The relationship between biological rhythm and perceived social support, coping styles and medication adherence in patients with bipolar disorder in Türkiye

INTRODUCTION

The disruption of biological rhythm (sleep, eating patterns, hormonal secretions, activities, and social life etc.) in individuals diagnosed with bipolar disorder makes it challenging to balance the mood of the patient and facilitates recurrence. Although social support, coping with stress, and medication adherence are known to affect prognosis, no study has been found to investigate the relationship between these factors and biological rhythm.

AIM

This descriptive and correlational design study investigated the relationship between perceived social support, coping styles and medication adherence, and biological rhythm in individuals diagnosed with bipolar disorder.

METHOD

This study was conducted with 111 patients receiving treatment in the outpatient clinics of the psychiatry department of two public hospitals in Ankara, Turkey. Biological Rhythm Interview of Assessment in Neuropsychiatry (BRIAN), Multidimensional Scale of Perceived Social Support (MSPSS), Coping Style Inventory (CSI), and Morisky Medication Adherence Scale (MMAS) were used for data collection.

RESULTS

The biological rhythm total and subscales scores were significantly and negatively related to perceived social support total, and subscales scores (p < 0.005). The biological rhythm total and most of its subscales scores were significantly and negatively related to medication adherence (p < 0.005). The biological rhythm total and domain scores were significantly and negatively related to seeking social support, self-confident, and optimistic subscales of CSI while significantly and positively related to helpless and submissive (p < 0.005).

DISCUSSION

In this study, a positive relationship was found between increased perceived social support, effective coping with stress, and adherence to medication. This study highlights that these factors may be helpful for the regulation of biological rhythm.

Relationship between biological rhythm dysregulation and suicidal ideation in patients with major depressive disorder

BACKGROUND

Although the disturbance of circadian rhythms represents a significant clinical feature of major depressive disorder (MDD), the relationship between biological rhythm disturbances and the severity of suicidal ideation in individuals with MDD remains unclear. We aimed to explore the characteristics of different biological rhythm dimensions in MDD and their association with the severity of depressive symptoms and suicidal ideation.

METHODS

A total of 50 MDD patients and 50 healthy controls were recruited and their general information was collected. The severity of depressive symptoms was assessed with the 17-item Hamilton Depression Rating Scale (HDRS17). The intensity of suicidal ideation was evaluated with the Beck Scale for Suicide Ideation (BSS). The Chinese version of the Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN) scale was utilized to assess the participants' biological rhythm dysregulation. Multiple logistic regression analysis was conducted to explore the relationship between biological rhythm and the risk of MDD. Multiple linear regression analysis was performed in the MDD group to investigate the relationship between different biological rhythm dimensions and suicide ideation.

RESULTS

Significant differences were observed between the MDD group and the control group in total BRIAN score (Z=-5.41, P < 0.001) as well as scores for each dimension. After adjusting for confounding factors, multiple logistic regression analysis revealed a significant association between total BRIAN score and the presence of MDD (OR = 1.20, 95% CI = 1.10-1.29, P < 0.001), as well as between scores in different BRIAN dimensions and the presence of MDD (activity: OR = 1.47, 95% CI = 1.24-1.74, P < 0.001; sleep: OR = 1.52, 95% CI = 1.28-1.79, P < 0.001; social: OR = 1.80, 95% CI = 1.32-2.46, P < 0.001; eating pattern: OR = 1.34, 95% CI = 1.12-1.60, P = 0.001). In patients with MDD, linear regression analysis demonstrated a positive relationship between BSS scores and BRIAN eating pattern scores (β = 0.34, P = 0.022), even after adjusting for demographic factors and the severity of depression.

CONCLUSIONS

Patients with MDD exhibited significantly higher levels of dysregulation in all four biological rhythm dimensions compared to healthy controls and the degree of dysregulation was associated with the severity of depression. More importantly, dysregulation of eating pattern may increase the intensity of suicidal ideation in MDD, thus elevating the risk of suicide.

Moderating effects of smoking and drinking on the relationship between biological rhythm and psychological health and gender differences among adolescents

OBJECTIVES

To determine whether smoking and drinking moderate the correlation between biological rhythm and mental health and the role of gender differences in these moderating effects.

METHODS

Adolescents from three cities, all twelve middle schools (N = 7,986), named Shenzhen, Nanchang and Shenyang in China, were asked to complete a standardized questionnaire including the details of biological rhythm, psychological health, and the status of smoking and drinking. The PROCESS program was used to analyze whether smoking and drinking moderated the relationship between biological rhythm and psychological health.

RESULTS

The analyses revealed poorer psychological health and greater likelihood of smoking and drinking in participants with higher scores for biological rhythm disorder (P < 0.001). Specifically, smoking and drinking accelerated the relationship between biological rhythm and psychological health in the total sample (B = 0.05, P < 0.05; B = 0.06, P < 0.001) and only the subgroup of girls (B = 0.09, P < 0.05; B = 0.12, P < 0.001), respectively.

CONCLUSIONS

As the findings suggest, attention should be given to smoking, drinking and gender-specific approaches employed to alleviate the psychological disorders of adolescents with biological rhythm disorders.

Nonlinear relationship between sleep midpoint and depression symptoms: a cross-sectional study of US adults

BACKGROUND

Despite the close relationship between sleep-wake cycles and depression symptoms, the relationship between sleep midpoint and depression symptoms in adults remains understudied.

METHODS

In this cross-sectional study, 18280 adults aged ≥ 18 years from the National Health and Nutrition Examination Survey (NHANES) 2015-2020 were analyzed. Covariates included age, sex, race/ethnicity, education level, marital status, family income, body mass index, smoking status, drinking status, physical activity, comorbid condition, sleep duration, and sleep disturbance were adjusted in multivariate regression models.

RESULTS

Weighted restricted cubic spline based on the complex sampling design of NHANES showed that in participants with a sleep midpoint from 2:18 AM to 6:30 AM, the prevalence of depression symptoms increased by 0.2 times (adjusted odds ratio [OR] = 1.20, 95% confidence interval [CI]: 1.08-1.33) per 1-h increment in sleep midpoint compared to the reference point of 2:18 AM. For participants with a sleep midpoint after 6:30 AM and before 2:18 AM the next day, the relationship between sleep midpoint and depression symptoms was not significant after adjusting for all covariates (adjusted OR = 1.01, 95% CI: 0.99-1.03).

CONCLUSIONS

The findings indicate a significant nonlinear association between sleep midpoint and depression symptoms in a nationally representative sample of adults.

Artificial light at night at environmental intensities disrupts daily rhythm of the oyster Crassostrea gigas

Artificial Light At Night (ALAN) masks the natural light cycles and thus can disturb the synchronization of organisms' biological rhythms with their environment. Although coastlines are highly exposed to this growing threat, studies concerning the impacts of ALAN on coastal organisms remain scarce. In this study, we investigated the ALAN exposure effects at environmentally realistic intensities (0.1, 1, 10, 25 lx) on the oyster Crassostrea gigas, a sessile bivalve subject to light pollution on shores. We focused on the effects on oyster's daily rhythm at behavioral and molecular levels. Our results showed that ALAN disrupts the oyster's daily rhythm by increasing valve activity and annihilating day / night differences of expression of circadian clock and clock-associated genes. ALAN effects occur starting from 0.1 lx, in the range of artificial skyglow illuminances. We concluded that realistic ALAN exposure affects oysters' biological rhythm, which could lead to severe physiological and ecological consequences.

Effects of low dose radiation on behavior rhythm of zebrafish (Danio rerio)

Biological rhythm refers to the internal regulation of various life activities of an organism, which are determined by the specific time structure sequences of each individual. Behavior rhythm is the most intuitive embodiment of biological rhythm. To study the effect of low dose radiation on behavioral rhythm, zebrafish (Danio rerio) was used as a model organism in this study. The early embryos of zebrafish were irradiated at doses of 0.01, 0.1, and 1 Gy to observe the changes in zebrafish development, circadian rhythm, key clock genes, related RNA and protein expression, and melatonin. The results revealed that 0.1 and 1 Gy radiation could lead to different degrees of telencephalic nerve cell apoptosis and the formation of vacuolar structures. 0.1 and 1 Gy radiation could reduce the hatching rate of zebrafish embryos at 72 hpf and delay embryo hatching. The analysis of circadian behavior at 120 hpf demonstrated that 1 Gy dose of radiation altered the circadian rhythm of zebrafish, as well as decreased the distance, amplitude, and phase of movement. RT-PCR analysis of the key clock genes (bmal1b, clock1a, per1b, per2, cry2, and nr1d1) involved in regulating circadian rhythm was performed. The results showed that 1 Gy radiation could interfere with the expression of clock genes in zebrafish embryos and upregulate bmal1b, clock1a, and per1b. Western blot experiments further verified the protein expression of key clock genes, bmal1b and clock. Detection of melatonin secretion at different time points over 24 h showed that radiation doses of 0.1 and 1 Gy could increase melatonin secretion. Based on these findings, it is speculated that a certain dose of radiation may affect melatonin secretion, which impacts the telencephalon structure and ontogeny of zebrafish, delays hatching, and changes the circadian rhythm. This effect is thought to be achieved through upregulating the expression of circadian rhythm genes, clock1a and per1b and related proteins, which may be responsible for the abnormal circadian rhythm caused by radiation.

Dynamic molecular choreography of circadian rhythm disorders (DMCRD): a prospective cohort study protocol

BACKGROUND

Circadian rhythm disorders (CRDs) are closely associated with the occurrence and development of various diseases, such as inflammatory and cardiovascular diseases, as well as tumors. The impact of a CRD on bodily health is a complex and comprehensive process, and its molecular mechanisms and signaling pathways are still unclear. We therefore aimed to investigate the molecular mechanism variation and adverse outcomes associated with CRDs in a prospective cohort of CRD cases and controls at term using multiomics data. The study has been tasked with developing a precise health promotion model for the prevention and management of CRDs.

METHODS

This will be a 5-year prospective cohort study centered on the health management of individuals with CRDs. One hundred volunteers were recruited and had undergone baseline specimen collection, health examination, and health assessment. All of them will be followed up every year using the same protocol, and their biological specimens will be subjected to multiomics analysis after standardized processing.

DISCUSSION

Longitudinal health examination, health assessment, and multiomics data will be analyzed to study the impact of CRDs on the volunteers' health status. The results of this study will promote the development of targeted health management programs based on precision medicine.

TRIAL REGISTRATION

The clinical study registration has been completed (Trial Registration No. ChiCTR2100047242 ).

Monochromatic blue light not green light exposure is associated with continuous light-induced hepatic steatosis in high fat diet fed-mice via oxidative stress

Irregular light exposure is a newly identified environmental factor for the progression of lipid metabolism; however, the specific effect of light color exposure on lipid homeostasis remains unknown. Herein, 4-week-old male C57BL/6 J mice (n = 12) fed a high-fat diet (HFD) were exposed to a standard 12-h light: 12-h dark cycle (LD-WF) and a 24-h continuous monochromatic blue light (LL-BF), green light (LL-GF), or white light (LL-WF) condition for 12 weeks. LL-BF interfered with the expression of circadian genes in the hypothalamus and upregulated the plasma corticosterone (CORT) levels (p < 0.05) compared with LD-WF. Along with elevation of the CORT level, LL-BF enhanced glucocorticoid receptor synthesis, increased the Hsp90 mRNA level, reduced the antioxidant capacity, increased the production of ROS and MDA, and reduced the Pgc-1α mRNA level in the liver (p < 0.05). Furthermore, LL-BF disrupted the hepatic expression levels of genes involved in lipid metabolism, Acc and Hl, which further aggravated the hepatic steatosis status and significantly increased the liver pathological scores, TG, TC, IL-6, and TNF-α levels (p < 0.05). LL-BF consistently increased the body weight and incidence of dyslipidemia and lipid deposition. However, no difference was observed between LL-BF and LL-WF (p > 0.05). Surprisingly, LL-GF did not show any changes induced by LL-BF and LL-WF, and contrary to LL-BF, LL-GF and LD-WF showed no significantly differing changes (p > 0.05). Taken together, exposure to monochromatic blue light but not green light is associated with continuous light-aggravated hepatic steatosis in HFD-fed mice. The effect of continuous blue light exposure may be attributed to the disturbance of biological rhythm, increase in CORT secretion, induction of oxidative stress, and interference of the Acc and Hl levels in the liver.

Mental state, biological rhythm and social support among healthcare workers during the early stages of the COVID-19 epidemic in Wuhan

Background

The COVID-19 pandemic has put the mental health of healthcare workers at risk. However, the potential psychosocial factors underlying mental health problems, such as depression and anxiety, require further investigation. The present study aimed to explore the factors that influence the mental state of healthcare workers.

Methods

A total of 276 healthcare workers completed a set of online self-report questionnaires from February 2 to 5, 2020, in the following order: general information related to the COVID-19 outbreak, Biological Rhythms Interview of Assessment in Neuropsychiatry, Beck Depression Inventory-II, Beck Anxiety Inventory, and Social Support Rating Scale.

Results

Our study revealed that both social support and age moderated the ability of biological rhythm disturbance to exacerbate depression (R² = 0.47; effect size f² = 0.85). Higher levels of social support buffered the amplification of depression associated with increased biological rhythm disturbance in all age groups, and especially in younger individuals (mean age = 26.57, se = 0.04). Depressive symptoms were predicted by both social and sleeping rhythms, whereas anxiety symptoms were predicted only by social rhythm. Married individuals had lower biological rhythm disturbance ratings and higher social support ratings. Females also reported higher ratings in social support.

Conclusions

Our study suggests that biological rhythm intervention along with social support can reduce the negative effect of biological rhythm disturbance on mood disorders, especially in younger people. We also provide evidence for the ability of social support to buffer stress in a major health crisis and demonstrate the effects of marital status and sex, which provide a different perspective for studying mental crisis management.

Difference in the regulation of biological rhythm symptoms of Major depressive disorder between escitalopram and mirtazapine

BACKGROUND

Biological rhythm plays an important role in major depressive disorder (MDD). The efficacy of antidepressant in biological rhythm remains unclear. This study is designed to explore the efficiency of escitalopram and mirtazapine in improving circadian rhythm, diurnal mood variation(DMV) and daily activity in MDD patients.

METHODS

Four-hundred and fifty participants diagnosed with MDD were randomized to receive treatment with escitalopram (TWE), treatment with mirtazapine (TWM) or treatment as usual (TAU). Biological rhythm symptoms were assessed by relevant biological subscale in the Hamilton depression scale (HAMD) and the quick inventory of depressive symptomatology self-report (QIDS). The participants were assessed by trained evaluators at baseline and week 2, 4, 6 and 8.

RESULTS

The differences of HAMD score among TWE(58%, 69%, 72%), TWM(56%, 64%, 76%) and TAU(49%, 57%, 68%) were significant(P<0.05). But the differences were significant only in patients without DMV; (2) Sleep rhythm items (difficulty falling asleep and early-wake) were significantly improved in TWM (P <0 .05) for both HAMD and QIDS. Decreased appetite and weight were significantly improved in TWM (P<0 .05) for both scales. (3) For daily activity-related items, feeling slowed down and concentration were significantly improved in TWE. And the retardation was significantly improved in TWE and in TWM.

CONCLUSIONS

Both escitalopram and mirtazapine have superior anti-depressive effect, especially for MDD patients without DMV. Escitalopram was significantly more effective in daily activity, feeling slowed down and concentration difficulty, while mirtazapine was significantly more effective in improving sleep, appetite and weight of MDD.

Development and validation of the self-rating of biological rhythm disorder for Chinese adolescents

Modern lifestyles, and the popularization of artificial light at night, have led to maladjusted social time and internal circadian rhythm, so developing an instrument on biological rhythms is critical. A 36-item self-rated questionnaire assessing biological rhythm disorder in adolescents was developed according to the literature and expert evaluations. Based on a literature review, four dimensions, digital media use, sleep, eating habits, and activity, were determined. After preliminary item analysis, seven unqualified items were eliminated. A total of 1,152 college students and 8,082 middle school students were selected. Two independent sample t-tests, the Pearson correlations, and confirmatory factor analysis, were used to evaluate the reliability and validity of the questionnaire. The final questionnaire consisted of 4 dimensions covering 29 items, and the variance cumulative contribution was 62.65%. Cronbach's α for the total questionnaire was 0.950 and ranged from 0.817 to 0.904 for each dimension. The Pearson correlation coefficients between each item and the total score ranged from 0.360 to 0.755, and the Pearson correlation coefficient between each item and its dimension was between 0.575 and 0.841. Confirmatory factor analysis showed that the indices of CFI, TLI and RMSEA were 0.911, 0.901 and 0.043, respectively, which is a good degree of fit. The self-rating scale is consistent with the evaluation standard of psychometrics and can be used to evaluate the degree of biological rhythm disorder in adolescents.

Dosing-time dependent testicular toxicity of everolimus in mice

The circadian timing system controls many biological functions in mammals including drug metabolism and detoxification, cell cycle events, and thus may affect pharmacokinetics, target organ toxicity and efficacy of medicines. Selective mTOR (mammalian target of rapamycin) inhibitor everolimus is an immunosuppressant and anticancer drug that is effective against several cancers. The aim of this study was to investigate dosing-time dependent testicular toxicity of subacute everolimus administration in mice. C57BL/6 J male mice were synchronized with Light-Dark (12h:12 h) cycle, with Light-onset at Zeitgeber Time (ZT)-0. Everolimus (5 mg/kg/day) was administered orally to mice at ZT1_rest-span or ZT13_{activity-span} for 4 weeks. Body weight loss, clinical signs, changes in testicular weights, testis histology, spermatogenesis and proliferative activity of germinal epithelium of seminiferous tubules were examined. Steady-state everolimus concentrations in testes were determined with validated HPLC method. Everolimus toxicity was less severe following dosing at ZT13 compared to ZT1, as shown with least body weight loss (p<0.001), least reductions in testes weights (p<0.001) and least histopathological findings. Everolimus-induced histological changes on testes included vacuolisation and atrophy of germinal epithelium, and loss of germinal cell attachment. The severity of everolimus-induced histological toxicity on testes was significantly more evident in mice treated at ZT1 than ZT13 (p<0.001). Spermatogenic cell population significantly decreased when everolimus administered at ZT1 compared to ZT13 (p<0.001). Proliferative activity of germinal epithelium was significantly decreased due to treatment at ZT1 compared to ZT13 (p<0.001). Everolimus concentrations in testes indicated a pronounced circadian variation, which was greater in mice treated at ZT1 compared to ZT13 (p<0.05). Our study revealed dosing-time dependent testicular toxicity of everolimus in mice, which was greater in severity when everolimus administered at early rest-span (daytime-ZT1) than early activity-span (nighttime-ZT13). These findings support the concept of everolimus chronotherapy for minimizing reproductive toxicity and increasing the tolerability of everolimus, as a clinical advantage.

Natural daily patterns in fish behaviour may confound results of ecotoxicological testing

Low doses of neuroactive chemicals end up in the environment and disrupt behaviour of non-target organisms. Although a whole range of studies have documented pollutant-induced changes in behaviour, natural daily variability in behaviour is rarely taken into account. This is surprising because biological rhythms may affect the outcome of experiments, are adaptive and are expected to be sensitive to neurochemical exposure. Here, we exploit daily behavioural variation in the fish model Nothobranchius furzeri to examine if behavioural effects of chronic exposure (74 days) to an environmentally relevant level (28 ng/L) of the neurochemical fluoxetine depend on the time of day. Fluoxetine exposure induced an increase in anxiety-related behaviour that was slightly more pronounced in the evening compared to the morning. Moreover, open-field locomotor activity was disrupted and daily patterns in activity lifted upon exposure to the compound. These results imply that short-term behavioural variability should be considered both to standardise ecological risk assessment of neuroactive chemicals as well as to better understand the environmental impact of such compounds in aquatic ecosystems.

Collective Oscillations in Coupled-Cell Systems

We investigate oscillations in coupled systems. The methodology is based on the Hopf bifurcation theorem and a condition extended from the Routh–Hurwitz criterion. Such a condition leads to locating the bifurcation values of the parameters. With such an approach, we analyze a single-cell system modeling the minimal genetic negative feedback loop and the coupled-cell system composed by these single-cell systems. We study the oscillatory properties for these systems and compare these properties between the model with Hill-type repression and the one with protein-sequestration-based repression. As the parameters move from the Hopf bifurcation value for single cells to the one for coupled cells, we compute the eigenvalues of the linearized systems to obtain the magnitude of the collective frequency when the periodic solution of the coupled-cell system is generated. Extending from this information on the parameter values, we further compute and compare the collective frequency for the coupled-cell system and the average frequency of the decoupled individual cells. To compare these scenarios with other biological oscillators, we perform parallel analysis and computations on a segmentation clock model.

Lentinan Inhibited the Activation of Th2 Cells in Allergic Mice by Reducing the Amplitude of Changes in Biological Rhythm

INTRODUCTION

Biological rhythm is inextricably linked to the physiological mechanisms of allergic diseases, but the exact mechanisms are still poorly understood. Clinical studies have reported rhythmic fluctuations in allergic diseases. The search for natural and harmless active ingredients based on biological rhythm with which to regulate allergic diseases is essential for the control of food allergy.

METHODS

In this study, mice were treated at different time points to determine the link between the severity of allergic reactions and the circadian clock genes. The mice were treated with lentinan, either continuously or discontinuously, to assess their clinical symptoms, vascular permeability, immune cells, cytokines, and clock genes. Specifically, rat basophilic leukemia (RBL-2H3) cells were treated with lentinan and the rhythmic changes of cell degranulation were measured.

RESULTS

The results in different models showed that the allergic reactions in mice treated at different time points were significantly different and thus related to fluctuations in biological rhythm. Treatment with lentinan was found to reduce the amplitude of changes in the clock genes, such as the activation of Per and Cry proteins in allergic mice, as well as to regulate biological rhythm in cells, inhibit the activation of Th2 cells, and alleviate allergic reactions. Furthermore, lentinan changed the rhythm of degranulation in RBL-2H3 cells.

CONCLUSION

Lentinan was, therefore, determined to successfully alleviate allergic reactions by reducing the amplitude of changes in the body's biological rhythm, inhibiting the activation of Th2 cells, and affecting the immune microenvironment.

Seasonality in Bipolar Disorder: Impact on Mood Symptoms, Psychosocial Functioning, Neurocognition, and Biological Rhythm

Introduction

Even though an increase in the number of hospital admissions for manic and depressive periods at certain times of the year is reported in bipolar disorder (BD), mood symptoms do not show a seasonal variation. We aimed to find out the possible causes of increased hospital admissions of BD patients in certain periods of the year.

Methods

The study was carried out in four centers in Turkey. The patient group consisted of 41 persons with a diagnosis of BD in remission. The healthy control (HC) group consists of 37 persons. The selected evaluation times are fall equinox (September 23), spring equinox (March 21), summer solstice (June 21) and winter solstice (December 21). For mood symptoms, Hamilton Depression Rating Scale and Young Mania Rating Scale; for functioning Functioning Assessment Short Test; for neurocognition Stroop Test (ST) and Rey Auditory Verbal Learning Test (RAVLT), for biological rhythm Biological Rhythms Interview of Assessment in Neuropsychiatry, and Seasonal Pattern Assessment Questionnaire were used.

Results

In terms of mood symptoms no seasonal variation was found. Across all four periods of assessment of BD group, statistically significant variation was only observed in the instant recall, learning and recognition domains of RAVLT and word test and color test domains of ST; however, it was not sufficient to distinguish the BD group separating from the control group.

Conclusions

In terms of mood symptoms, psychosocial functionality, biological rhythm, neurocognition, no seasonal variation was demonstrated that could distinguish the BD group from the HC group.

Similarities of Aspects of Biological Rhythms between Major Depression and Bipolar II Disorder Compared to Bipolar I Disorder: A Finding from the Early-Onset Mood Disorder Cohort

OBJECTIVE

The biological rhythm is closely related to mood symptoms. The purpose of this study was to assess the differences in biological rhythms among subjects with mood disorder [bipolar I disorder (BD I), bipolar II disorder (BD II), major depressive disorder (MDD)] and healthy control subjects.

METHODS

A total of 462 early-onset mood disorder subjects were recruited from nine hospitals. The controls subjects were recruited from the general population of South Korea. Subject groups and control subject were evaluated for the Korean language version of Biological Rhythms Interview of Assessment in Neuropsychiatry (K-BRIAN) at the initial evaluation.

RESULTS

The mean K-BRIAN scores were 35.59 [standard deviation (SD)=13.37] for BD I, 43.05 (SD=11.85) for BD II, 43.55 (SD=12.22) for MDD, and 29.1 (SD=8.15) for the control group. In the case of mood disorders, biological rhythm disturbances were greater than that in the control group (p<0.05). A significant difference existed between BD I and BD II (BD I <BD II, p<0.001) and between BD I and MDD (BD I<MDD, p< 0.001) but no difference was observed between BD II and MDD.

CONCLUSION

BD II and MDD are similar to each other but different from BD I in biological rhythm patterns in early-onset mood disorder cases. Biological rhythm disturbances are similar for early-onset major depression and BD II.

Dosing depending on SIRT3 activity attenuates doxorubicin-induced cardiotoxicity via elevated tolerance against mitochondrial dysfunction and oxidative stress

Doxorubicin (DOX) is a potent anti-neoplastic agent with cumulative cardiotoxicity. DOX-induced cardiotoxicity has been shown to depend on the different dosing times. However, the basis for determining the dosing time to minimize DOX-induced cardiotoxicity and the underlying mechanisms remain incompletely understood. Here we first showed that SIRT3, the major mitochondrial deacetylase, is negatively correlated to DOX-induced cardiotoxicity through the regulation of ATP production, mitochondrial membrane potential (MMP) level and ROS level in human pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Then, we used in vivo experiments to demonstrate that DOX significantly reduced the SIRT3 expression and the SIRT3 activity as reflected by the increased Ac^K68MnSOD/MnSOD ratio in rats after six weeks of treatment. Notably, the activity of SIRT3 had an obvious diurnal rhythm pattern in the myocardium of healthy rats. More importantly, an obvious lower Ac^K68MnSOD/MnSOD ratio was observed in rat hearts with DOX administrated at Zeitgeber time (ZT) 9 (ZT 0 was the time lights were turned on) than ZT1, which represent the peak and trough of SIRT3 activity. Moreover, DOX ZT9 reduced the body weight loss, extended the survival period, improved the heart function and alleviated the myocardial lesions compared to DOX ZT1. Mechanistic investigations demonstrated that DOX ZT1 significantly reduced ATP production, oxygen consumption rate (OCR) at various respiration states, MMP level and MnSOD activity and enhanced the H₂O₂ level compared with CON ZT1, whereas there was no significant effect for DOX ZT9 compared with CON ZT9. Taken together, dosing at the peak time of SIRT3 activity reduced DOX-induced cardiotoxicity, which may be related to the increased endogenous tolerance against the mitochondrial dysfunction and oxidative stress caused by DOX.

Time-of-day of blood-feeding: effects on mosquito life history and malaria transmission

BACKGROUND

Biological rhythms allow organisms to compartmentalise and coordinate behaviours, physiologies, and cellular processes with the predictable daily rhythms of their environment. There is increasing recognition that the biological rhythms of mosquitoes that vector parasites are important for global health. For example, whether perturbations in blood foraging rhythms as a consequence of vector control measures can undermine disease control. To address this, we explore the impacts of altered timing of blood-feeding on mosquito life history traits and malaria transmission.

METHODS

We present three experiments in which Anopheles stephensi mosquitoes were fed in the morning or evening on blood that had different qualities, including: (i) chemical-induced or (ii) Plasmodium chabaudi infection-induced anaemia; (iii) Plasmodium berghei infection but no anaemia; or (iv) stemming from hosts at different times of day. We then compared whether time-of-day variation in blood meal characteristics influences mosquito fitness proxies relating to survival and reproduction, and malaria transmission proxies.

RESULTS

Mosquito lifespan is not influenced by the time-of-day they received a blood meal, but several reproductive metrics are affected, depending on other blood characteristics. Overall, our data suggest that receiving a blood meal in the morning makes mosquitoes more likely to lay eggs, lay slightly sooner and have a larger clutch size. In keeping with previous work, P. berghei infection reduces mosquito lifespan and the likelihood of laying eggs, but time-of-day of blood-feeding does not impact upon these metrics nor on transmission of this parasite.

CONCLUSION

The time-of-day of blood-feeding does not appear to have major consequences for mosquito fitness or transmission of asynchronous malaria species. If our results from a laboratory colony of mosquitoes living in benign conditions hold for wild mosquitoes, it suggests that mosquitoes have sufficient flexibility in their physiology to cope with changes in biting time induced by evading insecticide-treated bed nets. Future work should consider the impact of multiple feeding cycles and the abiotic stresses imposed by the need to forage for blood during times of day when hosts are not protected by bed nets.

Validation of the Korean Version of the Biological Rhythms Interview of Assessment in Neuropsychiatry

OBJECTIVE

The Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN) is a scale used to clinically evaluate disturbances in biological rhythm. In this study, we aimed to examine the reliability and validity of the Korean version of the BRIAN (K-BRIAN) in a Korean population.

METHODS

A total of 181 participants, including 141 outpatients with bipolar disorder (BD; type I, 62; type II, 79) and 40 controls, were recruited. Construct validity was tested by comparing the mean K-BRIAN scores of the BD patients and control subjects. Concurrent validity was tested by evaluating the association between the K-BRIAN and the Morningness-Eveningness Questionnaire (MEQ).

RESULTS

The mean K-BRIAN scores of the control subjects and patients with BD differed significantly (p<0.001). Particularly, the mean K-BRIAN score was considerably lower among control subjects (mean±standard deviation=35.00±8.88) than among patients with BD type I (41.19±12.10) and type II (50.18±13.73). The Cronbach's alpha for the K-BRIAN was 0.914. The K-BRIAN was found to correlate with the MEQ (r=-0.45, p<0.001).

CONCLUSION

The findings affirm that the K-BRIAN has good construct validity and internal consistency. This suggests that the K-BRIAN can be used to assess biological rhythms in the Korean population, especially for patients with mood disorder.

Salivary cortisol levels and biological rhythm in schoolchildren with sleep bruxism

OBJECTIVE

Salivary cortisol levels and biological rhythms could be hypothesized as part of the multifactorial framework that explains bruxism etiology. The objective of this study was to examine salivary cortisol levels and biological rhythms in schoolchildren with sleep bruxism (SB).

METHODS

This is a cross-sectional study with a school-based sample. The Biological Rhythms Interview for Assessment in Neuropsychiatry for Kids (BRIAN-K) was used to evaluate biological rhythms. Salivary samples were collected by the spitting method. The salivary cortisol level was measured by electrochemiluminescence. The criteria proposed by the American Academy of Sleep Medicine (AASM) were used to evaluate SB.

RESULTS

The SB prevalence was 16%. The SB presence was associated with belonging to families of lower economic status (p = 0.003). In addition, children with SB showed greater difficulty in maintaining biological rhythm (p = 0.002) and had higher levels of salivary cortisol (p = 0.034) compared with children without SB.

CONCLUSIONS

Higher levels of cortisol and disruption of biological rhythm was associated with SB in schoolchildren.

Molecular evidence for an intrinsic circadian pacemaker in the cardiac ganglion of the American lobster, Homarus americanus - Is diel cycling of heartbeat frequency controlled by a peripheral clock system?

Whether cardiac output in decapod crustaceans is under circadian control has long been debated, with mixed evidence for and against the hypothesis. Moreover, the locus of the clock system controlling cardiac activity, if it is under circadian control, is unknown. However, a report that the crayfish heart in organ culture maintains a circadian oscillation in heartbeat frequency suggests the presence of a peripheral pacemaker within the cardiac neuromuscular system itself. Because the decapod heart is neurogenic, with contractions controlled by the five motor and four premotor neurons that make up the cardiac ganglion (CG), a likely locus for a circadian clock is the CG itself. Here, a CG-specific transcriptome was generated for the lobster, Homarus americanus, and was used to assess the presence/absence of transcripts encoding putative clock-related proteins in the ganglion. Using known Homarus brain/eyestalk ganglia clock-related proteins as queries, BLAST searches of the CG transcriptome were conducted for the five proteins that form the core clock, i.e., clock, cryptochrome 2, cycle, period and timeless, as well as for a variety of clock-associated, clock input pathway and clock output pathway proteins. With the exception of pigment dispersing hormone receptor [PDHR], a putative clock output pathway protein, one or more transcripts encoding each of the proteins searched for were identified from the CG assembly; no PDHR-encoding transcripts were found. RT-PCR confirmed the expression of all core clock transcripts in multiple independent CG cDNAs; RNA-Seq data suggest that both the motor and premotor neurons could contribute to the cellular locus of a pacemaker. These data provide support for the possible existence of an intrinsic circadian clock in the H. americanus CG, and form a foundation for guiding future anatomical, molecular and physiological investigations of circadian signaling in the lobster cardiac neuromuscular system.

Circadian signaling in Homarus americanus: Region-specific de novo assembled transcriptomes show that both the brain and eyestalk ganglia possess the molecular components of a putative clock system

Essentially all organisms exhibit recurring patterns of physiology/behavior that oscillate with a period of ~24-h and are synchronized to the solar day. Crustaceans are no exception, with robust circadian rhythms having been documented in many members of this arthropod subphylum. However, little is known about the molecular underpinnings of their circadian rhythmicity. Moreover, the location of the crustacean central clock has not been firmly established, although both the brain and eyestalk ganglia have been hypothesized as loci. The American lobster, Homarus americanus, is known to exhibit multiple circadian rhythms, and immunodetection data suggest that its central clock is located within the eyestalk ganglia rather than in the brain. Here, brain- and eyestalk ganglia-specific transcriptomes were generated and used to assess the presence/absence of transcripts encoding the commonly recognized protein components of arthropod circadian signaling systems in these two regions of the lobster central nervous system. Transcripts encoding putative homologs of the core clock proteins clock, cryptochrome 2, cycle, period and timeless were found in both the brain and eyestalk ganglia assemblies, as were transcripts encoding similar complements of putative clock-associated, clock input pathway and clock output pathway proteins. The presence and identity of transcripts encoding core clock proteins in both regions were confirmed using PCR. These findings suggest that both the brain and eyestalk ganglia possess all of the molecular components needed for the establishment of a circadian signaling system. Whether the brain and eyestalk clocks are independent of one another or represent a single timekeeping system remains to be determined. Interestingly, while most of the proteins deduced from the identified transcripts are shared by both the brain and eyestalk ganglia, assembly-specific isoforms were also identified, e.g., several period variants, suggesting the possibility of region-specific variation in clock function, especially if the brain and eyestalk clocks represent independent oscillators.

Biological dysrhythm in remitted bipolar I disorder

BACKGROUND

Recent treatment guidelines support treatment of biological rhythm abnormalities as a part of treatment of bipolar disorder, but still, literature examining various domains (Sleep, Activity, Social, and Eating) of biological rhythm and its clinical predictors are less.

OBJECTIVES

The main aim of our study is to compare various domains of biological rhythm among remitted bipolar I subjects and healthy controls. We also explored for any association between clinical variables and biological rhythm among bipolar subjects.

METHODS

40 subjects with Bipolar I disorder and 40 healthy controls who met inclusion and exclusion criteria were recruited for the study. Diagnoses were ascertained by a qualified psychiatrist using MINI 5.0. Sociodemographic details, biological rhythm (BRIAN-Biological Rhythm Interview of assessment in Neuropsychiatry) and Sleep functioning (PSQI- Pittsburgh Sleep Quality Index) were assessed in all subjects.

RESULTS

Mean age of the Bipolar subjects and controls were 41.25±11.84years and 38.25±11.25 years respectively. Bipolar subjects experienced more biological rhythm disturbance when compared to healthy controls (total BRIAN score being 34.25±9.36 vs 28.2±6.53) (p=0.002). Subsyndromal depressive symptoms (HDRS) had significant positive correlation with BRIAN global scores(r=0.368, p=0.02). Linear regression analysis showed that number of episodes which required hospitalization (β=0.601, t=3.106, P=0.004), PSQI (β=0.394, t=2.609, p=0.014), HDRS (β=0.376, t=2.34, t=0.036) explained 31% of variance in BRIAN scores in remitted bipolar subjects.

CONCLUSION

Biological rhythm disturbances seem to persist even after clinical remission of bipolar illness. More studies to look into the impact of subsyndromal depressive symptoms on biological rhythm are needed.

The effects of individual biological rhythm differences on sleep quality, daytime sleepiness, and dissociative experiences

Individuals who differ markedly by sleep chronotype, i.e., morning-type or evening-type also differ on a number of psychological, behavioral, and biological variables. Among several other psychological functions, dissociation may also lead to disruption and alteration of consciousness, which may facilitate dream-like experiences. Our study was aimed at an inquiry into the effects of individual biological rhythm differences on sleep quality and daytime sleepiness in conjunction with dissociative experiences. Participants were 372 undergraduate college students, completed a package of psychological instruments, including the Morningness-Eveningness Questionnaire, Dissociative Experiences Scale, Insomnia Severity Index, and Epworth Sleepiness Scale. Using logistic regression models, direct relations of pathological dissociation with sleepiness, sleep quality and circadian preferences were investigated. Poor sleep quality and sleepiness significantly contributed to the variance of dissociative symptomatology. Although there was no substantial linear association between circadian preferences and pathological dissociation, having evening-type preferences of sleep was indirectly associated with higher dissociation mediated by poor sleep quality. Poor sleep quality and daytime sleepiness seems to be significant antecedents of pathological dissociation. Sleep chronotype preferences underlie this relational pattern that chronobiological characteristics seem to influence indirectly on dissociative tendency via sleep quality.

Effects of bright light exposure during daytime on peripheral clock gene expression in humans

Light is the strongest synchronizer controlling circadian rhythms. The intensity and duration of light change throughout the year, thereby influencing body weight, food preferences, and melatonin secretion in humans and animals. Although the expression of clock genes has been examined using human samples, it currently remains unknown whether bright light during the daytime affects the expression of these genes in humans. Therefore, we herein investigated the effects of bright light exposure during the daytime on clock gene expression in the hair follicular and root cells of the human scalp. Seven healthy men (20.4 ± 2.2 years old; 172.3 ± 5.8 cm; 64.3 ± 8.5 kg; BMI 21.7 ± 3.1 kg/m², mean ± SD) participated in this study. Subjects completed 3-day experimental sessions twice in 1 month during which they were exposed to bright and dim light conditions. The mRNA expression of Per1-3, Cry1-2, Rev-erb-α (Nr1d1), Rev-erb-β (Nr1d2), and Dec1 was analyzed using branched DNA probes. No significant changes were observed in the expression of Per1, Per2, Per3, Cry1, Cry2, Rev-erb-α (Nr1d1), or Dec1 following exposure to bright light conditions. However, the expression of Rev-erb-β (Nr1d2) tended to be stronger under bright light than dim light conditions. These results suggest that the bright light stimulus did not influence the expression of clock genes in humans. Long-lasting bright light exposure during the daytime may be required to change the expression of clock genes in humans.

Biological rhythms, metabolic syndrome and current depressive episode in a community sample

The purpose of this study was to assess the disruption in biological rhythms and metabolic syndrome (MetS) in individuals with depressive episode. This was a cross-sectional, population-based study with a representative sample of 905 young adults. Current depressive episode were confirmed by a psychologist using the Mini International Neuropsychiatric Interview (MINI)-Plus. Self-reported biological rhythms were assessed using the Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN). MetS was defined using modified NCEP/ATPIII criteria. Significant main effects of current depressive episode (p<0.001, η(2)=0.163) and MetS (p=0.001, η(2)=0.011) were observed on total BRIAN score. There was a significant interaction between depression and MetS in total biological rhythm scores (p=0.002, η(2)=0.011) as well as sleep (p=0.001, η(2)=0.016) and social domains (p<0.001, η(2)=0.014). In the depressive group, subjects with MetS had a higher disruption in total BRIAN scores (p=0.010), sleep domain (p=0.004), social domain (p=0.005) and in the eating pattern domain approached the level of significance (p=0.098), when compared to subjects with no MetS. The results of the present study showed that self-reported disruptions in biological rhythms are associated with key components of the MetS in community adults with MDD. The understanding of the complex interactions between biological rhythms, MetS and depression are important in the development of preventive and therapeutic strategies.

Demonstration of a day-night rhythm in human skeletal muscle oxidative capacity

OBJECTIVE

A disturbed day-night rhythm is associated with metabolic perturbations that can lead to obesity and type 2 diabetes mellitus (T2DM). In skeletal muscle, a reduced oxidative capacity is also associated with the development of T2DM. However, whether oxidative capacity in skeletal muscle displays a day-night rhythm in humans has so far not been investigated.

METHODS

Lean, healthy subjects were enrolled in a standardized living protocol with regular meals, physical activity and sleep to reflect our everyday lifestyle. Mitochondrial oxidative capacity was examined in skeletal muscle biopsies taken at five time points within a 24-hour period.

RESULTS

Core-body temperature was lower during the early night, confirming a normal day-night rhythm. Skeletal muscle oxidative capacity demonstrated a robust day-night rhythm, with a significant time effect in ADP-stimulated respiration (state 3 MO, state 3 MOG and state 3 MOGS, p < 0.05). Respiration was lowest at 1 PM and highest at 11 PM (state 3 MOGS: 80.6 ± 4.0 vs. 95.8 ± 4.7 pmol/mg/s). Interestingly, the fluctuation in mitochondrial function was also observed in whole-body energy expenditure, with peak energy expenditure at 11 PM and lowest energy expenditure at 4 AM (p < 0.001). In addition, we demonstrate rhythmicity in mRNA expression of molecular clock genes in human skeletal muscle.

CONCLUSIONS

Our results suggest that the biological clock drives robust rhythms in human skeletal muscle oxidative metabolism. It is tempting to speculate that disruption of these rhythms contribute to the deterioration of metabolic health associated with circadian misalignment.

Long-term effects of cognitive therapy on biological rhythms and depressive symptoms: A randomized clinical trial

OBJECTIVE

To evaluate the effect of cognitive therapy on biological rhythm and depressive and anxious symptoms in a twelve-month follow-up period. In addition, correlations between the reduction of depression and anxiety symptoms and the regulation of biological rhythm were observed.

METHODS

This was a randomized clinical trial with young adults from 18 to 29 years of age who were diagnosed with depression. Two models of psychotherapy were used: Cognitive Behavioral Therapy (CBT) and Narrative Cognitive Therapy (NCT). Biological rhythm was assessed with the Biological Rhythm Interview of Assessment in Neuropsychiatry (BRIAN). Severity of depressive and anxious symptoms was assessed by the Hamilton Depression Rating Scale (HDRS) and the Hamilton Anxiety Rating Scale (HARS), respectively. The sample included 97 patients who were divided within the protocols of psychotherapy.

RESULTS

There was a significant reduction in depressive and anxious symptoms (p<0.001) and an increase on regulation of biological rhythm (p<0.05) at the twelve-month follow-up. Moreover, we showed a positive correlation between the reduction of depressive symptoms and regulation of biological rhythm (r=0.638; p<0.001) and between the reduction of anxious symptoms and regulation of biological rhythm (r=0.438; p<0.001).

CONCLUSION

Both models showed that cognitive therapy was effective on the reduction of depressive and anxious symptoms and on the regulation of biological rhythm at a twelve-month follow-up evaluation. This study highlights the association between biological rhythm and symptoms of depression and anxiety.

LIMITATION

We did not assess genetic, hormonal or neurochemical factors and we did not include patients under pharmaceutical treatment or those with severe symptomatology.

Biological rhythms in bipolar and depressive disorders: A community study with drug-naïve young adults

AIM

To assess biological rhythm disruptions among drug-naïve young adults with bipolar disorder (BD), major depressive disorder (MDD), and community controls.

METHODS

This was a cross-sectional study nested in a population-based study. BD and MDD were diagnosed using the Structured Clinical Interview for DSM-IV. Biological rhythm disruptions were assessed using the Biological Rhythm Interview of Assessment in Neuropsychiatry (BRIAN).

RESULTS

Two hundred seventeen subjects were assessed (49 BD, 74 MDD, and 94 community controls). Biological rhythm disruption was higher in subjects with BD (40.32±9.92; p<0.001) and MDD (36.23±8.71; p<0.001) than community controls (27.67±6.88). Subjects with BD had a higher BRIAN total score (p=0.028) and higher disruption in sleep/social domains (p=0.018) as compared to MDD. In addition, the BRIAN scores were higher in current MDD, euthymic BD, and BD in current episode group, as compared to community controls.

LIMITATION

Cross-sectional design. Absence of assessment of biomarkers of biological rhythms.

CONCLUSION

Bipolar disorder and major depressive disorder are associated with disruption in biological rhythm. In addition, disruption in sleep/social rhythms is higher in subjects with BD when compared to subjects with MDD. We also verified biological rhythm disruption in subjects with BD during euthymic status, but not in remitted MDD. Regulation of biological rhythm may be a means to identify patients with mood disorders and potentially differentiate MDD from BD.

Temporal changes in calcium-binding proteins in the medial geniculate nucleus of the monkey Sapajus apella

The subdivisions of the medial geniculate complex can be distinguished based on the immunostaining of calcium-binding proteins and by the properties of the neurons within each subdivision. The possibility of changes in neurochemistry in this and other central auditory areas are important aspects to understand the basis that contributing to functional variations determined by environmental cycles or the animal's cycles of activity and rest. This study investigated, for the first time, day/night differences in the amounts of parvalbumin-, calretinin- and calbindin-containing neurons in the thalamic auditory center of a non-human primate, Sapajus apella. The immunoreactivity of the PV-IR, CB-IR and CR-IR neurons demonstrated different distribution patterns among the subdivisions of the medial geniculate. Moreover, a high number of CB- and CR-IR neurons were found during day, whereas PV-IR was predominant at night. We conclude that in addition to the chemical heterogeneity of the medial geniculate nucleus with respect to the expression of calcium-binding proteins, expression also varied relative to periods of light and darkness, which may be important for a possible functional adaptation of central auditory areas to environmental changes and thus ensure the survival and development of several related functions.

Melatonin and cortisol profiles in patients with pituitary tumors

The optic tract section at the optic chiasm is expected to disturb the suprachiasmatic nucleus (SCN) rhythm, circadian rhythm and melatonin secretion rhythms in humans, although detailed studies have never been conducted. The aim of this paper was to describe melatonin and cortisol profiles in patients with a pituitary tumor exerting optic chiasm compression. Six patients with pituitary tumors of different size, four of whom had significant optic chiasm compression, were examined. In each brain, MRI, an ophthalmological examination including the vision field and laboratory tests were performed. Melatonin and cortisol concentrations were measured at 22:00 h, 02:00 h, 06:00 h, and 10:00 h in patients lying in a dark, isolated room. One of the four cases with significant optic chiasm compression presented a flattened melatonin rhythm. The melatonin rhythm was also disturbed in one patient without optic chiasm compression. Larger tumors may play a role in the destruction of neurons connecting the retina with the suprachiasmatic nucleus (SCN) and breaking of basic way for inhibiting effect to the SCN from the retina.

Biological rhythm differences and suicidal ideation in patients with major depressive disorder

BACKGROUND

Suicidal behavior has been reported to be associated with seasonality and chronotype. However, no study has reported the suicidality according to chronotype and seasonality in patients with major depressive disorder (MDD). This study evaluated the relationship of suicidality and biological rhythm in patients with MDD.

METHODS

A total of 120 patients with MDD participated. We evaluated their seasonal patterns, chronotypes (morningness, wake up early and are at their best during the first part of the day; eveningness, feel best and most alert during late hours), suicidal ideations, and other clinical variables including symptom severity.

RESULTS

Patients with seasonality showed significantly higher suicidal ideation than patients without seasonality. Compared to morning-type participants, the evening-type participants showed higher suicidality. Suicidal ideation was positively correlated with eveningness tendencies and hypomanic personality traits.

LIMITATIONS

First, we did not analyze the causal relationship between biological rhythm and suicidality. Secondly, suicidal ideation does not in most cases reflect an actual attempt. Lastly, we did not categorize seasonal pattern into summer or winter type.

CONCLUSIONS

Our findings suggest that biological rhythm is significantly associated with suicidal ideation in patients with MDD.

Effects of cognitive psychotherapy on the biological rhythm of patients with depression

BACKGROUND

Stability between internal and external biological regulators are essential to stable mood states. However, the literature needs studies investigating the effect of brief psychotherapies in the biological rhythm regularization.

OBJECTIVE

To verify the capacity regulation of biological rhythms in two models of brief psychotherapy for the remission of depressive symptoms.

METHODS

We conducted a randomized clinical trial with young adults aged 18-29 years old who met diagnostic criteria for depression according to the Structured Clinical Interview for DSM (SCID). In order to evaluate the biological rhythm the Biological Rhythm of assessment in Neuropsychiatry (BRIAN) interview was used; whereas the severity of depression was assessed by the Hamilton Depression Rating Scale (HDRS). The psychotherapy models consisted of two cognitive psychotherapies: Cognitive Narrative Therapy (CNT) and Cognitive-Behavioral Therapy (CBT).

RESULTS

The sample consisted of 97 randomized into two models of brief psychotherapy. The patients regulated the biological rhythm from baseline to post-intervention (p=.001) and follow up (p=.003). We also found a positive moderate correlation between biological rhythm regularization and remission of the depressive symptoms (r=.594; p<.001).

CONCLUSION

The two models of brief psychotherapies were effective in the remission of depressive symptoms as well as the regulation of biological rhythms in the follow-up of 6 months.

LIMITATIONS

We did not assess genetic, hormonal and neurochemical factors. Also, we did not include patients in pharmaceutical treatment, and with severe symptomatology.

A dynamic model for functional mapping of biological rhythms

Functional mapping is a statistical method for mapping quantitative trait loci (QTLs) that regulate the dynamic pattern of a biological trait. This method integrates mathematical aspects of biological complexity into a mixture model for genetic mapping and tests the genetic effects of QTLs by comparing genotype-specific curve parameters. As a way of quantitatively specifying the dynamic behavior of a system, differential equations have proven to be powerful for modeling and unraveling the biochemical, molecular, and cellular mechanisms of a biological process, such as biological rhythms. The equipment of functional mapping with biologically meaningful differential equations provides new insights into the genetic control of any dynamic processes. We formulate a new functional mapping framework for a dynamic biological rhythm by incorporating a group of ordinary differential equations (ODE). The Runge-Kutta fourth order algorithm was implemented to estimate the parameters that define the system of ODE. The new model will find its implications for understanding the interplay between gene interactions and developmental pathways in complex biological rhythms.