Romantic Love and Sleep Variations : Potential Proximate Mechanisms and Evolutionary Functions

This article provides a narrative review of what is known about romantic love and sleep variations and provides possible explanations for the association. Romantic love and sleep are described using a comprehensive, unifying framework advocated by Tinbergen. We summarise the findings of studies investigating the relationship between romantic love and sleep. Sleep variations are associated with romantic love in adolescents and young adults. We then detail some proximate mechanisms that may contribute to sleep variations in people experiencing romantic love before considering potential evolutionary functions of sleep variations in people experiencing romantic love. The relationship between symptoms of psychopathology and sleep variations in people experiencing romantic love is described. With the current state of knowledge, it is not possible to determine whether sleep variations associated with romantic love are adaptations or by-products of romantic love. We conclude by proposing areas for future research

Sleep and its timing : longitudinal and cross-sectional associations with cognitive performance and health in youth

Sleep has important functions for both health and cognitive performance. This thesis investigated typical, non-restricted sleep over a developmental span from middle childhood to early adulthood. Specifically, the focus was (1) identifying the cross-sectional associations between neurocognitive functioning and habitual sleep duration and sleep quality in early adolescence, and (2) studying the sleep behaviour associated with young adults’ executive functioning and self-control. Additionally, the goals included (3) studying the longitudinal associations between naturally occurring sleep and lipid profile in early adolescence, and, finally, (4) differentiating the developmental trajectories of sleep timing from middle childhood to adolescence from a circadian preference perspective. The participants came from two population-based cohorts, and all the studies in this thesis were done using actigraphs with piezoelectric accelerometers, which provide objective sleep measures based on movement. We found that during early adolescence, especially boys’ shorter sleep duration was associated with poorer performance in tests evaluating executive functioning. We found similar results in young adults, but also found that later sleep timing and regularity were associated with weaker trait-like executive functioning, such as self-control and behaviour regulation. Longitudinal analyses revealed that girls’ shorter sleep duration and irregular sleep in middle childhood were associated with a more detrimental lipid profile (higher levels of LDL cholesterol and triglycerides, lower levels of HDL cholesterol) in later life, during early adolescence. These associations survived controlling for body mass index and physical activity. We also analysed the sleep patterns of different circadian preference phenotypes longitudinally, and found that those adolescents with a preference for morningness differed from others in sleep timing already at age 8. This suggests long-term stability in sleep patterns. Based on these findings, objectively measured sleep and its timing have longitudinal pathways which connect to future health, and may act as risk factors or as protective features for various health related outcomes. It is also likely that sleep, self-control, and health behaviour are intertwined during development.Lasten ja nuorten riittämätön uni on yhä yleisempää. Liian vähäisen unen merkitystä lasten ja nuorten kehitykselle tunnetaan kuitenkin huonosti. Väitöskirjatutkimuksessa tarkasteltiin lasten ja nuorten nukkumistapojen yhteyksiä terveyteen ja kognitiiviseen suoriutumiseen 1998 Helsingissä syntyneiden lasten joukossa. Erityisenä kiinnostuksenkohteena olivat unen pidemmän aikavälin vaikutukset. Unen määrä ja ajoitus ovat melko pysyviä terveyskäyttäytymisen piirteitä myös lapsilla ja nuorilla. Tulokset osoittivat, että lyhyt unen kesto 8-vuotiaana on yhteydessä 12-vuotiaana mitattuun, haitalliseksi arvioituun lipidiprofiiliin – varsinkin tyttöjen keskuudessa. Epäsuotuisaan tai haitalliseen lipidiprofiiliin liittyvät korkeat LDL-kolesteroli- ja triglyseridiarvot, sekä alhaisemmat HDL-kolesteroliarvot. Yhteys oli voimakkaampi 4-vuoden seurantajakson yli kuin poikittaistutkimuksessa 8-vuotiaana. Tämä voi tarkoittaa sitä, että lyhyen unen aiheuttama haitallinen vaikutus terveyteen syntyy pikkuhiljaa, useamman vuoden aikana. Tutkimuksessa myös havaittiin, että lyhyt unen kesto vaikutti veriarvoihin riippumatta yksilön painoindeksistä tai kertyneen liikunnan määrästä. Toisin sanoen edes liikunta ei suojannut riittämättömän unen negatiiviselta vaikutukselta. Tulosta voi tarkastella myös terveyden edistämisen kannalta: pidempi ja säännöllisempi uni suojaa haitallisen lipidiprofiilin kehittymiseltä. Tutkimuksessa havaittiin myös, että unen ajoitus eriytyy aamu- ja ilta-kronotyyppien välillä jo lapsuudessa. Aamutyyppien aikaisempi unirytmi havaittiin jo kahdeksanvuotiailla. Vaikka kaikkien lasten unirytmi muuttui myöhäisemmäksi nuoruudessa, iltatyyppien unirytmi muuttui merkittävästi myöhemmäksi 12 ikävuoden jälkeen. Havainnot vahvistavat käsitystä siitä, että varhainen unirytmi voi säilyä suojaavana tekijänä myöhempään nuoruuteen saakka. Väitöskirjan kognitiivista suoriutumista koskevissa tutkimuksissa osoitettiin, että unen määrä ja ajoitus ovat vahvasti yhteydessä toiminnanohjaukseen, eli siihen, miten hallitsee ja ohjaa omaa elämäänsä. Onkin todennäköistä, että uni, toiminnanohjaus, ja terveyskäyttäytyminen ovat vastavuoroisesti yhteydessä toisiinsa

Nuori nukkuu myrskyn silmässä

VertaisarvioituNuoruus on dramaattinen ajanjakso aivojen kehityksessä. Tämä näkyy myös unessa. Unen ajoitus siirtyy, ja kyky vastustaa unipainetta paranee. Nuori etsii autonomiaa nukkumiseen liittyvissä asioissa. Riittämätön uni heikentää kognitiivisia toimintoja ja aiheuttaa monia riskejä. Unen lyhentyminen ja muutokset aivoissa liittyvät toisiinsa, mutta syy-seuraussuhdetta niiden välille ei ole syytä olettaa.Peer reviewe

Does counter-habitual behavior carry psychological costs?

Experience sampling studies have shown that people act out of character a lot of the time. These findings have raised the question of potential costs of counter-habitual behavior. The present experience sampling study (N = 242; measurement occasions = 4342) tested, for five behavioral dimensions derived from the Big Five theory, whether self-reported counter-habitual behavior is related to psychological costs in everyday life. The results mostly supported the view that engaging in desirable counter-habitual behaviors is beneficial, though some evidence for counter-habitual costs was found for self-control. Overall, the results suggest that the state-content significance hypothesis better accounts for everyday life behavioral, affective, and self-regulatory processes than the views highlighting the importance of acting according to one's "true self" (C) 2021 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Peer reviewe

Emotions relating to romantic love-further disruptors of adolescent sleep

Objective: Early-stage romantic involvement may resemble hypomania in its manifestation on behavioral, physiological, and psychological levels. Previous research suggests that self-reported sleep duration may diminish as a result of falling in love during adolescence. We investigated how feelings of infatuation are related to subjective and objective measures of sleep duration, quality, and timing. Methods: 1374 adolescents (66% girls; mean age: 16.9, SD=0.6 years) selected from the population register responded to online questionnaires regarding romantic love, mental well-being, and sleep behavior. A sub-sample (n=309) underwent a week-long actigraphy measurement (GENEActiv Original). We compared the sleep duration, quality, and timing of those who reported being in the early stages of love to those who were not. Results: 11% of all participants reported being in the early stages of romantic love. Those girls and boys who were in love had higher scores of depression and anxiety than others. Girls who were in love reported poorer sleep quality, later sleep timing, and shorter sleep duration both on weekdays (mean difference: 32 minutes, p Conclusions: We conclude that romantic love is one further cause for short or poor quality sleep in girls and may relate to symptoms of depression and anxiety in both sexes. However, feelings of infatuation contain important developmental lessons. (C) 2020 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.Peer reviewe

Autistic traits and sleep in typically developing adolescents

Objective: Diagnosed autism spectrum disorders have been associated with a high prevalence of sleep problems, other psychiatric disorders and social deficits in adolescence. However, little is known about the possible connection between subclinical autistic traits and sleep. This study explored whether adolescents with elevated levels of subclinical autistic traits are at heightened risk for sleep problems. Methods: This study used data from the community cohort born in 1998. The sample consisted of 157 (57% girls) 17-year-old adolescents. Autistic traits were assessed using the Autism Spectrum Quotient (AQ). The Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), and the Adult ADHD Self-Report Scale were utilized to control for comorbid psychiatric symptoms. Sleep was measured with actigraphy and sleep quality was self-rated using the Pittsburgh Sleep Quality Index (PSQI). Associations between autistic traits and sleep were examined using logistic regression analysis. Results: Elevated levels of autistic traits were significantly associated with shorter weekday sleep duration. Moreover, autistic traits remained an independent predictor of short sleep duration when comorbid psychiatric symptoms were controlled for (OR 1.14; 95% CI: 1.03-1.26). Conclusions: The results suggest that subclinical autistic traits should be considered as a possible underlying mechanism affecting adolescent sleep. (c) 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Adolescent circadian patterns link with psychiatric problems : A multimodal approach

Circadian rhythms orchestrate brain function and mental wellbeing. We compared circadian patterns derived from continuous measurements of body temperature, sleep actigraphy and self-reported circadian preference in relation to different psychiatric disorders. 342 adolescents (70% females) aged 17.4y underwent M.I.N.I. psychiatric interviews, wore Ibutton 1922L skin temperature loggers (n = 281; 3 days), completed one-week GeneActiv Original actigraphy measurements (n = 306) and responded to Morningness-Eveningness Questionnaire (MEQ; n = 330). We derived circadian period length and amplitude from the temperature loggers. Actigraphy measures included sleep duration, midpoint, efficiency, and irregularity as well as Delayed Sleep Phase (DSP) characteristics (bedtime after 1 a.m. 3 times/week). M.I.N.I. psychiatric interviews suggested that 36% of participants had one or more psychiatric problem, with 21% suffering from comorbidity. Severe depression was associated with longer circadian period (p = 0.002). Suicidality was associated with later midpoint (p = 0.007) and more irregular sleep (p = 0.007). Those with agoraphobia slept longer (p = 0.013). Manic episodes and psychotic disorders were associated with irregular sleep (p-values < 0.02). DSP was related to suicidality (p = 0.026), panic disorder (p = 0.022), and greater comorbidity (p = 0.026). Preference for eveningness was similarly related to higher prevalence of Generalized Anxiety Disorder (p = 0.014), social anxiety (p = 0.03), agoraphobia (p = 0.026), panic disorder (p = 0.004), suicidality (p = 0.018), severe depression (p < 0.001), and comorbidity (p < 0.001). Deviations in circadian rhythms were widely associated with psychiatric problems, whereas sleep duration was not. Especially suicidality linked with several markers of circadian disruption: later sleep midpoint, irregular sleep, and DSP characteristics. Longer circadian period length was associated with severe depression.Peer reviewe

Assessment of time window for sleep onset on the basis of continuous wrist temperature measurement

The interactions of the principal circadian clock with the homeostatic sleep process create the time-sensitive window for easy falling asleep in the evening, which is affected by a thermoregulatory process. It has been hypothesized that the changes in skin and core body temperatures before the sleep onset might play a direct role in sleep regulation. To determine this time window, we recorded from 20 healthy participants (11 women and 9 men), aged 26-58 years, one overnight own-home ambulatory polysomnography and measured continuously wrist skin temperature with a wrist-worn accelerometer containing a skin temperature thermometer. Wrist skin temperatures which were read out from the thermometer of the accelerometers were modeled using linear mixed models, and the linear effect of time before the sleep onset on wrist temperature was analyzed using a mixed model with the sex and age as the covariates. We found that wrist skin temperatures increased on average by 0.6 degrees (of Celcius) in 10 min prior to the sleep onset and could be tracked robustly along a slope of time (p = 0.004). Our current findings may be useful in further characterizing the window of time and its boundaries for easy falling asleep.Peer reviewe

Dynamic fluctuations of emotional states in adolescents with delayed sleep phase-A longitudinal network modeling approach

Background: Very late sleep rhythms are risks for social adjustment problems in adolescence. Using ecological momentary assessment data, we quantified and visualized temporal and contemporaneous within-persons dynamical relations of sleepiness and emotions in adolescents with and without late sleep rhythms. Methods: We analyzed a temporal network via multilevel vector autoregression (mlVAR) modeling and a contemporaneous network through the partial associations between the residuals of temporal and the between-subject multilevel models. We tested whether these networks were different between those with a late circadian rhythm [concurrent delayed sleep phase (DSP) N = 172, 37% boys, 63% girls] and those without (N = 143, 22% boys, 78% girls). Results: In adolescents without DSP, the temporal networks showed continuity only for low mood from the previous to the following time point. In adolescents with DSP, there were more predictable patterns of emotions. Feelings of depression led to a decrease of positive emotions and increase of irritation and anxiety. The contemporaneous networks showed clusters of positive and negative emotions in both groups and sleepiness decreased the experience of positive emotions concurrently. Limitations: DSP in our current study was based only on one out of three diagnostic criteria of the full disorder (DSM-5) and it was assessed only once. Conclusions: These findings indicate that the dynamic organization of emotions and sleepiness is different in adolescents with and without DSP. DSP adolescents have more predictable and maladaptive emotional patterns during the day. Results provide new insight about why individuals with DSP are at a heightened risk for decreased emotional adjustment.Peer reviewe

The association between sleep-wake ratio and overnight picture recognition is moderated by BDNF genotype

A wealth of studies supports the role of sleep in memory performance. Experimentally controlled studies indicate that prolonged wake after memory encoding is detrimental for memory outcome whereas sleep protects from wake-time interference and promotes memory consolidation. We examined how the natural distribution of wake and sleep between encoding and retrieval associated with overnight picture recognition accuracy among 161 adolescents following their typical sleep schedule with an in-home polysomnography. The memorized pictures varied in their level of arousal (calm to exciting) and valence (negative to positive). Suspecting genotypic influence on the sensitivity for sleep/wake dynamics, we also assessed if these associations were affected by known gene polymorphisms involved in neural plasticity and sleep homeostasis: brain-derived neurotrophic factor (BDNF) Val66Met and Catechol‐O‐methyltransferase (COMT) Val158Met. In the whole sample, overnight recognition accuracy was associated with the levels of arousal and valence of the pictures, but not with sleep percentage (i.e. the percentage of time spent asleep between memory encoding and retrieval). While the allelic status of BDNF or COMT did not have any main effect on recognition accuracy, a significant moderation by BDNF Val66Met was found (p = .004): the subgroup homozygous for valine allele showed positive association between sleep percentage and recognition accuracy. This was underlain by detrimental influence of wake, rather than by any memory benefit of sleep. Our results complement the mounting evidence that the relation between sleep and memory performance is moderated by BDNF Val66Met. Further studies are needed to clarify the specific mechanisms.Peer reviewe