Social Rhythm Metric Research Articles

An exploratory pilot study on social rhythm regularity, and its associations with sleep, circadian, affective, and alcohol use outcomes in late adolescents.

The current exploratory pilot study examined whether social rhythm regularity, as measured by a social rhythm metric, was associated with: (1) the regularity of circadian rhythms and/or sleep regularity metrics; and (2) sleep quality, affective function and alcohol use. Late adolescents (18-22 years old) who drink alcohol (n = 36; 61.1% female, Mage = 21.26 years) completed a 14-day ecological momentary assessment protocol, wore a wrist actigraph for 14 days, and completed two overnight visits (Thursday and Sunday) to assess dim light melatonin onset. Sleep regularity metrics included standard deviation, composite phase deviation, social jet lag and inter-daily stability. We used dim light melatonin onset data to calculate the stability of the circadian phase (Sunday minus Thursday). Participants completed surveys and ecological momentary assessments that assessed global and daily sleep quality, affective function, and alcohol use. Correlational analysis and robust regression modelling were used. More regular social rhythms were associated with higher regularities of mid-sleep timing based on standard deviations, but were not associated with other sleep regularity metrics or stability of the circadian phase. More regular social rhythms were associated with better sleep quality, but were not associated with affective function or alcohol use. Social rhythm regularity is a unique construct compared with existing sleep quality metrics. In contrast with the social zeitgeber hypothesis, social rhythm regularity was not associated with circadian rhythm regularity measured by dim light melatonin onset. However, social rhythm regularity may be an under-recognized contributor to better sleep quality.

Social rhythm and implications on functionality of patients after stroke

ABSTRACT The study aimed to assess the regularity, intensity, frequency, and period of activities comprising social rhythm and associate them with the functionality of stroke patients. The sample consisted of 73 patients (41 men and 32 women) with a mean age of 60 years (±10). Social rhythm was assessed by Social Rhythm Metric (SRM) and Activity Level Index (ALI). The functionality was evaluated using the International Classification of Functioning, Disability, and Health (ICF). Data were analyzed using Student’s t-test, ANOVA, and Chi-square test. The mean SRM was 5.1 ± 0.9, and ALI was 58.3 ± 14.9. Notably, 40% of the patients exhibited both low regularity and low intensity of activities. Six SRM activities, performed with low frequency (going outside, starting work, exercising, snacking, watching other TV programs, and going home), exhibited a tendency to have periods that deviated from the expected 24-hour daily cycle. ICF domains most associated with SRM were: d2-General tasks and demands, d3-Communication, d4-Mobility, d5-Self care, d8-Major life areas, and d9-Community, social and civic life. The results indicated changes in social rhythm with implications for patient functionality. Screening for disruptions in social rhythm could be part of the functional assessment during the rehabilitation process for post-stroke patients.

Behavioral-Social Rhythms and Cardiovascular Disease Risk in Retired Night Shift Workers and Retired Day Workers.

Stability in the timing of key daily routine behaviors such as working/doing housework, sleeping, eating, and engaging in social interactions (i.e., behavioral-social rhythms) contributes to health. This study examined whether behavioral-social rhythms were associated with cardiovascular disease (CVD) risk factors in retired night shift workers and retired day workers and explored whether past night shift work exposure moderated this association. A total of 154 retired older adults participated in this study. Multiple logistic regression models were used to examine associations between behavioral-social rhythms and CVD risk factors. Independent variables included Social Rhythm Metric (SRM)-5 score and actigraphy rest-activity rhythm intradaily variability (IV) and interdaily stability (IS). Dependent variables were metabolic syndrome prevalence and its five individual components. More regular behavioral-social rhythms were associated with lower odds of prevalent metabolic syndrome (SRM: odds ratio [OR] = 0.57, 95% confidence interval [CI] = 0.35-0.88; IV: OR = 4.00, 95% CI = 1.86-8.58; IS: OR = 0.42, 95% CI = 0.24-0.73) and two of its individual components: body mass index (SRM: OR = 0.56, 95% CI = 0.37-0.85; IV: OR = 2.84, 95% CI = 1.59-5.07; IS: OR = 0.42, 95% CI = 0.26-0.68) and high-density lipoprotein cholesterol (SRM: OR = 0.49, 95% CI = 0.30-0.80; IV: OR = 2.49, 95% CI = 1.25-4.96; IS: OR = 0.35, 95% CI = 0.19-0.66). Past shift work history did not moderate the association between behavioral-social rhythms and metabolic syndrome. Behavioral-social rhythms were related to CVD risk factors in retired adults regardless of prior night shift work exposure. Older retired workers may benefit from education and interventions aiming to increase behavioral-social rhythm regularity.

0693 A Characterization of Social Rhythms in Obsessive-Compulsive Disorder

Abstract Introduction Recent evidence has shown that obsessive-compulsive disorder (OCD) is linked to shifts in biologically driven sleep timing, indicating the role of biological rhythms within the disorder. Specifically, initial evidence suggests that biological disruptions in OCD may play a role in symptom severity and OCD treatment efficacy. Germane to the study of biological rhythmicity is the consideration of social rhythms within OCD. Disruptions in social rhythmicity are found in other psychological disorders associated with biological rhythm vulnerabilities (i.e., Bipolar Spectrum Disorder, Depression, and Post-Traumatic Stress Disorder.) Given the shared features and high rates of comorbidity between OCD and these disorders, it is reasonable that social rhythm disruptions would be found in OCD as well. As no research to date has examined this, we sought to examine the regularity and distribution of social rhythm in individuals with clinically significant obsessive-compulsive symptoms. Further, we examined the role of affect and symptom severity across OCD subtypes. Methods 19 adults meeting criteria for a primary diagnosis of obsessive-compulsive disorder completed the Social Rhythm Metric at home for a period of 7 days. As part of a larger study, participants completed measures of sleep (Pittsburgh Sleep Quality Index), affect (Positive and Negative Affect Schedule), and obsessive-compulsive symptom severity and subtype (Obsessive-Compulsive Inventory) following diagnosis. Results We found the mean social rhythmicity in those with an OCD diagnosis to be 3.05 (SD=1.14.), similar to means found previously in other psychiatric disorders such as Bipolar Spectrum Disorder and Post-Traumatic Stress Disorder. Individuals with OCD who also reported delayed bedtimes were shown to have significantly lower social rhythmicity (p=.005) than those without delayed bedtimes. Additionally, we found that social rhythmicity correlated similarly across OCD subtypes and was not strongly correlated with negative affect. Conclusion In the current study, we provide a preliminary characterization of social rhythmicity in those with OCD. Results suggest that social rhythm may play a role in OCD similar to bipolar disorder and further study is warranted. Overall, this study contributes to burgeoning research into the association between biological rhythms and OCD. Support (If Any)

Social rhythm regularity moderates the relationship between sleep disruption and depressive symptoms in veterans with post-traumatic stress disorder and major depressive disorder

ABSTRACTApproximately 50% to 80% of individuals with posttraumatic stress disorder (PTSD) also meet criteria for major depressive disorder (MDD). Sleep disturbance is a major concern in both PTSD and MDD, and is associated with poor treatment response, poor functional outcome and increased suicide risk. Social rhythm regularity, or the consistency of daily habitual behaviors, is theoretically linked to circadian rhythms and may be disturbed in both PTSD and MDD. The present study examined the relationship between social rhythm regularity, sleep disruption and MDD and PTSD symptoms in a sample of veterans with comorbid PTSD and MDD. Baseline data were obtained from 56 male veterans who met DSM-IV criteria for PTSD and MDD. Veterans completed the Social Rhythm Metric (SRM), a self-report questionnaire that assesses the regularity of routines by determining how regularly individuals completed 17 different types of activities. In a linear regression model, increased minutes awake after sleep onset (WASO) was a significant predictor of increased depression scores on the Hamilton Rating Scale for Depression (p < .05). SRM scores did not significantly predict depressive symptoms, however the interaction of WASO and SRM significantly predicted depressive symptoms (p = <.05), with significant relationships found at SRM scores less than 3.62. Neither minutes awake after sleep onset, SRM scores, nor their interaction was associated with PTSD symptom severity. Social and possibly circadian rhythm regularity may represent a risk or resilience factor for individuals with comorbid PTSD and MDD. Findings highlight the importance of exploring the interactions of sleep and social/circadian rhythms in depression in order to inform continued treatment development.

Short form of the Social Rhythm Metric: a tool to evaluate the social and functional impact on stroke patients

Social Rhythm Metric (SRM) is a self-administered instrument to specifically measure the regularity of the occurrence of several daily activities. This study aimed to establish a short form of the SRM to assess the social rhythm of stroke patients. The sample consisted of 84 patients, mean age 60 years (± 10), and injury time of 19 months (± 22). For seven consecutive days, patients recorded the time of day at which all 17 SRM activities were performed. Data analysis was conducted using factor analysis. SRM activities were distributed in three forms: the first and second involving 6 activities and a third form with 3 activities. The first form consisted of the following activities: get out of bed, first contact with a person, morning beverage, breakfast, evening TV news program and bedtime; and obtained the highest ALI (Activity Level Index) and SRM scores (29 and 6, respectively). When confirmatory factorial analysis was performed, there was an improvement in the goodness-of-fit statistics only for the first short form of SRM: χ2/df value was below 3; RMSEA and values of CFI and TLI increased greatly, reaching approximately the appropriate values for the model adjustment (RMSEA = 0.08, CFI = 0.92 and TLI = 0.81). The first form was considered the appropriate short form to assess SRM in stroke patients. This instrument may be useful in neurological rehabilitation and evaluating the social and functional impact of this disease.

Associations between period 3 gene polymorphisms and sleep- /chronotype-related variables in patients with late-life insomnia

ABSTRACTA variable number tandem repeat polymorphism (VNTR) in the period 3 (PER3) gene has been associated with heritable sleep and circadian variables, including self-rated chronotypes, polysomnographic (PSG) variables, insomnia and circadian sleep-wake disorders. This report describes novel molecular and clinical analyses of PER3 VNTR polymorphisms to better define their functional consequences. As the PER3 VNTR is located in the exonic (protein coding) region of PER3, we initially investigated whether both alleles (variants) are transcribed into messenger RNA in human fibroblasts. The VNTR showed bi-allelic gene expression. We next investigated genetic associations in relation to clinical variables in 274 older adult Caucasian individuals. Independent variables included genotypes for the PER3 VNTR as well as a representative set of single nucleotide polymorphisms (SNPs) that tag common variants at the PER3 locus (linkage disequilibrium (LD) between genetic variants < 0.5). In order to comprehensively evaluate variables analyzed individually in prior analyses, dependent measures included PSG total sleep time and sleep latency, self-rated chronotype, estimated with the Composite Scale (CS), and lifestyle regularity, estimated using the social rhythm metric (SRM). Initially, genetic polymorphisms were individually analyzed in relation to each outcome variable using analysis of variance (ANOVA). Nominally significant associations were further tested using regression analyses that incorporated individual ANOVA-associated DNA variants as potential predictors and each of the selected sleep/circadian variables as outcomes. The covariates included age, gender, body mass index and an index of medical co-morbidity. Significant genetic associations with the VNTR were not detected with the sleep or circadian variables. Nominally significant associations were detected between SNP rs1012477 and CS scores (p = 0.003) and between rs10462021 and SRM (p = 0.047); rs11579477 and average delta power (p = 0.043) (analyses uncorrected for multiple comparisons). In conclusion, alleles of the VNTR are expressed at the transcript level and may have a functional effect in cells expressing the PER3 gene. PER3 polymorphisms had a modest impact on selected sleep/circadian variables in our sample, suggesting that PER3 is associated with sleep and circadian function beyond VNTR polymorphisms. Further replicate analyses in larger, independent samples are recommended.

Correlates and prognostic relevance of sleep irregularity in inter-episode bipolar disorder

ObjectivesSleep–wake disturbances, such as sleep irregularity, are common in bipolar disorder. Early studies suggest that sleep irregularity is associated with mood symptoms in bipolar disorder, but little research has been conducted to identify other correlates of sleep irregularity. We investigated the relationship between sleep irregularity and sleep quality, social rhythms, eveningness, sleep-related cognitions and behaviors, and past and future mood episodes in 84 patients with inter-episode bipolar I or II disorder. MethodsThis is a retrospective and prospective, naturalistic follow-up study. The Expanded Consensus Sleep Diary, Pittsburgh Sleep Quality Index (PSQI), Social Rhythm Metric (SRM-II-5), Composite Scale of Morningness (CSM), Dysfunctional Beliefs and Attitudes About Sleep Scale (DBAS-16), and Sleep Hygiene Practice Scale (SHPS) were administered. The Square Successive Difference (SSD), derived from a week-long sleep diary, was used as an index of sleep irregularity. Multilevel modeling analysis, which adjusts for biases in parameter estimates, was used to minimize the impact of missing data. Bonferroni correction was performed to account for multiple testing. ResultsHigher SSD scores of sleep diary variables were significantly associated with higher PSQI, SRM-II-5, DBAS-16, and SHPS scores. Irregularity in total sleep time was related to more depressive episodes in the past 5years (p=.002), while irregularity in wake after sleep onset predicted the onset of depressive episodes over the next 2years (p=.002). ConclusionSleep irregularity was associated with poor sleep quality, irregular social rhythms, dysfunctional sleep-related cognitions and behaviors, and greater number of depressive episodes in bipolar disorder.

Low social rhythm regularity predicts first onset of bipolar spectrum disorders among at-risk individuals with reward hypersensitivity.

The social zeitgeber model (Ehlers, Frank, & Kupfer, 1988) suggests that irregular daily schedules or social rhythms provide vulnerability to bipolar spectrum disorders. This study tested whether social rhythm regularity prospectively predicted first lifetime onset of bipolar spectrum disorders in adolescents already at risk for bipolar disorder based on exhibiting reward hypersensitivity. Adolescents (ages 14-19 years) previously screened to have high (n = 138) or moderate (n = 95) reward sensitivity, but no lifetime history of bipolar spectrum disorder, completed measures of depressive and manic symptoms, family history of bipolar disorder, and the Social Rhythm Metric. They were followed prospectively with semistructured diagnostic interviews every 6 months for an average of 31.7 (SD = 20.1) months. Hierarchical logistic regression indicated that low social rhythm regularity at baseline predicted greater likelihood of first onset of bipolar spectrum disorder over follow-up among high-reward-sensitivity adolescents but not moderate-reward-sensitivity adolescents, controlling for follow-up time, gender, age, family history of bipolar disorder, and initial manic and depressive symptoms (β = -.150, Wald = 4.365, p = .037, odds ratio = .861, 95% confidence interval [.748, .991]). Consistent with the social zeitgeber theory, low social rhythm regularity provides vulnerability to first onset of bipolar spectrum disorder among at-risk adolescents. It may be possible to identify adolescents at risk for developing a bipolar spectrum disorder based on exhibiting both reward hypersensitivity and social rhythm irregularity before onset occurs.

Social rhythm and other chronobiological findings in juvenile myoclonic epilepsy

We evaluated the correlation between chronobiological variables and characteristics of juvenile myoclonic epilepsy. Sample: 17 individuals epileptic outpatients and respective controls. Instruments: The Social Rhythm Metric for social zeitgebers, lux meter, and an ACT10® thermistor for activity–rest rhythm, light exposure, and peripheral body temperature. Regularity scores showed an inverse correlation with age at disease onset (r = −0.5; p < 0.05), but not with disease duration or stabilization time. A significant intergroup difference was recorded for mean diurnal peripheral temperature (p < 0.01) and activity amplitude (= 0.06). There was a correlation between activity and temperature means in both groups. These results underscore the relationship between epilepsy and the biological clock on a physiological level. Epilepsy, in turn, is influenced by the circadian rhythm, indicating the potential involvement of the body’s internal clock in the development of the disease or the seizure recurrence pattern.

Calculating the Social Rhythm Metric (SRM) and Examining Its Use in Interpersonal Social Rhythm Therapy (IPSRT) in a Healthy Population Study.

In psychiatry, the social zeitgeber theory argues that social life provides important social cues that entrain circadian rhythms. Disturbance of these social cues might lead do dis-entrainment of circadian rhythms and evoke somatic symptoms that increase the risk of mood disorders. In preventing and treating patients with bipolar disorders, the Interpersonal and Social Rhythm Therapy (IPSRT) relies on the Social Rhythm Metric (SRM) to (re)establish patients’ social cues and an re-entrain circadian rhythms. Since the SRM quantifies social rhythms that are derived from a patient’s interaction with a social environment, this contribution (a) calculates the SRM of the social environment of a representative healthy population study (n = 1249), (b) evaluates the robustness of the SRM as a quantifier of social rhythms by matching the scores of the pilot study, revealing the near absence of variance across population characteristics and investigation months—circadian rhythms need to be entrained for every month and for everyone—and (c) examines its use in IPSRT by relating high SRM-scores to lower psychological distress (p = 0.004) and low SRM-scores to higher social and emotional dysfunction (p = 0.018).

Relationship of Chronotype to Sleep, Light Exposure, and Work-Related Fatigue in Student Workers

Students who work during the school year face the potential of sleep deprivation and its effects, since they have to juggle between school and work responsibilities along with social life. This may leave them with less time left for sleep than their nonworking counterparts. Chronotype is a factor that may exert an influence on the sleep of student workers. Also, light and social zeitgebers may have an impact on the sleep-related problems of this population. This study aimed to document sleep, light exposure patterns, social rhythms, and work-related fatigue of student workers aged 19–21 yrs and explore possible associations with chronotype. A total of 88 student workers (mean ± SD: 20.18 ± .44 yrs of age; 36 males/52 females) wore an actigraph (Actiwatch-L; Mini-Mitter/Respironics,Bend, OR) and filled out the Social Rhythm Metric for two consecutive weeks during the school year. Also, they completed the Morningness-Eveningness Questionnaire (MEQ), Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and Occupational Fatigue Exhaustion/Recovery Scale (OFER). Repeated and one-way analyses of variance (ANOVAs), Pearson's chi-square tests, and correlation coefficients were used for statistical comparisons. Subjects slept an average of 06:28 h/night. Actigraphic sleep parameters, such as sleep duration, sleep efficiency, wake after sleep onset, and sleep latency, did not differ between chronotypes. Results also show that evening types (n = 17) presented lower subjective sleep quality than intermediate types (n = 58) and morning types (n = 13). Moreover, evening types reported higher levels of chronic work-related fatigue, exhibited less regular social rhythms, and were exposed to lower levels of light during their waking hours (between 2 and 11 h after wake time) as compared to intermediate types and morning types. In addition, exposure to light intensities between 100 and 500 lux was lower in evening types than in intermediate types and morning types. However, bright light exposure (≥1000 lux) did not differ between chronotypes. In conclusion, results suggest that student workers may constitute a high-risk population for sleep deprivation. Evening types seemed to cope less well with sleep deprivation, reporting poorer sleep quality and higher levels of work-related fatigue than intermediate types and morning types. The higher chronic work-related fatigue of evening types may be linked to their attenuated level of light exposure and weaker social zeitgebers. These results add credence to the hypothesis that eveningness entails a higher risk of health-impairing behaviors. (Author correspondence: luc.laberge@uqac.ca)

Desenvolvimento da versão breve da Escala de Ritmo Social

OBJETIVO: O objetivo deste trabalho é o estabelecimento de uma versão abreviada da Escala de Ritmo Social, com vistas à aplicação em pesquisa. MÉTODOS: Tomando como padrão-ouro a Escala de Ritmo Social de 17 itens, estabelecidas três versões breves a partir de três critérios diferentes. Comparados escores de regularidade e quantidade de atividades desenvolvidas em um período de uma semana de 167 sujeitos saudáveis, 25 portadores de epilepsia mioclônica juvenil e 16 portadores de transtorno depressivo. RESULTADOS: A versão breve de seis itens mostrou melhor concordância com relação ao padrão-ouro k = 0,51; p &lt; 0,001. A análise bivariada demonstrou significativa correlação entre a versão breve-6 e o padrão-ouro: (r = 0,87; p &lt; 0,001). Houve correlação com idade na versão breve-6 (r = 0,2; p &lt; 0,001), ainda mais significativa do que no padrão-ouro (r = 0,2; P &lt; 0,01). Na análise ANOVA, o grupo saudável apresentou escores mais altos de regularidade em ambas as escalas. Com relação à quantidade de atividades, o grupo saudável assemelhou-se ao dos portadores de epilepsia e o dos portadores de depressão apresentou médias mais baixas. CONCLUSÃO: A simplificação da escala diminui a porcentagem de itens não preenchidos e custo em material impresso e facilita a padronização. O processo envolveu cuidadosa análise da adequação do instrumento à cultura-alvo.

Cronotipo e implicações para sua utilização na fisioterapia em pacientes com acidente vascular encefálico

Na prática clínica, frequentemente o fisioterapeuta avalia e programa o tratamento do paciente sem levar em consideração a variação temporal de funções e comportamentos. O objetivo do estudo foi analisar a influência do cronotipo, padrão vigília-sono (qualidade do sono e sonolência excessiva) e regularidade do estilo de vida na determinação do horário de preferência para a prática de atividades física e mental em pacientes com acidente vascular encefálico (AVE). Participaram 42 pacientes (61±9 anos) no estágio crônico do AVE (18±21 meses) e 12 indivíduos saudáveis (53±6 anos) que responderam ao Questionário de Horne e Östberg (QHO), Índice de Qualidade do Sono de Pittsburgh (IQSP), Sonolência Excessiva de Epworth (SEE) e o Social Rhythm Metric (SRM). Foi questionado em qual horário os participantes preferiam realizar atividade física (exercícios) e mental (tarefas de raciocínio), considerando apenas seu bem-estar pessoal. Os dados foram analisados através do teste do χ2 e regressão múltipla. Dos pacientes avaliados, 93% eram matutinos, 64% apresentavam qualidade ruim do sono, 43% sonolência excessiva e 57% padrão irregular da rotina diária. Ao final da análise de regressão verificou-se que o cronotipo foi o único fator que teve influência no horário preferencial das atividades. Esses achados sugerem a necessidade da avaliação do cronotipo dos pacientes antes de se estabelecer um horário de atendimento na Fisioterapia.

Sleep quality and daily lifestyle regularity in workers with different working hours

The objective of this study was to assess subjective sleep quality and lifestyle regularity in daytime workers and shift workers. Studies concluding that sleep quality improved with greater regularity. However, there are no data in the literature related to workers. The sample was composed of 141 male workers (42 daytime workers and 99 shift workers) with 42.56 ± 5.66 years of age. Protocols: informed consent form; identification record; Pittsburgh Sleep Quality Index (PSQI), and a shortened 5-item version of the Social Rhythm Metric (SRM-5). Student's t-test for independent samples and Spearman's nonparametric correlation test were used. There was bad sleep quality (6.23 ± 3.3) and daily lifestyle irregularity (2.36 ± 0.8) for 141 workers. There was good sleep quality for daytime workers (4.74 ± 2.68) and bad sleep quality for shift workers (6.86 ± 3.31). There are daily lifestyle irregularities for both groups (for daytime workers 2.23 ± 0.55 and for shift workers 2.41 ± 0.94). There was no significant correlation between the SRM-5 and overall PSQI scores. In shift work, the regularity of daily activities does not seem to be the main factor in determining sleep quality.

Behavioral Regularity in Infancy Predicts Lower Anxiety Years Later

Back to table of contents Previous article Next article Clinical & Research NewsFull AccessBehavioral Regularity in Infancy Predicts Lower Anxiety Years LaterMark MoranMark MoranSearch for more papers by this authorPublished Online:3 Sep 2010https://doi.org/10.1176/pn.45.17.psychnews_45_17_030AbstractLack of regularity in sleeping, eating, and play routines in infancy appears to be associated with risk for anxiety in childhood.Infants with irregular patterns of sleeping, eating, and playing were significantly more likely to experience symptoms of anxiety more than a decade later, according to a prospective study of 59 children followed for 13 years beginning at age 1 month. The report was published online in the July Psychiatry Research.“The study indicates there are long-term implications for early behavioral regularity,” co-author Linnea Burk, Ph.D., of the Wisconsin Psychiatric Institute and Clinics, told Psychiatric News. “Clinicians have long advocated for predictable care and sleep schedules for children, and this study provides clear support that these steps are not only important in the short run, while the children are young, but also to long-term outcomes in adolescence.”Beginning in 1990 and 1991 as part of the Wisconsin Study of Families and Work, parents of 59 infants completed a diary tool called the Baby Social Rhythm Metric (Baby SRM), devised by the researchers to document lifestyle routines and sleep patterns a week at a time. The diary was a structured instrument that required parents to write down the starting time for each of four other major daily events in the infant's life—feeding, playing, diaper changing, and receiving comfort. There were 30 baby girls and 29 baby boys.(The Wisconsin Study of Families and Work is a much larger prospective study of child development that has yielded a number of published papers. Information about the study is posted at <www.wsfw.us>.)Follow-up information was collected on “sociability” at ages 4 months and 12 months as measured by the Infant Behavior Questionnaire, and on symptoms of depression and anxiety in children up to age 13. A measure of children's “directed attention”—reflecting the ability to focus attention on specific tasks and environmental exploration—was obtained from videotaped observations of a two-hour home visit when children were 4.5 years of age.Separately, and only after follow-up data were gathered, an algorithm was developed that cast the four specified events measured in the Baby SRM into 12 two-hour segments covering the 24-hour day. The resulting metric related to how spread out around the clock the events were (reflecting a low SRM score and a high degree of irregularity) or the extent to which particular times of day predominated for each of the events (reflecting a high SRM score and a high degree of regularity).The Baby SRM score ranged from 0 (least regular) to 7 (most regular).The researchers found that a higher SRM score was associated with lower overall levels of anxiety symptoms in childhood. There was no significant correlation of Baby SRM with childhood depression.Timothy Monk, Ph.D., a professor of psychiatry and director of the human chronobiology research program at the University of Pittsburgh, noted that an extensive body of research in adults has shown circadian rhythm is associated with mental health.“These new findings in infants reinforce this view,” he said. “In terms of treating patients both young and old, it is worth encouraging patients to adopt, to the extent that they can, a highly regular daily life style with predictable timing of bedtime, rise time, meals, and work.”Moreover, sociability and directed attention were both correlated with Baby SRM scores and with school-age anxiety and may serve as mediating factors.“Greater regularity to daily activities may increase the predictability of infant demands, leading to enhanced parental perception of need cues and increased parental confidence, which further strengthens caretaking routines,” the researchers stated. “Thus, greater regularity in daily activities may enhance early parent–infant relationships, improve infant regulatory capacity, and promote environmental exploration as internal resources are available.”This study was supported in part by funding from the National Institute of Mental Health, the National Institutes of Health, and the John D. and Catherine T. MacArthur Foundation.Child psychiatrist and APA Treasurer David Fassler, M.D., said the results of the study are consistent with previous reports and with general clinical experience. “We're well aware that young infants display a range of distinct temperaments,” he said. “We also know that many of these early characteristics persist throughout childhood and into adulthood. The present study demonstrates that anxiety in childhood correlates with specific behavior patterns observed during infancy.“The behavior of infants clearly affects and alters the nature of their interaction with their parents and other caregivers, which could easily influence emotional development from an early age,” Fassler said. “We also know that the expression of anxiety has a significant genetic component, elements of which could conceivably influence behavioral regularity during infancy.”“Behavioral Circadian Regularity at Age 1 Month Predicts Anxiety Levels During School-Age Years” is posted at <www.sciencedirect.com/science/journal/01651781>. ISSUES NewArchived

Behavioral circadian regularity at age 1 month predicts anxiety levels during school-age years

Daily lifestyle regularity is measured using the Social Rhythm Metric (SRM). We developed a Baby SRM, with 59 babies followed for ~13years. Baby SRM score at age 1 month significantly predicted the child's school (K-9, 5 time points) anxiety level (more regular=less anxious), and may be mediated through sociability and directed-attention pathways.

Enhancing Circadian Zeitgebers

THE LINK BETWEEN CIRCADIAN RHYTHMS AND SLEEP IS CLEARLY AN IMPORTANT ONE. THOSE OF US WHO STUDY THE EFFECTS OF AGING ON HUMAN circadian rhythms often seek to forge a link between the effects of aging on circadian rhythms (which most older persons and policy makers don't care about) and the effects of aging on sleep (which many older persons and policy makers do care about). Very often, the raison d'etre for the study of circadian rhythms in the aged (either explicitly stated or merely implied) is that such experiments might allow us to glean appropriate therapies for age-related circadian dysfunction. The hope is that by fixing older people's circadian rhythms we can fix their sleep, thus saving them from distress and, in some cases, inappropriately applied hypnotic medications. In this issue of SLEEP, Zisberg and colleagues1 present compelling evidence from a study of 89 Israeli seniors (both genders, mean age 75 y) to suggest that there are indeed certain circadian behaviors which may be associated with improved sleep. In particular, Zisberg, et al. used block multiple regression analyses to show that increased stability in daily routine (as measured by two separate instruments), predicted shorter sleep latency, higher sleep efficiency and increased overall sleep quality (using the Pittsburgh Sleep Quality Index).2 These effects were observed over and beyond those of functional status, comorbidities, and age. One instrument, the Scale of Older Adults' Routine (SOAR)3 involved three structured interviews spaced 2 weeks apart and yielded measures separately related to basic activities such as eating and sleeping, and to instrumental activities such as shopping and public transportation use. The other instrument, the Social Rhythm Metric (SRM)4 involved a prospective 2-week diary of the timing of five major daily events relating to sleep, meals and social contacts. Both instruments essentially yielded numbers representing the level of regularity of the individual's daily routine, and both were significantly correlated with self-rated sleep variables (and with each other). Circadian rhythms are driven by endogenous processes, are self-sustaining, and rely upon circadian time cues (zeitgebers) to remain appropriately oriented to the individual's environment and desired routine.5 The gold-standard measures of human circadian rhythms have been core body temperature and salivary or plasma melatonin levels. However, one can also make the case that the behavioral circadian rhythms related to the timing of sleep, meals, work and social interactions are just as valid circadian rhythms as the physiological ones. Moreover, these are the rhythms most salient to the individual himself or herself. The strength of behavioral circadian rhythms comprises the concept underlying the daily regularity scores, as measured by the SOAR and SRM in Zisberg et al.'s study(1). However, behavioral circadian rhythms are not only circadian rhythms in their own right, but also serve as gatekeepers to the zeitgebers that impinge on the individual and thus serve to entrain his/her circadian rhythms to a 24-h period. The most powerful of such zeitgebers are the photic ones resulting from sleeping in the dark, for example.5 There is, however, also evidence for non-photic zeitgebers such as exercise and social contacts.6 Thus the improved sleep observed by Zisberg et al.1 in seniors with a more regular daily lifestyle, may result both from the action of stronger behavioral circadian rhythms per se, and from those strong behavioral rhythms providing more coherent zeitgebers to the circadian system in general. Most behavioral treatments for insomnia7 include advice to the patient to be regular in their sleep timing (particularly in regard to rise-time), thus enhancing the strength of the patient's behavioral circadian rhythms. In both adults and college students, high SRM scores (greater daily regularity) have been shown to be associated with better subjective sleep.8,9 Perhaps more salient, though, is the issue of zeitgeber enhancement. A number of different studies10–12 have shown that enhancement of zeitgebers in elderly nursing home residents (e.g., by providing brighter light and/or daytime activities) can have beneficial effects on their sleep. Healthy seniors tend to have higher (i.e., more regular) lifestyles than do younger adults.13 In the auditory domain, those of us who work with the elderly often become accustomed to raising our voices slightly to accommodate their hearing loss. It may well be that seniors have found that a highly regular lifestyle has an equivalent effect in the circadian domain. By adopting a highly regular lifestyle it is possible that zeitgeber effects are amplified, perhaps accommodating age-related declines in endogenous circadian entrainment mechanisms. The Zisberg et al. findings1 raise the hope that simple behavioral therapies may, for some seniors, serve to improve their sleep. Future work needs to measure the physiological circadian rhythms and zeitgeber exposure of high- versus low-regularity seniors, in order to provide good theoretical underpinnings to such therapies.

Contribution of Routine to Sleep Quality in Community Elderly

Among the common problems related to aging is sleep quality; over half of older adults suffer from symptoms of insomnia. Age-related changes in circadian sleep/wake regulation constitute a major underlying factor. Constant and organized lifestyle may moderate the effects of circadian rhythm changes on sleep. Preliminary findings have linked daily regularity to sleep quality among healthy adults and in patients with Parkinson disease. The current study investigated the relationships between daily routines and sleep quality among community dwelling elderly. Ninety-six Israeli Russian-speaking elderly living in a retirement community (mean age 75 +/- 13.88, 72% women, 82% living alone) participated. Routines were assessed with the Scale of Older Adults Routine (SOAR) by a trained interviewer at 3 time points 2 weeks apart. A subsample (n = 33) completed the Social Rhythm Metric (SRM) 2-week diary. Sleep quality was evaluated using the Pittsburg Sleep Quality Index (PSQI). Daily Functional status was assessed with the Lawton Instrumental Activities of Daily Living (IADL). Mean sleep efficiency was 78%, functional status was fairly good (mean IADL 45 of 50 [SD = 6.12]). Regression analyses indicated that increased stability in daily routine, as measured by the SOAR for the entire sample, predicted shorter sleep latency, higher sleep efficiency and improved sleep quality, beyond functional status, comorbidities, and age. Similar associations were found for the subsample using the SRM. Maintenance of daily routines is associated with a reduced rate of insomnia in the elderly. Further studies should examine these relations in broader populations with regard to health, functional status, and cultural background.

Psychometric properties of Social Rhythm Metric in regular shift employees

To analyze the psychometric properties of Brazilian version of Social Rhythm Metric-17 and to present the score algorithm in regular shift employees. This is a cross-sectional study. The Social Rhythm Metric assess the regularity of daily life associated to changes in biological rhythms. The scale was applied, during nine days, to 145 employees, 27.6 % male and 72.4% female, ages between 18 and 60, mean = 36.1 (sd = 9.87). Mean values were compared using the Student's t-test for independent samples and ANOVA. Factor analysis was performed using principal component analysis; the reliability analysis, through Spearman's correlation. The Student t test didn't reveal any significant difference between sex in IRA (t = 0.60; p = 0.55) or ETA (t = 0.67; p = 0.95). The factor analysis showed three components, the first was associated to survival related activities; the second, related to pleasure and work and the third was related to no essential survive activities. This version of the Social Rhythm Metric-17 instrument allows to assess an important human zeitgeber, contributing for other studies which can to evaluate the determinant role of social rhythm. The Brazilian version of social rhythm metric 17 presents validity of content and good test-retest reliability.