, i.e. longer periods, expectation of a longer period, confinement, lack of social interaction and support. Based on the results, considering that most studies were not designed for the purpose of understanding isolation itself, we propose a group of recommendations for future experimental or naturalistic research on the topic. CONCLUSION: Evidence on the impact of different situations in which individuals are subjected to social isolation can assist in the development of directed preventive strategies to support people under similar circumstances. Such strategies might increase the compliance of the general public to social distancing as a non-pharmacological intervention for emerging infectious diseases.

Sleep disturbances, circadian activity, and nocturnal light exposure characterize high risk for and current depression in adolescence.

STUDY OBJECTIVES: Major depressive disorder (MDD) in adolescence is associated with irregularities in circadian rhythms and sleep. The characterization of such impairment may be critical to design effective interventions to prevent development of depression among adolescents. This study aimed to examine self-reported and actimetry-based circadian rhythms and sleep-wake behavior associated with current MDD and high risk (HR) for MDD among adolescents. METHODS: Ninety-six adolescents who took part in the IDEA-RiSCo study were recruited using an empirically developed depression-risk stratification method: 26 classified as low risk (LR), 31 as HR, and 39 as a current depressive episode (MDD). We collected self-report data on insomnia, chronotype, sleep schedule, sleep hygiene as well as objective data on sleep, rest-activity, and light exposure rhythms using actimetry for 10 days. RESULTS: Adolescents with MDD exhibited more severe insomnia, shorter sleep duration, higher social jetlag (SJL), lower relative amplitude (RA) of activity, and higher exposure to artificial light at night (ALAN) compared with the other groups. They also presented poorer sleep hygiene compared with the LR group. The HR group also showed higher insomnia, lower RA, higher exposure to ALAN, and higher SJL compared with the LR group. CONCLUSIONS: HR adolescents shared sleep and rhythm alterations with the MDD group, which may constitute early signs of depression, suggesting that preventive strategies targeting sleep should be examined in future studies. Furthermore, we highlight that actimetry-based parameters of motor activity (particularly RA) and light exposure are promising constructs to be explored as tools for assessment of depression in adolescence.

Handling missing data in rest-activity time series measured by actimetry.

A handling procedure of off-wrist episodes in actimetry time series of motor activity is presented using two records (regular vs. irregular sleep-wake cycle and daytime activity) of 14 consecutive days sampled in 1-minute epochs. We generated single missing value (NA) intervals of 1 h, 2 h, 4 h, 6 h, 12 h, and 24 h as well as random NA episodes following probabilistic rules to simulate real-life off-wrist episodes. Then, we replaced these episodes with "zeroes" (i.e., the default of immobility records), mean or median of the remaining 13 days corresponding to the missing bins. Single missing episodes of up to 12 h resulted in less than 5% variation from the original values. The irregular series showed higher variability in acrophase, MESOR, L5, M10 and RA compared to the regular series. Random missing allocation simulating real-life off-wrist episodes resulted in significant changes in most parameters, and the imputation of zeroes significantly increased the variance; however, replacing NA with mean or median resulted in patterns similar to those of NA. We recommend replacing 'zeroes' with NA whenever possible, given the risk of inflating invariance using zeroes. If the parameters cannot be computed in the presence of NA, we recommend using the weekly mean of corresponding timepoints.

Effects of lighting patterns in pubertal development and metabolism of female wistar rats.

Modern lifestyle is characterized by constant exposure to artificial light, which is associated with alterations in biological rhythms, abnormalities to reproductive cycles and metabolic changes. In this study, we aimed to evaluate the effects of four different lighting patterns on puberty timing and on possible metabolic changes in female Wistar rats. Additionally, we developed a machine learning algorithm to automatically classify the stages of the estrous cycle. Adult Wistar rats mated during a week at a photoperiod station where they were exposed to combined red-green-blue lights (RGB) during the photoperiod that varied its spectral composition (i.e., variable color temperature) during the day (RGB-v; N = 14), RGB during the photoperiod with a fixed light color temperature (RGB-f; N = 13) during the whole photoperiod; constant darkness (DD; N = 13) and constant fixed light (LL; N = 15). Experiments were performed only on female litters from postnatal day (PND) 22 to 50. Body weight, puberty onset, estrous cyclicity and serum metabolic parameters were measured. We also collected pictures of vaginal smears to create a dataset of 15,936 images to construct an automatic classifier based on convolutional neural networks. No significant differences were found in the age of vaginal opening; however, the RGB-v group showed a significantly lower number of complete and consecutives cycles. Also, the RGB-f group showed the first complete estrous cycle significantly earlier than the RGB-v group. Female rats housed in LL condition presented significantly lower mean body weight from PND 33 to PDN 47 compared to the other groups. Furthermore, higher levels of plasma triglycerides were found in the DD group compared to RGB-f and RGB-v. HDL levels were significantly lower in RGB-v compared to RGB-f and LL groups. Total cholesterol was significantly lower in RGB-v compared to all groups. Visceral fat was significantly higher in RGB-f compared to the LL group. These results suggest that both changes in photoperiod and lighting quality affect pubertal development and alter lipid profiles and visceral fat accumulation.

The Brazilian-Portuguese version of the Sleep Hygiene Index (SHI): validity, reliability and association with depressive symptoms and sleep-related outcomes.

OBJECTIVE: To translate the Sleep Hygiene Index (SHI) to Brazilian Portuguese, to describe its psychometric properties and to show its association with sleep quality, daytime sleepiness, risk for sleep apnea and depressive symptoms. METHODS: Thirty subjects participated in the cultural adaptation and the item clarity evaluation. Twenty subjects answered the instrument in three different time-points for test-retest reliability. Eighty adult workers completed the SHI, the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), the Beck Depression Inventory (BDI) and the STOP-BANG (S-B). RESULTS: SHI shows an acceptable internal consistency (Cronbach's α=0.75), as well as a high reproducibility (intraclass correlation=0.972, p<0.01). The three final factors of confirmatory factor analysis extract an average of 48.22% of the total sample variance. Worse sleep hygiene (higher SHI score) correlated with poor sleep quality (r=0.398, p<0.001), excessive daytime sleepiness (r=0.406, p<0.001) and depressive symptoms (r=0.324, p=0.003). No correlations with S-B were found. CONCLUSIONS: SHI presents satisfactory-to-optimal psychometric properties. This instrument is useful for treatment planning and management of sleep hygiene practices. Thus, it represents a reliable way of assessing sleep hygiene quantitatively in both research and clinical settings.