Diurnal Rhythms in Co-Sleeping Couples: Does Being "In Sync" Matter?

Subjective feeling, or mood, is not just a product of situational and dispositional factors, but is also based in part on underlying circadian rhythms. Notably, accumulating evidence suggests that circadian patterning is limited to positive affect, possibly as an adaptive manifestation of an appetitive motivational system. Furthermore, dispositional factors may influence the observed patterning, such as blunting the rhythm in positive affect when depression is present. The present study sought to examine further these phenomenon at an individual-level, as well as to explore circadian and affective interactions at a couple-level for perhaps the first time by monitoring mood, interpersonal interactions, sleep, activity, and light in 31 bed-sharing cohabitating couples over the course of 7 days. Participants' depression, well-being, relationship satisfaction, and morningness-eveningness were also assessed. Systematic daily patterning was found in all three measures of affect, and was moderated by depression, well-being, and morningness-eveningness. Within-couple affective synchrony (covariation) was positively associated with relationship satisfaction, within-couple morningness-eveningness similarity, and synchrony of sleep timing. Finally, day-to-day within-couple sleep timing synchrony predicted the tenor of the following day's partner interactions and affect. These data provide further evidence of potentially important interactions between sleep, circadian, affective processes both within- and between-individuals

Chronotype and Mental Health: Recent Advances.

PURPOSE OF REVIEW: Evening chronotype is increasingly recognized as a correlate of, and perhaps a contributor to, mental illness. The current review evaluates recent evidence for the association between chronotype and mental illness and putative mechanisms underlying the association, while highlighting methodological advances and areas of research that are relatively under-examined in the literature. RECENT FINDINGS: While evening chronotype is most consistently associated with severity of mood disorder symptoms, emerging evidence implicates evening chronotype as a transdiagnostic correlate of substance use severity, anxiety symptoms, attentional difficulties, and maladaptive behaviors such as aggression. Longitudinal studies point to the possibility that evening chronotype precedes problematic substance use, depression, and anxiety. Neural processes related to reward and affective regulation may underlie associations between evening chronotype and illness. The literature on chronotype and mental illness has evolved to (1) include associations with a broader range of psychiatric symptom profiles; (2) explore underlying mechanisms; and (3) expand on earlier research using objective measures and more sophisticated study designs. In addition to further mechanistic research, additional work is needed to examine the stability and key subcomponents of the chronotype construct, as well as more attention to pediatric and special populations. This research is needed to clarify the chronotype-mental health relationship, and to identify how, when, and what aspects of chronotype can be targeted via therapeutic interventions

Affective synchrony in dual- and single-smoker couples: Further evidence of symptom-system fit ?

Couples in which one or both partners smoked despite one of them having a heart or lung problem discussed a health-related disagreement before and during a period of laboratory smoking. Immediately afterwards, the partners in these 25 couples used independent joysticks to recall their continuous emotional experience during the interaction while watching themselves on video. A couple-level index of affective synchrony, reflecting correlated moment-to-moment change in the two partners\u27 joystick ratings, tended to increase from baseline to smoking for 9 dual-smoker couples but decrease for 16 single-smoker couples. Results suggest that coregulation of shared emotional experience could be a factor in smoking persistence, particularly when both partners in a couple smoke. Relationship-focused interventions addressing this fit between symptom and system may help smokers achieve stable cessation. © 2009 FPI, Inc

Sleep and circadian differences between light and heavy adult alcohol drinkers

BackgroundNumerous studies have reported that eveningness is associated with increased alcohol consumption. However, biological markers of circadian timing, such as dim light melatonin onset (DLMO) and circadian photoreceptor responsivity (post‐illumination pupil response, PIPR), have rarely been assessed in the context of habitual alcohol consumption. This study aimed to examine sleep, circadian timing, and photoreceptor responsivity in adult alcohol drinkers.MethodsParticipants (21 to 45 years) included 28 light and 50 heavy drinkers. The 8‐day study consisted of a week of ad lib sleep monitored with wrist actigraphy, followed by a 9‐h laboratory session with a photoreceptor responsivity and circadian phase assessment.ResultsThe heavy drinkers obtained on average 28 more minutes of sleep (p = 0.002) and reported more eveningness than the light drinkers (p = 0.029). There was a trend for a shorter DLMO‐midsleep interval (p = 0.059) in the heavy drinkers, reflecting a tendency for them to sleep at an earlier circadian phase. The PIPR in the heavy drinkers was significantly smaller than in the light drinkers (p = 0.032), suggesting reduced circadian photoreceptor responsivity in the heavy drinkers. A larger PIPR was significantly associated with a later DLMO in the light drinkers (r = 0.44, p = 0.019), but this relationship was absent in the heavy drinkers (r = −0.01, p = 0.94).ConclusionsThese results are consistent with earlier reports of more eveningness and a shorter DLMO‐midsleep interval being associated with heavier alcohol drinking. The novel finding of reduced circadian photoreceptor responsivity in heavy drinkers is consistent with prior rodent studies. Future studies should explore the impact of habitual alcohol consumption on other measures of circadian photoreceptor responsivity.This study of light and heavy alcohol drinkers found that heavy alcohol drinking was associated with more eveningness, and a trend towards more circadian misalignment, as reflected in a shorter interval between the dim light melatonin onset and midpoint of sleep. Heavy drinking was also associated with reduced circadian responsivity to light, as assessed with the post‐illumination pupil response. The relationship between circadian responsivity to light and circadian timing was also weaker in heavy drinkers than in light drinkers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/174775/1/acer14872.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/174775/2/acer14872_am.pd

Evening chronotype, alcohol use disorder severity, and emotion regulation in college students.

The evening chronotype is strongly associated with greater alcohol use, though mechanisms underlying this association are not well understood. The current study evaluated emotion regulation as a potential mechanism linking evening chronotype and alcohol use. Participants were 81 undergraduate students. Chronotype was assessed using the Composite Scale of Morningness (CSM). Alcohol use disorder severity was assessed using the Alcohol Use Disorder Identification Test (AUDIT). Participants recorded daily sleep patterns using an online diary for seven days. Participants then completed a standardized laboratory emotion regulation task. Self-reported affect, high-frequency heart rate variability (HF-HRV), and pre-ejection period (PEP) were measured throughout the task. Sleep duration on non-free days (defined as days when sleep was restricted by morning obligations such as work or school) was evaluated as a moderator. Thirty-one evening chronotypes (CSM scores ≤ 26) were compared to 50 non-evening chronotypes (CSM scores \u3e26). Evening chronotypes reported significantly greater symptoms of alcohol use disorder