Chronotype and its relationship with sleep disorders in children with attention deficit hyperactivity disorder

Chronotype can be classified as morningness types, people who prefer morning hours for their physical and mental activities; eveningness types, people who prefer the afternoon or evening hours; and intermediate types, those who show characteristics of both morningness and eveningness types. Attention deficit hyperactivity disorder (ADHD) has been linked with disturbances in chronotype, particularly increased eveningness. Despite the possibility of an association between chronotypes, sleep disturbances and ADHD symptoms, there is little evidence of this association considering the child population. The purpose of this study was to examine chronotype preferences in children aged between 7 and 12 years who were diagnosed as having ADHD in the context of sleep disturbances. The Schedule for Affective Disorders and Schizophrenia for School Age Children-Present and Lifetime Version, Conner’s Rating Scales, Children’s Sleep Habit Questionnaire and Children’s Chronotype Questionnaire were used for the evaluation of children with ADHD and healthy controls. The ADHD group was 73% combined-type, and the eveningness scores of the ADHD group (n = 52) were significantly higher than the control group (n = 52) (p < 0.01). There was a positive correlation between the higher scores of eveningness and total scores on resistance to sleep time (p < 0.09), respiratory problems during sleep and daytime sleepiness in the ADHD group. CSHQ total score was found to be a predictive factor for eveningness among children with ADHD (p < 0.01). These findings highlight possible reciprocal links between ADHD symptoms, sleep disturbances and chronotype in children aged 7–12 years, which might lead to individualized treatment options.     

Phase advance is an actimetric correlate of antidepressant response to sleep deprivation and light therapy in bipolar depression

The combination of total sleep deprivation (TSD) and light therapy (LT) in bipolar depression causes rapid antidepressant effects, and its mechanism of action has been hypothesized to involve the enhancement of all of the monoaminergic systems targeted by antidepressant drugs (serotonin, dopamine, norepinephrine). It is still unknown if the clinical effects are paralleled by changes in biological rhythms. In a before/after design of a study of biological correlates of response, 39 inpatients affected by Type I Bipolar Disorder whose current depressive episode was without psychotic features were treated for one week with repeated TSD combined with morning LT. Wrist actigraphy was recorded throughout the study. Two-thirds of the patients responded to treatment (50% reduction in Hamilton Depression score). Responders showed an increase in daytime activity, phase-advance of the activity-rest rhythm of 57 min compared to the pre-treatment baseline, and reduced nighttime sleep. Non-responders did not show significant changes in the parameters of their activity-rest rhythm. Phase advance of the activity-rest rhythm is an actimetric correlate of the antidepressant response to TSD and LT in bipolar depression. Results are consistent with the known effects of sleep-wake manipulations and neurotransmitter function on the suprachiasmatic nucleus.     

Chronotype preference matters for depression in youth

Morningness/eveningness (M/E) preference is an important circadian rhythm indicator with strong individual variation. M/E chronotype has been found to be correlated with depression in adults, yet the relationship is less clear in children and adolescents. Additionally, poor sleep quality is another commonly studied risk factor for depression. The aims of the present study are to investigate the independent effects of M/E chronotype on youth depression using both self-report and parental-report questionnaires. We also evaluated how poor sleep quality may affect the relationship through a mediating or moderating effect. In total, 2,139 students attending grades 1 to 7 participated in this study. They completed questionnaires regarding M/E chronotype, depression, and sleep quality. A total of 1,708 parents also participated and filled out parental-reports of emotional and behavioral problems of their children. The prevalence of self- and parental-report depression was 16.8% and 12.8% among young students, respectively. Overall, 15.4% of the students were the eveningness type. Being an eveningness type was independently associated with self-report depression after adjustment for poor sleep quality (OR = 1.86, 95% CI = 1.07–3.24). We also observed that poor sleep quality mediated the influence of M/E chronotype on self-report depression among students aged 7–13 years (p < 0.001). On the other hand, being an eveningness type was associated with a number of parental-report emotional and behavioral problems in the students, in addition to depression, although these associations become non-significant after adjusted for poor sleep quality. Our results demonstrate the importance of M/E chronotype on youth depression and poor sleep quality partly mediates this effect.     

Chronotype,gender and general health

Background: Light–dark alternation has always been the strongest external circadian “zeitgeber” for humans. Due to its growing technological preference, our society is quickly transforming toward a progressive “eveningness” (E), with consequences on personal circadian preference (chronotype), depending on gender as well. The aim of this study was to review the available evidence of possible relationships between chronotype and gender, with relevance on disturbances that could negatively impact general health, including daily life aspects. Methods: Electronic searches of the published literature were performed in the databases MEDLINE and Web of Science, by using the Medical Subject Heading (MeSH), when available, or other specific keywords. Results: Results were grouped into four general areas, i.e. (a) “General and Cardiovascular Issues”, (b) “Psychological and Psychopathological Issues”, (c) “Sleep and Sleep-Related Issues” and (d) “School and School-Related Issues”. (a) E is associated with unhealthy and dietary habits, smoking and alcohol drinking (in younger subjects) and, in adults, with diabetes and metabolic syndrome; (b) E is associated with impulsivity and anger, depression, anxiety disorders and nightmares (especially in women), risk taking behavior, use of alcohol, coffee and stimulants, psychopathology and personality traits; (c) E has been associated, especially in young subjects, with later bedtime and wake-up time, irregular sleep–wake schedule, subjective poor sleep, school performance and motivation, health-related quality of life; (d) E was associated with lowest mood and lower overall grade point average (especially for women). Conclusions: Eveningness may impact general health, either physical or mental, sleep, school results and achievements, especially in younger age and in women. The role of family support is crucial, and parents should be deeply informed that abuse of technological devices during night hours may lead to the immature adjustment function of children’s endogenous circadian pacemakers.     

Predictors of response to combined wake and light therapy in treatment-resistant inpatients with depression

ABSTRACT

There is growing evidence for combined chronotherapeutic interventions as adjunctive treatments for major depression. However, as the treatments can be demanding, we need to identify predictors of response. This study aimed to describe predictors of response, remission and deterioration in the short-term phase, as well as predictors of long-term response. The predictors investigated were gender, type of depression, severity of depression, treatment resistance, quetiapine use, general self-efficacy, educational level and positive diurnal variation. Follow-up data from 27 inpatients with moderate-to-severe depression participating in a chronotherapeutic intervention were analysed. As a supplement to standard treatment, they completed 3 wake therapy sessions in the first week, 30 min daily light treatment and sleep-time stabilisation in the entire 9-week study period. Patients had a significant decrease of depressive symptoms during the first 6 days measured by HAM-D6. At Day 6, 41% of the patients responded to the treatment and 19% fulfilled the criteria of remission. Deterioration by the end of wake therapy sessions was however not uncommon. In the short-term phase, mild degree of treatment resistance was associated with remission and low educational level associated with deterioration. Positive diurnal variation (mood best in the evening) was a predictor of both short-term and long-term response to combined wake and light therapy. Furthermore, patients with evening chronotypes (measured with morningness-eveningness score) were more responsive. Our results suggest that targeting the combined chronotherapeutic intervention at patients with positive diurnal variation and evening types is a viable option.     

Chronotype: implications for sleep quality in medical students

ABSTRACT

Medical students who suffer from poor sleep quality may be afflicted by distress. While the change of chronotype may improve sleep quality, few studies have focused on this association. The objective of this study is to analyze the effects of chronotype on sleep quality in medical students while controlling for confounding covariate factors. A cross-sectional survey on sleep quality was conducted among 5497 medical students. Sleep quality, chronotype, and lifestyle were measured according to the Pittsburgh Sleep Quality Index, Morningness-eveningness Questionnaire and Health-promoting Lifestyle Profile. Hierarchical logistic regression was conducted to analyze the influence of various factors, especially chronotype effect on sleep quality. Our results showed that the total score of sleep quality in evening-types was 5.43 ± 2.66, which was significantly higher than that in morning-types (3.88 ± 2.20, P < .001). Morning-type students (OR = 0.40, 95%CI = 0.29–0.55) and intermediate-type students (OR = 0.53, 95%CI = 0.41–0.69) had a lower risk of poor sleep quality compared to evening-types. The strongest predictor of sleep quality was chronotype while controlling for covariates (grade, gender, father’s educational level, mother’s educational level, internet addiction, mood state, midnight snack frequency, and health-promoting lifestyle profile). Based on the results, we believe that sleep quality among evening-type students may be improved by shifting to keep early hours.     

Effects of an adjunctive,chronotype-based light therapy in hospitalized patients with severe burnout symptoms - a pilot study

Light therapy is a well-established treatment option for seasonal affective disorders and is effective in reducing sleep problems and daytime fatigue. Symptoms of severe burnout include feelings of exhaustion and impaired sleep and mood. Thus, light therapy seems promising for burnout treatment. So far, light therapy effects in burnout were investigated in outpatient settings only, with inconclusive results. The present study targeted light therapy effects in an inpatient setting. Participants with severe burnout were recruited in two psychosomatic clinics and randomly assigned to a control group with multimodal psychiatric treatment or an add-on light treatment group. Participants in the latter group were additionally exposed to morning bright light (illuminance: 4246 lux, irradiance: 1802.81 µW.cm^?2) for 3 weeks, 30 minutes a day, timed to their chronotypes. Light effects on burnout symptoms, depression, well-being, daytime sleepiness, sleep quality, and attentional performance were measured twice (pre-/postintervention design). Adjunctive chronotype-based bright light therapy was well tolerated and improved burnout symptoms and well-being without additional effect on severity of depression. Furthermore, reduced daytime sleepiness, improved nighttime sleep quality, a sleep phase advance of 25 minutes, shortened sleep latency, less sleep disturbances and increased sleep duration were observed in the light treatment group. No group differences were found in attentional performance. Chronotype-based bright light therapy seems to be effective in improving burnout symptoms and sleep problems in patients with severe burnout symptoms. Further studies with larger sample sizes and objective measures of sleep are necessary to confirm these preliminary results before practical recommendations can be made.     

Chronotype and Breast Cancer Risk in a Cohort of US Nurses

The aim of this study was to examine the relation between chronotype and breast cancer risk. We analyzed the association between chronotype (definite morning type, probable morning type, probable evening type, definite evening type, or neither morning nor evening type) and breast cancer risk among 72 517 women in the Nurses’ Health Study II (NHS II). Chronotype was self-reported in 2009, and 1834 breast cancer cases were confirmed among participants between 1989 and 2007; a 2-yr lag period was imposed to account for possible circadian disruptions related to breast cancer diagnosis. Age- and multivariable-adjusted logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Participants who self-reported as neither morning nor evening type had a 27% increased risk of breast cancer (multivariable-adjusted OR?=?1.27, 95% CI?=?1.04–1.56), compared with definite morning types. None of the other chronotypes were significantly associated with breast cancer risk (multivariable-adjusted OR?=?0.99, 95% CI?=?0.87–1.12 for probable morning versus definite morning types; OR?=?0.96, 95% CI?=?0.84–1.09 for probable evening versus definite morning types; and OR?=?1.15, 95% CI?=?0.98–1.34 for definite evening versus definite morning types). Overall, chronotype was not associated with breast cancer risk in our study. A modestly increased risk among neither morning nor evening types may indicate circadian disruption as a potentially underlying mechanism; however, more studies are needed to confirm our results.     

Social jet lag: Sleep-corrected formula

Social jet lag is a term describing misalignment between social and biological times. In this article, it is argued that the currently used formula for social jet lag captures not only this misalignment, but also sleep debt resulting from sleep deprivation during workdays. It is proposed to adopt the sleep-corrected formula for social jet lag, which takes the form of the difference between the sleep onset on free days and workdays in the case of subjects with longer sleep and later (or equal) sleep onset on free days compared to workdays; it takes the form of the difference between the sleep offset on free days and workdays for subjects with longer sleep and earlier (or equal) sleep offset on workdays compared to free days.     

Sleep deprivation in depression stabilizing antidepressant effects by repetitive transcranial magnetic stimulation

Partial sleep deprivation (PSD) has a profound and rapid effect on depressed mood. However, the transient antidepressant effect of PSD - most patients relapse after one night of recovery sleep - is limiting the clinical use of this method. Using a controlled, balanced parallel design we studied, whether repetitive transcranial magnetic stimulation (rTMS) applied in the morning after PSD is able to prevent this relapse. 20 PSD responders were randomly assigned to receive either active or sham stimulation during the following 4 days after PSD. Active stimulation prolonged significantly (p < 0.001) the antidepressant effect of PSD up to 4 days. This finding indicates that rTMS is an efficacious method to prevent relapse after PSD.     

Association between depressive symptoms and morningness-eveningness,sleep duration and rotating shift work in Japanese nurses

Higher depressive symptoms have been reported in rotating shift workers compared with day workers. Depressive symptoms in adults who do not engage in night work have also been shown to be associated with chronotype and sleep duration. This study examines associations between depressive symptoms, morningness-eveningness (i.e. the degree to which people prefer to be active in the morning or the evening), sleep duration and rotating shift work. Japanese nurses (1252 day workers and 1780 rotating shift workers, aged 20–59) were studied using a self-administered questionnaire. The questionnaire covered depressive symptoms, morningness-eveningness, sleep habits and demographic characteristics of the participants. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to determine the levels of depressive symptoms. A Japanese version of the Morningness-Eveningness Questionnaire (MEQ) was used to measure morningness-eveningness. The CES-D score of shift workers was significantly (p < 0.05) higher than that of day workers. The MEQ score was significantly (p < 0.05) lower (i.e. greater eveningness) in shift workers than in day workers. Sleep duration on the day shift was significantly (p < 0.05) shorter in shift workers than in day workers. Simple linear regression revealed that the MEQ score, sleep duration on the day shift and current work shift (i.e. rotating shift work) were significantly (p < 0.05) associated with the CES-D score. Multivariate linear regression indicated that greater eveningness and shorter sleep duration were independently associated with higher CES-D scores, while rotating shift work was not. These associations between the MEQ score, the sleep duration and the CES-D score were also confirmed in both day workers and shift workers when the groups were analyzed separately. These results suggest that greater eveningness and shorter sleep duration on the day shift were independently associated with higher levels of depressive symptoms, which may explain associations between rotating shift workers and depressive symptoms. These findings have important implications for the development of novel strategies for preventing poor mental health in day workers and rotating shift workers.     

Sleep quality,chronotype and metabolic syndrome components in bipolar disorders during the remission period: Results from the FACE-BD cohort

Data on sleep or circadian abnormalities and metabolic disturbances in euthymic bipolar disorders are scarce and based on small sample sizes. The aim of this study was to explore the associations between sleep disturbances, chronotype and metabolic components in a large sample of euthymic patients with bipolar disorders (BD). From 2009 to 2015, 752 individuals with bipolar disorders from the FACE-BD cohort were included and assessed for sleep quality, chronotype and metabolic components. The Structured Clinical Interview for DSM-IV Axis I Disorders (SCID) was used to confirm the diagnosis of BD. Subjective sleep quality was measured with the Pittsburgh Sleep Quality Index and chronotype with the Composite Scale of Morningness. Sociodemographic and clinical characteristics, psychotropic treatment, psychiatric comorbidities and blood samples were collected. In our sample, 22.4% of individuals with BD presented with a metabolic syndrome, 53.7% had sleep disturbances, 25.4% were considered as having an evening chronotype and 12.6% as having a morning chronotype. Independently of potential confounders, euthymic patients with sleep disturbances had a higher abdominal circumference, and patients with evening chronotype had a significantly higher level of triglycerides. There was an association between evening chronotype and an increased atherogenic index of plasma (OR = 4.8, 95%CI = 1.6–14.7). Our findings contribute the scant literature on the relationship between sleep quality, chronotype and cardiometabolic components in euthymic individuals with BD and highlight the need to improve quality of sleep and patient education about healthier sleep-hygiene practices.     

Sleep pressure and time perception in university students

Here we aimed to investigate the association between poor quality of sleep, sleep debt during weekdays and the performance on an interval timing task, using the method of production of time and consisting on five sessions a day for nine days. The sleep of our volunteers was particularly restricted on weekdays. Moreover, later chronotype was associated with the need for compensation on weekends. Regarding the production of time, produced durations were consistently over-produced and there was an evident increase in the mean coefficient of variation (CV) from the wake-up morning to afternoon sessions, followed by a sharp decrease in the evening sessions. Importantly, CV was mainly determined by the interaction between MSFdiff, sleep duration on weekdays and age. In conclusion, our results indicate that when university students are under the effects of social jet lag and reduced sleep duration during weekdays, their performance in interval timing tasks may be compromised.     

The Relationship Between Breakfast Skipping,Chronotype, and Glycemic Control in Type 2 Diabetes

Breakfast skipping is associated with obesity and an increased risk of type 2 diabetes. Later chronotypes, individuals who have a preference for later bed and wake times, often skip breakfast. The aim of the study was to explore the relationships among breakfast skipping, chronotype, and glycemic control in type 2 diabetes patients. We collected sleep timing and 24-h dietary recall from 194 non-shift-working type 2 diabetes patients who were being followed in outpatient clinics. Mid-sleep time on free days (MSF) was used as an indicator of chronotype. Hemoglobin A1C (HbA_1C) values were obtained from medical records. Hierarchical linear regression analyses controlling for demographic, sleep, and dietary variables were computed to determine whether breakfast skipping was associated with HbA_1C. Additional regression analyses were performed to test if this association was mediated by chronotype. There were 22 participants (11.3%) who self-reported missing breakfast. Breakfast skippers had significantly higher HbA_1C levels, higher body mass indices (BMI), and later MSF than breakfast eaters. Breakfast skipping was significantly associated with higher HbA_1C values (B?=?0.108, p?=?0.01), even after adjusting for age, sex, race, BMI, number of diabetes complications, insulin use, depressive symptoms, perceived sleep debt, and percentage of daily caloric intake at dinner. The relationship between breakfast skipping and HbA_1C was partially mediated by chronotype. In summary, breakfast skipping is associated with a later chronotype. Later chronotype and breakfast skipping both contribute to poorer glycemic control, as indicated by higher HbA_1C levels. Future studies are needed to confirm these findings and determine whether behavioral interventions targeting breakfast eating or sleep timing may improve glycemic control in patients with type 2 diabetes.     

Late chronotype and high social jetlag are associated with burnout in evening-shift workers: Assessment using the Chinese-version MCTQshift

Chronotypes are associated with shift work tolerance and sleep in shift workers, and sleep mediates the impact of shift work on mental health. However, the role of chronotype in the association between shift work and mental health has not been clarified. In this study, we aimed to examine the association between chronotype and burnout in shift workers, using the validated Munich ChronoType Questionnaire for shift workers (MCTQ^shift). A total of 288 shift workers with irregular shift frequencies were recruited and completed the Chinese-version MCTQ^shift and the Morningness–Eveningness Questionnaire (MEQ). Chronotypes were assessed by the calculation of corrected mid-sleep time (MSF_SC) from mid-sleep time on free days (MSF) based on their exact shift schedules. Another 26 evening-shift nurses were monitored with actigraphy for at least two consecutive evening shifts and the following two free days. Burnout was evaluated using the Copenhagen Burnout Inventory. We found that MSF^E_SC, MSF^E and mid-sleep time on workdays (MSW^E) had normal distributions and correlated significantly with MEQ scores (r = ? 0.47, ?0.45 and ?0.47, respectively; all p < 0.001). MSW was more closely correlated with actigraphy-derived mid-sleep time on the free day before workdays than that on workdays (r = 0.61 and 0.48, respectively, p < 0.05). Sleep duration was significantly longer on workdays among evening-shift workers who slept late on workdays than those who slept early (β = 0.59, p < 0.001). After demographic and work characteristics were adjusted for in linear regression models, late chronotype and high social jetlag were associated with burnout scores in evening-shift workers. In conclusion, the Chinese-version MCTQ^shift is a valid tool for chronotype assessment. Interventions to improve sleep in shift workers should be tailored to chronotype due to variations in sleep behavior. Late chronotype may be an inherent feature of mental health problems, because the association with burnout was significant in both day workers in previous studies and shift workers.     

Moderation of genetic and environmental influences on diurnal preference by age in adult twins

Diurnal preference changes across the lifespan. However, the mechanisms underlying this age-related shift are poorly understood. The aim of this twin study was to determine the extent to which genetic and environmental influences on diurnal preference are moderated by age. Seven hundred and sixty-eight monozygotic and 674 dizygotic adult twin pairs participating in the University of Washington Twin Registry completed the reduced Morningness–Eveningness Questionnaire as a measure of diurnal preference. Participants ranged in age from 19 to 93 years (mean?=?36.23, SD?=?15.54) and were categorized on the basis of age into three groups: younger adulthood (19–35 years, n?=?1715 individuals), middle adulthood (36–64 years, n?=?1003 individuals) and older adulthood (65+ years, n?=?168 individuals). Increasing age was associated with an increasing tendency towards morningness (r?=?0.42, p?<?0.001). Structural equation modeling techniques parsed the variance in diurnal preference into genetic and environmental influences for the total sample as well as for each age group separately. Additive genetic influences accounted for 52%_[46–57%], and non-shared environmental influences 48%_[43–54%], of the total variance in diurnal preference. In comparing univariate genetic models between age groups, the best-fitting model was one in which the parameter estimates for younger adults and older adults were equated, in comparison with middle adulthood. For younger and older adulthood, additive genetic influences accounted for 44%_[31–49%] and non-shared environmental influences 56%_[49–64%] of variance in diurnal preference, whereas for middle adulthood these estimates were 34%_[21–45%] and 66%_[55–79%], respectively. Therefore, genetic influences on diurnal preference are attenuated in middle adulthood. Attenuation is likely driven by the increased importance of work and family responsibilities during this life stage, in comparison with younger and older adulthood when these factors may be less influential in determining sleep–wake timing. These findings have implications for studies aimed at identifying specific non-shared environmental influences, as well as molecular genetic studies aimed at identifying specific polymorphisms associated with diurnal preference.     

Chronotype,bed timing and total sleep time in seniors

Many older adults (seniors) experience problems with getting enough sleep. Because of the link between sleep and circadian rhythms, changes in bedtime lead to changes in the amount of sleep obtained. Although primarily determined genetically, chronotype changes with advancing age towards a more morning-type (M-type) orientation. In a 2006 study, we have found a linear relationship, by which the earlier a senior’s bedtime, the more sleep she/he will obtain. The aim of this study was to see whether this relationship differs for M-type seniors, as compared to seniors outside the M-type category. Retired seniors (n?=?954, 535?M, 410F, 65?years+, mean age 74.4?years) taking part in a telephone interview were divided into M-types and Other types (O-types) using the Composite Scale of Morningness (CSM). The relationship between bedtime and Total Sleep Time (TST), and between rise-time and TST, was tested using linear regression separately for M-types and O-types. For each participant, habitual bedtime, rise-time and total Sleep Time (TST) [after removing time spent in unwanted wakefulness] were obtained using a telephone version of the Sleep Timing Questionnaire (STQ). Both chronotype groups showed a significant linear relationship between bedtime and TST (p?<?0.001); with earlier bedtimes leading to more TST (M-type 5.6?min; O-type 4.4?min per 10?min change [slope difference p?=?0.05]); and an opposite relationship between rise-time and TST with earlier rise-times leading to less TST (M-type 6.7?min; O-type 4.2?min per 10?min change [slope difference p?=?0.001]). M-types retired to bed 56?min earlier (p?<?0.001), awoke 93?min earlier (p?<?0.001) and obtained 23?min less TST (p?<?0.001) than O-types. In conclusion, both chronotypes showed TST to be related in a linear way to bedtime and rise-time; the overall shorter TST in M-types was due to them rising 93?min earlier, but only retiring to bed 56?min earlier than O-types; as well as having a steeper rise-time versus TST relationship.     

The relationship between chronotype,sleep disturbance,severity of fibromyalgia,and quality of life in patients with fibromyalgia

ABSTRACT

Patients with fibromyalgia (FM) report high levels of sleep disturbance and chronic diffuse musculoskeletal pain. These patients experience diminished quality of life (QoL) due to pain and other comorbidities. Chronotype preferences have been suggested as a potential factor connecting increased severity of FM, sleep disturbances, and poor overall QoL. The present study is the first study examining the possible association between chronotype preferences, sleep disturbance, severity of FM, and QoL in patients with FM.

One hundred drug-free patients diagnosed with FM participated in this cross-sectional study. Of them, 79 (79%) were females and 21 (21%) were males. The mean age was 41.65 ± 9.17 years (range: 21–62 years). The severity of FM symptoms, chronotype preferences, and QoL was evaluated using the Fibromyalgia Impact Questionnaire (FIQ), Morningness-Eveningness Questionnaire (MEQ), and World Health Organization Questionnaire on Quality of Life: Short Form (WHOQOL-BREF). The participants’ anxiety/depressive symptoms and sleep problems were assessed using the Hospital Anxiety and Depression Scale (HADS) and Pittsburgh Sleep Quality Index (PSQI).

The participants were classified according to their MEQ scores as evening type (score: 16–41), neither type (score: 42–58), and morning type (score: 59–86). It was found that there were significant differences in the FIQ score between the three groups (p < .001). It was determined that the total PSQI score was significantly higher in the evening type than the other two types (p < .05). It was found that there were significant differences in the general health, physical health, psychological, and environmental domain scores of the WHOQOL-BREF between the three groups (p < .05). It was detected that there were significant correlations between MEQ scores, WHOQOL-BREF subscale scores, FIQ scores, HADS-A and HADS-D scores, and PSQI scores. According to hierarchical regression analysis, eveningness preference explained an additional 21.9% of the variation in FM severity, thereby causing a statistically significant change in R-squared.

Our results indicated that eveningness preference was directly related to increased FM symptom severity and poorer QoL. Based on these findings, neglecting to take chronotype preference into account may not result in optimal response to standard treatment for some patients with FM.