Circadian rhythms, sleep, and substance abuse

Exploring the association between melatonin and nicotine dependence (Review)

Due to the addictive qualities of tobacco products and the compulsive craving and dependence associated with their use, nicotine dependence continues to be a serious public health concern on a global scale. Despite awareness of the associated health risks, nicotine addiction contributes to numerous acute and chronic medical conditions, including cardiovascular disease, respiratory disorders and cancer. The nocturnal secretion of pineal melatonin, known as the 'hormone of darkness', influences circadian rhythms and is implicated in addiction‑related behaviors. Melatonin receptors are found throughout the brain, influencing dopaminergic neurotransmission and potentially attenuating nicotine‑seeking behavior. Additionally, the antioxidant properties of melatonin may mitigate oxidative stress from chronic nicotine exposure, reducing cellular damage and lowering the risk of nicotine‑related health issues. In addition to its effects on circadian rhythmicity, melatonin acting via specific neural receptors influences sleep and mood, and provides neuroprotection. Disruptions in melatonin signaling may contribute to sleep disturbances and mood disorders, highlighting the potential therapeutic role of melatonin in addiction and psychiatric conditions. Melatonin may influence neurotransmitter systems involved in addiction, such as the dopaminergic, glutamatergic, serotonergic and endogenous opioid systems. Preclinical studies suggest the potential of melatonin in modulating reward processing, attenuating drug‑induced hyperactivity and reducing opioid withdrawal symptoms. Chronotherapeutic approaches targeting circadian rhythms and melatonin signaling show promise in smoking cessation interventions. Melatonin supplementation during periods of heightened nicotine cravings may alleviate withdrawal symptoms and reduce the reinforcing effects of nicotine. Further research is required however, to examine the molecular mechanisms underlying the melatonin‑nicotine association and the optimization of therapeutic interventions. Challenges include variability in individual responses to melatonin, optimal dosing regimens and identifying biomarkers of treatment response. Understanding these complexities could lead to personalized treatment strategies and improve smoking cessation outcomes.

Augmentation of intracranial self-stimulation induced by amphetamine-like drugs in Period circadian regulator 2 knockout mice is associated with intracellular Ca2+ levels

Over the past decade, new psychoactive substances (NPS) have emerged in the illegal drug market and have continued to attract attention from the international community. Among these, amphetamine-like NPS, classified as stimulants, constitute a significant proportion. However, the pharmacological characteristics and mechanisms underlying addiction to amphetamine-like NPS remain poorly understood. Given that circadian rhythms are linked to the brain stimulation effects of methamphetamine (METH) and amphetamine, we investigated the effects of METH, 1-(4-methoxyphenyl)-N-methylpropan-2-amine (PMMA), and 1-(benzofuran-5-yl)-N-ethylpropan-2-amine (5-EAPB) on intracranial self-stimulation (ICSS) in wild-type (WT) or Period circadian regulator 2 knockout mice. Amphetamine-like drugs increase intracellular Ca2+ levels to provoke dopamine release, so we examined the impact of Per2 knockdown on intracellular Ca2+ levels in PC12 cells to elucidate a potential mechanism underlying NPS-induced ICSS enhancement. Our ICSS results showed that METH and PMMA significantly increased brain stimulation in Per2 knockout mice compared to WT mice. Similarly, METH and PMMA induced higher Ca2+ fluorescence intensity in Per2 knockdown PC12 cells than in control cells. In contrast, 5-EAPB did not produce significant changes in either ICSS or Ca2+ signaling. These findings suggest that Per2 plays a crucial role in the brain stimulation effects of amphetamine-like drugs through the regulation of intracellular Ca2+.

Coordination among frequent genetic variants imparts substance use susceptibility and pathogenesis

Determining the key genetic variants is a crucial step to comprehensively understand substance use disorders (SUDs). In this study, utilizing whole exome sequences of five multi-generational pedigrees with SUDs, we used an integrative omics-based approach to uncover candidate genetic variants that impart susceptibility to SUDs and influence addition traits. We identified several SNPs and rare, protein-function altering variants in genes, GRIA3, NCOR1, and SHANK1; compound heterozygous variants in LNPEP, LRP1, and TBX2, that play a significant role in the neurotransmitter-neuropeptide axis, specifically in the dopaminergic circuits. We also noted a greater frequency of heterozygous and recessive variants in genes involved in the structural and functional integrity of synapse receptors, CHRNA4, CNR2, GABBR1, DRD4, NPAS4, ADH1B, ADH1C, OPRM1, and GABBR2. Variant analysis in upstream promoter regions revealed regulatory variants in NEK9, PRRX1, PRPF4B, CELA2A, RABGEF1, and CRBN, crucial for dopamine regulation. Using family-and pedigree-based data, we identified heterozygous recessive alleles in LNPEP, LRP1 (4 frameshift deletions), and TBX2 (2 frameshift deletions) linked to SUDs. GWAS overlap identified several SNPs associated with SUD susceptibility, including rs324420 and rs1229984. Furthermore, miRNA variant analysis revealed notable variants in mir-548 U and mir-532. Pathway studies identified the presence of extensive coordination among these genetic variants to impart substance use susceptibility and pathogenesis. This study identified variants that were found to be overrepresented among genes of dopaminergic circuits participating in the neurotransmitter-neuropeptide axis, suggesting pleiotropic influences in the development and sustenance of chronic substance use. The presence of a diverse set of haploinsufficient variants in varying frequencies demonstrates the existence of extraordinary coordination among them in attributing risk and modulating severity to SUDs.

Reductions in World Health Organization risk drinking level are associated with improvements in sleep problems among individuals with alcohol use disorder

AIMS

Among individuals with alcohol use disorder (AUD), sleep disturbances are pervasive and contribute to the etiology and maintenance of AUD. However, despite increased attention toward the relationship between alcohol use and sleep, limited empirical research has systematically examined whether reductions in drinking during treatment for AUD are associated with improvements in sleep problems.

METHODS

We used data from a multisite, randomized, controlled trial that compared 6 months of treatment with gabapentin enacarbil extended-release with placebo for adults with moderate-to-severe AUD (N = 346). The Timeline Follow-back was used to assess WHO risk drinking level reductions and the Pittsburgh Sleep Quality Index was used to assess sleep quality over the prior month at baseline and the end of treatment.

RESULTS

Sleep problem scores in the active medication and placebo groups improved equally. Fewer sleep problems were noted among individuals who achieved at least a 1-level reduction (B = -0.99, 95% confidence interval (CI) [-1.77, -0.20], P = .014) or at least a 2-level reduction (B = -0.80, 95% CI [-1.47, -0.14], P = .018) in WHO risk drinking levels at the end of treatment. Reductions in drinking, with abstainers excluded from the analysis, also predicted fewer sleep problems at the end of treatment (1-level: B = -1.01, 95% CI [-1.83, -0.20], P = .015; 2-level: B = -0.90, 95% CI [-1.59, -0.22], P = .010).

CONCLUSIONS

Drinking reductions, including those short of abstinence, are associated with improvements in sleep problems during treatment for AUD. Additional assessment of the causal relationships between harm-reduction approaches to AUD and improvements in sleep is warranted.

Sleep-Related Predictors of Risk for Alcohol Use and Related Problems in Adolescents and Young Adults

PURPOSE

Growing evidence supports sleep and circadian rhythms as influencing alcohol use and the course of alcohol use disorder (AUD). Studying sleep/circadian-alcohol associations during adolescence and young adulthood may be valuable for identifying sleep/circadian-related approaches to preventing and/or treating AUD. This paper reviews current evidence for prospective associations between sleep/circadian factors and alcohol involvement during adolescence and young adulthood with an emphasis on the effects of sleep/circadian factors on alcohol use.

SEARCH METHODS

The authors conducted a literature search in PsycInfo, PubMed, and Web of Science using the search terms "sleep" and "alcohol" paired with "adolescent" or "adolescence" or "young adult" or "emerging adult," focusing on the title/abstract fields, and restricting to English-language articles. Next, the search was narrowed to articles with a prospective/longitudinal or experimental design, a sleep-related measure as a predictor, an alcohol-related measure as an outcome, and confirming a primarily adolescent and/or young adult sample. This step was completed by a joint review of candidate article abstracts by two of the authors.

SEARCH RESULTS

The initial search resulted in 720 articles. After review of the abstracts, the list was narrowed to 27 articles reporting on observational longitudinal studies and three articles reporting on intervention trials. Noted for potential inclusion were 35 additional articles that reported on studies with alcohol-related predictors and sleep-related outcomes, and/or reported on candidate moderators or mediators of sleep-alcohol associations. Additional articles were identified via review of relevant article reference lists and prior exposure based on the authors' previous work in this area.

DISCUSSION AND CONCLUSIONS

Overall, the review supports a range of sleep/circadian characteristics during adolescence and young adulthood predicting the development of alcohol use and/or alcohol-related problems. Although sleep treatment studies in adolescents and young adults engaging in regular and/or heavy drinking show that sleep can be improved in those individuals, as well as potentially reducing alcohol craving and alcohol-related consequences, no studies in any age group have yet demonstrated that improving sleep reduces drinking behavior. Notable limitations include relatively few longitudinal studies and only two experimental studies, insufficient consideration of different assessment timescales (e.g., day-to-day vs. years), insufficient consideration of the multidimensional nature of sleep, a paucity of objective measures of sleep and circadian rhythms, and insufficient consideration of how demographic variables may influence sleep/circadian-alcohol associations. Examining such moderators, particularly those related to minoritized identities, as well as further investigation of putative mechanistic pathways linking sleep/circadian characteristics to alcohol outcomes, are important next steps.

Efficacy of non-pharmacological interventions for sleep quality in Parkinson's disease: a systematic review and network meta-analysis

Background

Sleep disorders are one of the most common non-motor symptoms in PD. It can cause a notable decrease in quality of life and functioning in PD patients, as well as place a huge burden on both patients and caregivers. Currently, there are numerous non-pharmacological interventions available to improve sleep quality in PD, with disagreement as to which intervention is most effective. This network meta-analysis was performed to compare and rank non-pharmacological interventions to explore their efficacy in improving sleep quality in PD and to select the best interventions, with a view to providing references and bases for the development of clinical treatments and care programs.

Methods

The PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang databases were searched from inception to December 6, 2023. Two authors independently screened all studies, extracted the data, and evaluated risk of bias of included studies. STATA software version 17.0 was used to conduct the network meta-analysis.

Results

Our network meta-analysis included 29 studies involving 1,477 participants and 16 non-pharmacological interventions. Although most nonpharmacological interventions showed non-significant effects, the surface under the cumulative ranking curve (SUCRA) values indicated that the best non-pharmacological intervention for sleep disorders was massage therapy (97.3%), followed by music therapy (94.2%), and Treadmill training (85.7%).

Conclusion

Massage therapy can be considered as an effective therapy for improving sleep quality in patients with PD. Due to limited quantity and quality of the included studies, more high quality studies are required to verify the conclusions of this network meta-analysis.

Systematic review registration

identifier CRD42023429339, PROSPERO (york.ac.uk).

Time is of the essence: The importance of considering biological rhythms in an increasingly polluted world

Biological rhythms have a crucial role in shaping the biology and ecology of organisms. Light pollution is known to disrupt these rhythms, and evidence is emerging that chemical pollutants can cause similar disruption. Conversely, biological rhythms can influence the effects and toxicity of chemicals. Thus, by drawing insights from the extensive study of biological rhythms in biomedical and light pollution research, we can greatly improve our understanding of chemical pollution. This Essay advocates for the integration of biological rhythmicity into chemical pollution research to gain a more comprehensive understanding of how chemical pollutants affect wildlife and ecosystems. Despite historical barriers, recent experimental and technological advancements now facilitate the integration of biological rhythms into ecotoxicology, offering unprecedented, high-resolution data across spatiotemporal scales. Recognizing the importance of biological rhythms will be essential for understanding, predicting, and mitigating the complex ecological repercussions of chemical pollution.

p75NTR promotes tooth rhythmic mineralization via upregulation of BMAL1/CLOCK

The circadian clock plays a critical role in dentomaxillofacial development. Tooth biomineralization is characterized by the circadian clock; however, the mechanisms underlying the coordination of circadian rhythms with tooth development and biomineralization remain unclear. The p75 neurotrophin receptor (p75NTR) is a clock factor that regulates the oscillatory components of the circadian rhythm. This study aims to investigate the impact of p75NTR on the rhythmic mineralization of teeth and elucidate its underlying molecular mechanisms. We generated p75NTR knockout mice to examine the effects of p75NTR deficiency on tooth mineralization. Ectomesenchymal stem cells (EMSCs), derived from mouse tooth germs, were used for in vitro experiments. Results showed a reduction in tooth mineral density and daily mineralization rate in p75NTR knockout mice. Deletion of p75NTR decreased the expression of DMP1, DSPP, RUNX2, and ALP in tooth germ. Odontogenic differentiation and mineralization of EMSCs were activated by p75NTR. Histological results demonstrated predominant detection of p75NTR protein in odontoblasts and stratum intermedium cells during rapid formation phases of dental hard tissue. The mRNA expression of p75NTR exhibited circadian variations in tooth germs and EMSCs, consistent with the expression patterns of the core clock genes Bmal1 and Clock. The upregulation of BMAL1/CLOCK expression by p75NTR positively regulated the mineralization ability of EMSCs, whereas BMAL1 and CLOCK exerted a negative feedback regulation on p75NTR by inhibiting its promoter activity. Our findings suggest that p75NTR is necessary to maintain normal tooth biomineralization. Odontogenic differentiation and mineralization of EMSCs is regulated by the p75NTR-BMAL1/CLOCK signaling axis. These findings offer valuable insights into the associations between circadian rhythms, tooth development, and biomineralization.

Sex Differences in the Relationship between Chronotype and Eating Behaviour: A Focus on Binge Eating and Food Addiction

BACKGROUND

Men are more likely than women to have subthreshold overeating disorders. Lifestyle plays a role as a determinant, while chronotype is an emerging factor. Chronotype explains the natural preferences of wakefulness and activity throughout the day: evening chronotypes (E-Types), those most productive in the evening, have been linked with unhealthy dietary patterns and a higher propensity to substance addiction than morning types (M-Types).

METHODS

We carried out a cross-sectional study on 750 overweight or obese adults (70% females, 48 ± 10 years, BMI 31.7 ± 5.8 kg/m2). The Binge-Eating Scale, the Yale Food Addiction Scale 2.0 (YFAS 2.0), the reduced Morningness-Eveningness Questionnaire (rMEQ), and the MEDAS questionnaire were used to assess binge eating, food addiction, chronotype, and adherence to the Mediterranean diet, respectively.

RESULTS

No differences in BES binge-eating and FA food-addiction scores occurred between chronotypes, but we found significant interactions between sex × rMEQ score. While women showed the same prevalence for binge eating and food addiction across all chronotypes, binge eating and food addiction risk increased with reducing rMEQ score in men, indicating that being male and E-Type increases the risk association of binge eating and/or food addiction prevalence.

CONCLUSIONS

chronotype is associated with binge eating and food addiction in men, emphasizing the link between chronobiology and sex differences as determinants in appetite and eating behaviour dysregulation and in overweight and obesity.

Sensation seeking, drinking motives, and going out mediate the link between eveningness and alcohol use and problems in adolescence

The present study was aimed at obtaining a more comprehensive understanding of the possible mediating factors in the morningness-eveningness → alcohol consumption relation. We explored the role of mediators such as sensation seeking, the frequency of going out in the evenings, and drinking motives. We tested the proposed mediation model via structural equation modeling based on cross-sectional research conducted among Hungarian adolescents and young adults (N = 1695, 42.5% male, Mage = 18.98, SDage = 1.89). The outcomes included the frequency of alcohol consumption and problematic drinking. Both alcohol consumption and problematic drinking were predicted in similar directions and magnitudes by sensation seeking, "going out," and coping drinking motives. However, eveningness still had a significant direct effect on alcohol consumption and problematic drinking after we controlled for sensation seeking, going out, and drinking motives. For problematic drinking, the possible role of drinking motives seems to be higher and more complex than it is for alcohol consumption. The mediators, such as sensation seeking, the amount of time spent out in the evenings, and drinking motives, can explain the eveningness → alcohol consumption relationship and should be targeted for alcohol prevention programs among evening-type adolescents.

Circadian disruption and psychostimulants dysregulates plasma acute-phase proteins and circulating cell-free mitochondrial DNA

Background

Previous studies have indicated a close link between the inflammatory response, exacerbated by circadian disruption and psychostimulants such as cocaine and methamphetamine (METH). Indicators of this inflammation include cortisol and acute-phase proteins (APPs) like C-reactive protein (CRP), complement C3 (C3), and serum amyloid A (SAA). The connection between these inflammation markers and circulating mitochondrial DNA (mtDNA) has been gaining attention. However, the specific influence of cocaine and METH on APP, cortisol, and mtDNA levels in mice with disturbed circadian rhythm has yet to be explored, which is the main aim of this research.

Methods

In our study, we employed 10-12-week-old male C57BL/6J mice, which underwent an imposed 6-h phase advance every six days for a total of eight cycles. This process led to the formation of mice with disrupted circadian rhythm and sleep disorders (CRSD). We administered 11 dosages of cocaine and METH 15 mg/kg and 20 mg/kg, respectively to these CRSD mice over the course of 22 days. Quantitative assessments of CRP, C3, SAA, cortisol, and cell-free circulating mtDNA were conducted using enzyme-linked immunosorbent assay (ELISA), Western Blot, and quantitative real-time polymerase chain reaction (qRT-PCR) techniques.

Results

The experiment revealed that disruption in circadian rhythm alone or cocaine or METH on their own increased CRP, C3, SAA, and cortisol levels in comparison with the control group. CRSD mice, exposed to cocaine and METH, showed a significant rise in CRP, C3, and SAA, while those without exposure remained stable. We also found a reduction in circulating cell-free mtDNA in all CRSD mice, regardless of cocaine and METH exposure.

Conclusions

The findings of our study affirm that the levels of CRP, C3, SAA, and cortisol, which reflect inflammation, are enhanced by circadian disruption, cocaine, and METH, and these levels show a strong correlation with the content of circulating cell-free mtDNA. Furthermore, it also shows the potential link between the disruption of the circadian clock and the inflammatory response triggered by cocaine and METH.

Updates and confounding factors in delayed sleep-wake phase disorder

Delayed sleep-wake phase disorder (DSWPD) is a circadian rhythm sleep disorder characterised by a delay in the main sleep period, with patients experiencing difficulty getting to sleep and waking up at socially appropriate times. This often causes insomnia and compromised sleep, results in impairment to daytime function and is associated with a range of comorbidities. Besides interventions aimed at ameliorating symptoms, there is good evidence supporting successful phase advancement with bright light therapy or melatonin administration. However, no treatment to date addresses the tendency to phase delay, which is a common factor amongst the various contributing causes of DSWPD. Circadian phase markers such as core body temperature and circulating melatonin typically correlate well with sleep timing in healthy patients, but numerous variations exist in DSWPD patients that can make these unpredictable for use in diagnostics. There is also increasing evidence that, on top of problems with the circadian cycle, sleep homeostatic processes actually differ in DSWPD patients compared to controls. This naturally has ramifications for management but also for the current approach to the pathogenesis itself in which DSWPD is considered a purely circadian disorder. This review collates what is known on the causes and treatments of DSWPD, addresses the pitfalls in diagnosis and discusses the implications of current data on modified sleep homeostasis, making clinical recommendations and directing future research.

Health Outcomes by Neighborhood (HON): Effects of Neighborhood, Social Instability, and Health Factors on 12-Month Trajectories of Substance-Use Disorder Symptoms

BACKGROUND

Previous studies have shown that environment and health can influence drug use trajectories and the effects of substance use disorder (SUD) treatments. We hypothesized that trajectories of drug use-related problems, based on changes in DSM-5 symptoms, would vary by type(s) of drugs used, health factors, and neighborhood characteristics.

METHODS

We assessed mental and physical health, stress, social instability, neighborhood characteristics (disorderliness and home value), and DSM-5 symptom counts at two study visits, 12 months apart, in a community sample (baseline N = 735) in Baltimore, MD. Three prominent categories of drug-use trajectory were identified with K-means cluster analysis of symptom counts: Persistent (4 or more symptoms at both visits or at Visit 2), Improved (decrease from 4 or more symptoms at Visit 1 to 3 or fewer symptoms at Visit 2), and Low-Stable (3 or fewer symptoms at both visits). Baseline health and neighborhood measures were tested as predictors of trajectory in mediation and moderation models.

RESULTS

Among people with current opioid- and/or stimulant-use, odds of an Improved trajectory were (1) decreased with neighborhood disorder and social instability, or (2) increased with home value and social instability. Odds of a Low-Stable trajectory were decreased by social instability and stress but increased in those who were older or self-identified as white.

CONCLUSIONS

Trajectories of drug use-related problems are influenced by sociodemographic variables, neighborhood factors, and health. Assessing DSM-5 symptom counts as an outcome measure may be valuable in monitoring or predicting long-term trajectories and treatment effectiveness.

Use of a Fitbit-like device in rats: Sex differences, relation to EEG sleep, and use to measure the long-term effects of adolescent ethanol exposure

BACKGROUND

Sleep difficulties and rhythm disturbances are some of the problems associated with adolescent binge drinking. Recently, animal models of alcohol-induced insomnia have been developed. However, studies in human subjects have recently focused not only on nighttime EEG findings but also on daytime sleepiness and disrupted activity levels as typically measured by activity tracking devices such as the "Fitbit." We sought to develop and test a Fitbit-like device (the "FitBite") in rats and use it to track rest-activity cycles following adolescent alcohol exposure.

METHODS

The effects of 5 weeks of adolescent ethanol vapor or control conditions were evaluated in 48 male and female Wistar rats using FitBite activity while intoxicated, and during acute (24 h post-vapor exposure) and chronic withdrawal (4 weeks post-vapor exposure). Data were analyzed using activity count and cosinor analyses. Fourteen rats were subsequently implanted with cortical electrodes, and data from the FitBite were compared with EEG data to determine how well the FitBite could identify sleep and activity cycles.

RESULTS

Female rats were generally more active than males, with higher circadian rhythm amplitudes and mesors (rhythm-adjusted means) across a 24-h period. There were significant correlations between EEG-estimated sleep and activity counts using the FitBite. When the rats were tested during intoxication after 4 weeks of ethanol vapor exposure, they had significantly less overall activity. Disruptions in circadian rhythm were also found with significant decreases in the circadian amplitude, mesor, and a later shift in the acrophase. At 24 h of ethanol withdrawal, rats had more episodes of activity with shorter durations during the daytime, when rats are expected to spend more of their time sleeping. This effect remained at 4 weeks following withdrawal, but circadian rhythm disruptions were no longer present.

CONCLUSIONS

A Fitbit-like device can be successfully used in rats to assess rest-activity cycles. Adolescent alcohol exposure produced circadian rhythm disturbances that were not observed after withdrawal. Fragmentation of ultradian rest-activity cycles during the light period was found at 24 h and 4 weeks after withdrawal and support data demonstrating the presence of sleep disturbance long after alcohol withdrawal.

Does circadian dysrhythmia drive the switch into high- or low-activation states in bipolar I disorder?

OBJECTIVES

Emerging evidence suggests a role of circadian dysrhythmia in the switch between "activation" states (i.e., objective motor activity and subjective energy) in bipolar I disorder.

METHODS

We examined the evidence with respect to four relevant questions: (1) Are natural or environmental exposures that can disrupt circadian rhythms also related to the switch into high-/low-activation states? (2) Are circadian dysrhythmias (e.g., altered rest/activity rhythms) associated with the switch into activation states in bipolar disorder? (3) Do interventions that affect the circadian system also affect activation states? (4) Are associations between circadian dysrhythmias and activation states influenced by other "third" factors?

RESULTS

Factors that naturally or experimentally alter circadian rhythms (e.g., light exposure) have been shown to relate to activation states; however future studies need to measure circadian rhythms contemporaneously with these natural/experimental factors. Actigraphic measures of circadian dysrhythmias are associated prospectively with the switch into high- or low-activation states, and more studies are needed to establish the most relevant prognostic actigraphy metrics in bipolar disorder. Interventions that can affect the circadian system (e.g., light therapy, lithium) can also reduce the switch into high-/low-activation states. Whether circadian rhythms mediate these clinical effects is an unknown but valuable question. The influence of age, sex, and other confounders on these associations needs to be better characterised.

CONCLUSION

Based on the reviewed evidence, our view is that circadian dysrhythmia is a plausible driver of transitions into high- and low-activation states and deserves prioritisation in research in bipolar disorders.

The Role of Anxiety Sensitivity in the Association Between Childhood Maltreatment and Sleep Disturbance Among Adults in Psychiatric Inpatient Treatment

The present investigation examined associations of childhood maltreatment, anxiety sensitivity (AS), and sleep disturbance among a diverse sample of adults in psychiatric inpatient treatment. We hypothesized that childhood maltreatment would be indirectly associated with greater sleep disturbance through elevated AS. Exploratory analyses examined the indirect effect models with three AS subscales (i.e., physical, cognitive, and social concerns) as parallel mediators. A sample of adults in acute-care psychiatric inpatient treatment (N = 88; 62.5% male; Mage = 33.32 years, SD = 11.07; 45.5% White) completed a series of self-report measures. After accounting for theoretically relevant covariates, childhood maltreatment was indirectly associated with sleep disturbance through AS. Parallel mediation analyses revealed that no individual subscale of AS significantly accounted for this association. These findings suggest that heightened levels of AS may explain the association between childhood maltreatment and sleep disturbance among adults in psychiatric inpatient treatment. Interventions targeting AS can be brief and efficacious and have the potential to improve clinical outcomes among psychiatric populations.

Tryptophan and Substance Abuse: Mechanisms and Impact

Addiction, the continuous misuse of addictive material, causes long-term dysfunction in the neurological system. It substantially affects the control strength of reward, memory, and motivation. Addictive substances (alcohol, marijuana, caffeine, heroin, methamphetamine (METH), and nicotine) are highly active central nervous stimulants. Addiction leads to severe health issues, including cardiovascular diseases, serious infections, and pulmonary/dental diseases. Drug dependence may result in unfavorable cognitive impairments that can continue during abstinence and negatively influence recovery performance. Although addiction is a critical global health challenge with numerous consequences and complications, currently, there are no efficient options for treating drug addiction, particularly METH. Currently, novel treatment approaches such as psychological contingency management, cognitive behavioral therapy, and motivational enhancement strategies are of great interest. Herein, we evaluate the devastating impacts of different addictive substances/drugs on users' mental health and the role of tryptophan in alleviating unfavorable side effects. The tryptophan metabolites in the mammalian brain and their potential to treat compulsive abuse of addictive substances are investigated by assessing the functional effects of addictive substances on tryptophan. Future perspectives on developing promising modalities to treat addiction and the role of tryptophan and its metabolites to alleviate drug dependency are discussed.

Delayed circadian rhythms in older Africans living with human immunodeficiency virus (HIV)

The increasing number of people living with human immunodeficiency virus, HIV, (PLWH) have an elevated incidence of risk for noncommunicable comorbidities, the aetiology of which remains incompletely understood. While sleep disturbances are often reported in PLWH, it is unknown to what extent they relate to changes in the circadian and/or sleep homeostatic processes. We studied the relationship between sleep characteristics, circadian phase, and HIV status in older adults from the HAALSI (Health and Ageing in Africa: a Longitudinal Study of an INDEPTH Community in South Africa) subsample of the Agincourt Health and Demographic Surveillance System in South Africa (n = 187, 36 human immunodeficiency virus positive [HIV+], age: 66.7 ± 11.5 years, range 45-93 years), where HIV prevalence is high and (in contrast to the global north) does not associate significantly with potentially confounding behavioural differences. In participants with valid actigraphy data (n = 172), regression analyses adjusted for age and sex indicated that HIV+ participants had slightly later sleep onset (β = .16, p = .039), earlier sleep offset times (β = -.16, p = .049) and shorter total sleep times (β = -.20, p = .009) compared to the HIV negative (HIV-) participants. In a subset of participants (n = 51, 11 HIV+), we observed a later dim light melatonin onset (DLMO) in HIV+ (21:16 ± 01:47) than in HIV- (20:06 ± 00:58) participants (p = .006). This substantial difference remained when adjusted for age and sex (β = 1.21; p = .006). In 36 participants (6 HIV+) with DLMO and actigraphy data, median phase angle of entrainment was -6 min in the HIV+ group and +1 h 25 min in the HIV- group. DLMO time correlated with sleep offset (ρ = 0.47, p = .005) but not sleep onset (ρ = -0.086, p = .623). Collectively, our data suggest that the sleep phase occurred earlier than what would be biologically optimal among the HIV+ participants. This is the first report of a mistimed circadian phase in PLWH, which has important potential implications for their health and well-being, especially given the well-established relationships between circadian asynchrony and sleep deprivation with poorer health outcomes.

The disruptive relationship among circadian rhythms, pain, and opioids

Pain behavior and the systems that mediate opioid analgesia and opioid reward processing display circadian rhythms. Moreover, the pain system and opioid processing systems, including the mesolimbic reward circuitry, reciprocally interact with the circadian system. Recent work has demonstrated the disruptive relationship among these three systems. Disruption of circadian rhythms can exacerbate pain behavior and modulate opioid processing, and pain and opioids can influence circadian rhythms. This review highlights evidence demonstrating the relationship among the circadian, pain, and opioid systems. Evidence of how disruption of one of these systems can lead to reciprocal disruptions of the other is then reviewed. Finally, we discuss the interconnected nature of these systems to emphasize the importance of their interactions in therapeutic contexts.

Sleep restriction during opioid abstinence affects the hypothalamic-pituitary-adrenal (HPA) axis in male and female rats

Hypothalamic-pituitary-adrenal (HPA) axis dynamics are disrupted by opioids and may be involved in substance abuse; this persists during withdrawal and abstinence and is associated with co-morbid sleep disruption leading to vulnerability to relapse. We hypothesized that chronic sleep restriction (SR) alters the HPA axis diurnal rhythm and the sexually dimorphic response to acute stressor during opioid abstinence. We developed a rat model to evaluate the effect of persistent sleep loss during opioid abstinence on HPA axis dynamics in male and female rats. Plasma ACTH and corticosterone were measured diurnally and in response to acute restraint stress in rats Before (control) compared to During subsequent opioid abstinence without or with SR. Abstinence, regardless of sleep state, led to an increase in plasma ACTH and corticosterone in the morning in males. There was a tendency for higher PM plasma ACTH during abstinence in SR males (p = 0.076). ACTH and corticosterone responses to restraint were reduced in male SR rats whereas there was a failure to achieve the post-restraint nadir in female SR rats. There was no effect of the treatments or interventions on adrenal weight normalized to body weight. SR resulted in a dramatic increase in hypothalamic PVN AVP mRNA and plasma copeptin in male but not female rats. This corresponded to the attenuation of the HPA axis stress response in SR males during opioid abstinence. We have identified a potentially unique, sexually dimorphic role for magnocellular vasopressin in the control of the HPA axis during opioid abstinence and sleep restriction.

Can air purification improve sleep quality? A 2‐week randomised‐controlled crossover pilot study in healthy adults

Insufficient quantity and quality of sleep is a public health concern that can be addressed by interventions for improving sleep outcomes. Environmental factors such as poor air quality are a potential target for intervention, particularly in light of associations between air pollution and worse sleep. The aim of this pilot study was to investigate the effects of using an air purifier on sleep outcomes and mood in 30 healthy adults. There were two conditions: (i) air purifier with a high-efficiency particulate air filter; (ii) air purifier with a placebo filter. Participants undertook both conditions, each over 2 weeks with a 2-week washout, following a counterbalanced, double-blind design. Daily sleep outcomes were measured with actigraphy watches and sleep diaries, whilst daily mood was assessed with the Positive and Negative Affect Schedule. The Insomnia Severity Index, the Pittsburgh Sleep Quality Index, and symptoms of anxiety and depression were measured pre- and post-. The purifier filter was associated with increased total sleep time for an average of 12 min per night, and increased total time in bed for an average of 19 min per night relative to the placebo. There were several sleep and mood outcomes for which no changes were observed, and time awake after sleep onset was higher for the purifier filter. Air quality was better during the high-efficiency particulate air filter condition. These findings offer positive indications that environmental interventions that improve air quality can have benefits for sleep outcomes in healthy populations who are not exhibiting clinical sleep disturbances.

Sleep Disorder and Cocaine Abuse Impact Purine and Pyrimidine Nucleotide Metabolic Signatures

Disturbances in the circadian rhythm alter the normal sleep-wake cycle, which increases vulnerability to drug abuse. Drug abuse can disrupt several homeostatic processes regulated by the circadian rhythm and influence addiction paradigms, including cravings for cocaine. The relationship between circadian rhythm and cocaine abuse is complex and bidirectional, and disruption impacts both brain function and metabolic profiles. Therefore, elucidating the impact of circadian rhythm changes and cocaine abuse on the human metabolome may provide new insights into identifying potential biomarkers. We examine the effect of cocaine administration with and without circadian rhythm sleep disruption (CRSD) on metabolite levels and compare these to healthy controls in an in vivo study. A metabolomics analysis is performed on the control, CRSD, cocaine, and CRSD with cocaine groups. Plasma metabolite concentrations are analyzed using a liquid chromatography electrochemical array platform. We identify 242 known metabolites compared to the control; 26 in the CRSD with cocaine group, 4 in the CRSD group, and 22 in the cocaine group are significantly differentially expressed. Intriguingly, in the CRSD with cocaine treatment group, the expression levels of uridine monophosphate (p < 0.008), adenosine 5′-diphosphate (p < 0.044), and inosine (p < 0.019) are significantly altered compared with those in the cocaine group. In summary, alterations in purine and pyrimidine metabolism provide clues regarding changes in the energy profile and metabolic pathways associated with chronic exposure to cocaine and CRSD.

Measuring Daily Activity Rhythms in Young Adults at Risk of Affective Instability Using Passively Collected Smartphone Data: Observational Study

BACKGROUND

Irregularities in circadian rhythms have been associated with adverse health outcomes. The regularity of rhythms can be quantified using passively collected smartphone data to provide clinically relevant biomarkers of routine.

OBJECTIVE

This study aims to develop a metric to quantify the regularity of activity rhythms and explore the relationship between routine and mood, as well as demographic covariates, in an outpatient psychiatric cohort.

METHODS

Passively sensed smartphone data from a cohort of 38 young adults from the Penn or Children's Hospital of Philadelphia Lifespan Brain Institute and Outpatient Psychiatry Clinic at the University of Pennsylvania were fitted with 2-state continuous-time hidden Markov models representing active and resting states. The regularity of routine was modeled as the hour-of-the-day random effects on the probability of state transition (ie, the association between the hour-of-the-day and state membership). A regularity score, Activity Rhythm Metric, was calculated from the continuous-time hidden Markov models and regressed on clinical and demographic covariates.

RESULTS

Regular activity rhythms were associated with longer sleep durations (P=.009), older age (P=.001), and mood (P=.049).

CONCLUSIONS

Passively sensed Activity Rhythm Metrics are an alternative to existing metrics but do not require burdensome survey-based assessments. Low-burden, passively sensed metrics based on smartphone data are promising and scalable alternatives to traditional measurements.

Associations between sleep patterns, smoking, and alcohol use among older adults in Canada: Insights from the Canadian Longitudinal Study on Aging (CLSA)

Poor sleep is associated with chronic health conditions among older adults. As substance use rates increase in this population, age-related physiological and cognitive declines may exacerbate its detrimental consequences, including sleep problems. We analyzed cross-sectional associations between sleep patterns, smoking, and alcohol use using baseline data from 30,097 community-dwelling Canadian adults aged 45-85 years from the Canadian Longitudinal Study on Aging. Insomnia symptoms (difficulties falling/staying asleep), sleep duration (short:<6h; long:>8h), and sleep satisfaction(dissatisfied/neutral/satisfied) were measured. Smoking and alcohol-use frequency (past 12 months), average daily amount (past 30 days), and binge drinking (past 12 months) were self-reported, and associations were examined using modified Poisson regression. Approximately 23% of participants had insomnia symptoms, and 26% reported sleep dissatisfaction. 91% of participants were current non-smokers, whereas 7% reported smoking daily. Over 50% drank ≤ 2 drinks daily, and 3% reported binge drinking. There was a higher adjusted prevalence of insomnia among daily smokers (PR = 1.10, 95% CI = 1.00-1.21) and binge drinkers (PR = 1.21, 95% CI = 1.02-1.43). Odds of short sleep duration were lower among regular drinkers (COR = 0.71, 95% CI = 0.56-0.90) and higher among daily smokers (COR = 1.19, 95% CI = 1.01-1.40). Heavy and frequent smoking and alcohol use are associated with both insomnia symptoms and sleep dissatisfaction, but not consistently with sleep duration. Further longitudinal investigation of this relationship in aging populations is needed in clinical and public health settings to infer the extent of causality and design effective public health interventions in this vulnerable population.

Associations between specific sleep and circadian characteristics and alcohol use disorder criteria and problems

Given the significant heterogeneity of alcohol use disorder (AUD) and the increasing priority to understand individual profiles of AUD, pursuing symptom-level examinations of AUD is important. Disturbances in sleep and circadian rhythms have demonstrated robust associations with alcohol consumption and AUD, yet little research has examined these associations at the symptom- or problem-levels and research to date has focused on one or two sleep/circadian characteristics. We sought to investigate the associations between (a) specific AUD symptoms and (b) domains of alcohol-related problems, and multiple sleep characteristics, collected at a daily level in the naturalistic environment. Young adult drinkers were recruited from the community (N = 159, Mage = 23.9, 58.5% female, 6.3% Asian, 35.9% Black or African American, 51.6% White, 5.0% multiracial) and completed a baseline visit as well as up to 18 days of naturalistic assessment. Several sleep/circadian characteristics, including eveningness, later midsleep timing, and shorter total sleep time, were consistently associated with the hazardous use symptom, above and beyond alcohol consumption. Eveningness (beta[SE] = 0.21[0.00], p <.01) was a significant predictor of the alcohol-related problem domain of role interference. Exploratory analyses did not find significant associations between sleep/circadian characteristics and cannabis-related problems. The relationship between sleep/circadian characteristics and AUD and related problems may be driven by a narrower set of symptoms, such as hazardous use and role interference. This may be due to shared mechanistic dysfunction in domains such as reward processing or cognitive control. Thus, these alcohol-related symptoms and problems may be addressed through transdiagnostic treatment approaches that target these underlying mechanisms.

Keep Your Mask On: The Benefits of Masking for Behavior and the Contributions of Aging and Disease on Dysfunctional Masking Pathways

Environmental cues (e.g., light-dark cycle) have an immediate and direct effect on behavior, but these cues are also capable of “masking” the expression of the circadian pacemaker, depending on the type of cue presented, the time-of-day when they are presented, and the temporal niche of the organism. Masking is capable of complementing entrainment, the process by which an organism is synchronized to environmental cues, if the cues are presented at an expected or predictable time-of-day, but masking can also disrupt entrainment if the cues are presented at an inappropriate time-of-day. Therefore, masking is independent of but complementary to the biological circadian pacemaker that resides within the brain (i.e., suprachiasmatic nucleus) when exogenous stimuli are presented at predictable times of day. Importantly, environmental cues are capable of either inducing sleep or wakefulness depending on the organism’s temporal niche; therefore, the same presentation of a stimulus can affect behavior quite differently in diurnal vs. nocturnal organisms. There is a growing literature examining the neural mechanisms underlying masking behavior based on the temporal niche of the organism. However, the importance of these mechanisms in governing the daily behaviors of mammals and the possible implications on human health have been gravely overlooked even as modern society enables the manipulation of these environmental cues. Recent publications have demonstrated that the effects of masking weakens significantly with old age resulting in deleterious effects on many behaviors, including sleep and wakefulness. This review will clearly outline the history, definition, and importance of masking, the environmental cues that induce the behavior, the neural mechanisms that drive them, and the possible implications for human health and medicine. New insights about how masking is affected by intrinsically photosensitive retinal ganglion cells, temporal niche, and age will be discussed as each relates to human health. The overarching goals of this review include highlighting the importance of masking in the expression of daily rhythms, elucidating the impact of aging, discussing the relationship between dysfunctional masking behavior and the development of sleep-related disorders, and considering the use of masking as a non-invasive treatment to help treat humans suffering from sleep-related disorders.

The roles of the circadian hormone melatonin in drug addiction

Given the devastating social and health consequences of drug addiction and the limitations of current treatments, a new strategy is needed. Circadian system disruptions are frequently associated with drug addiction. Correcting abnormal circadian rhythms and improving sleep quality may thus be beneficial in the treatment of patients with drug addiction. Melatonin, an essential circadian hormone that modulates the biological clock, has anti-inflammatory, analgesic, anti-depressive, and neuroprotective effects via gut microbiota regulation and epigenetic modifications. It has attracted scientists' attention as a potential solution to drug abuse. This review summarized scientific evidence on the roles of melatonin in substance use disorders at the cellular, circuitry, and system levels, and discussed its potential applications as an intervention strategy for drug addiction.

Characterisation of the genetic relationship between the domains of sleep and circadian-related behaviours with substance use phenotypes

Sleep problems and substance use frequently co-occur. While substance use can result in specific sleep deficits, genetic pleiotropy could explain part of the relationship between sleep and substance use and use disorders. Here we use the largest publicly available genome-wide summary statistics of substance use behaviours (N = 79,729-632,802) and sleep/activity phenotypes to date (N = 85,502-449,734) to (1) assess the genetic overlap between substance use behaviours and both sleep and circadian-related activity measures, (2) estimate clusters from genetic correlations and (3) test processes of causality versus genetic pleiotropy. We found 31 genetic correlations between substance use and sleep/activity after Bonferroni correction. These patterns of overlap were represented by two genetic clusters: (1) tobacco use severity (age of first regular tobacco use and smoking cessation) and sleep health (sleep duration, sleep efficiency and chronotype) and (2) substance consumption/problematic use (drinks per day and cigarettes per day, cannabis use disorder, opioid use disorder and problematic alcohol use) and sleep problems (insomnia, self-reported short sleep duration, increased number of sleep episodes, increased sleep duration variability and diurnal inactivity) and measures of circadian-related activity (L5, M10 and sleep midpoint). Latent causal variable analyses determined that horizontal pleiotropy (rather than genetic causality) underlies a majority of the associations between substance use and sleep/circadian related measures, except one plausible genetically causal relationship for opioid use disorder on self-reported long sleep duration. Results show that shared genetics are likely a mechanism that is at least partly responsible for the overlap between sleep and substance use traits.

Astrocyte Molecular Clock Function in the Nucleus Accumbens Is Important for Reward-Related Behavior

BACKGROUND

Substance use disorders are associated with disruptions in circadian rhythms. Both human and animal work have shown the integral role for circadian clocks in the modulation of reward behaviors. Astrocytes have emerged as key regulators of circadian rhythmicity. However, no studies to date have identified the role of circadian astrocyte function in the nucleus accumbens (NAc), a hub for reward regulation, or determined the importance of these rhythms for reward-related behavior.

METHODS

Using astrocyte-specific RNA sequencing across time of day, we first characterized diurnal variation of the NAc astrocyte transcriptome. We then investigated the functional significance of this circadian regulation through viral-mediated disruption of molecular clock function in NAc astrocytes, followed by assessment of reward-related behaviors, metabolic-related molecular assays, and whole-cell electrophysiology in the NAc.

RESULTS

Strikingly, approximately 43% of the astrocyte transcriptome has a diurnal rhythm, and key metabolic pathways were enriched among the top rhythmic genes. Moreover, mice with a viral-mediated loss of molecular clock function in NAc astrocytes show a significant increase in locomotor response to novelty, exploratory drive, operant food self-administration, and motivation. At the molecular level, these animals also show disrupted metabolic gene expression, along with significant downregulation of both lactate and glutathione levels in the NAc. Loss of NAc astrocyte clock function also significantly altered glutamatergic signaling onto neighboring medium spiny neurons, alongside upregulated glutamate-related gene expression.

CONCLUSIONS

Taken together, these findings demonstrate a novel role for astrocyte circadian molecular clock function in the regulation of the NAc and reward-related behaviors.

The 24-hour rhythm in alcohol craving and individual differences in sleep characteristics and alcohol use frequency

BACKGROUND

Evidence implicates sleep/circadian factors in alcohol use, suggesting the existence of a 24-h rhythm in alcohol craving, which may vary by individual differences in sleep factors and alcohol use frequency. This study sought to (1) replicate prior findings of a 24-h rhythm in alcohol craving, and (2) examine whether individual differences in sleep timing, sleep duration, or alcohol use frequency are related to differences in the timing of the peak of the craving rhythm (i.e., the acrophase) or magnitude of fluctuation of the rhythm (i.e., amplitude). Finally, whether such associations varied by sex or racial identity was explored.

METHODS

Two-hundred fifteen adult drinkers (21 to 35 years of age, 72% male, 66% self-identified as White) completed a baseline assessment of alcohol use frequency and then smartphone reports of alcohol craving intensity six times a day across 10 days. Sleep timing was also recorded each morning of the 10-day period. Multilevel cosinor analysis was used to test the presence of a 24-h rhythm and to estimate acrophase and amplitude.

RESULTS

Multilevel cosinor analysis revealed a 24-h rhythm in alcohol craving. Individual differences in sleep timing or sleep duration did not predict rhythm acrophase or amplitude. However, alcohol use frequency moderated this rhythm wherein individuals who used alcohol more frequently in the 30 days prior to beginning the study had higher mean levels of craving and greater rhythm amplitudes (i.e., greater rhythmic fluctuations). Associations did not vary by sex or racial identity.

CONCLUSIONS

Results show that alcohol craving exhibits a systematic rhythm over the course of the 24 h and that the frequency of alcohol use may be relevant to the shape of this rhythm. Consideration of daily rhythms in alcohol craving may further our understanding of the mechanisms that drive alcohol use.

The Ventral Tegmental Area and Nucleus Accumbens as Circadian Oscillators: Implications for Drug Abuse and Substance Use Disorders

Circadian rhythms convergently evolved to allow for optimal synchronization of individuals’ physiological and behavioral processes with the Earth’s 24-h periodic cycling of environmental light and temperature. Whereas the suprachiasmatic nucleus (SCN) is considered the primary pacemaker of the mammalian circadian system, many extra-SCN oscillatory brain regions have been identified to not only exhibit sustainable rhythms in circadian molecular clock function, but also rhythms in overall region activity/function and mediated behaviors. In this review, we present the most recent evidence for the ventral tegmental area (VTA) and nucleus accumbens (NAc) to serve as extra-SCN oscillators and highlight studies that illustrate the functional significance of the VTA’s and NAc’s inherent circadian properties as they relate to reward-processing, drug abuse, and vulnerability to develop substance use disorders (SUDs).

Early-Life Sleep Deprivation Enhanced Alcohol Consumption in Adolescent Rats

Evidence in the literature suggests that sleep deprivation during early-life developmental stages, by impacting important processes such as the reward circuit maturation, may increase the vulnerability for alcohol and substance use. The mechanisms involved are not fully understood. In this study, utilizing our previously established model, we examined the impact of early-life sleep deprivation on alcohol consumption in adolescent rats. Male Sprague Dawley rats served as either the control (CON) or sleep-deprived (SD) group. Sleep deprivation was induced using a Pinnacle automated sleep deprivation apparatus. The SD group of rats was sleep deprived for 6–8 h/day for 14 days from postnatal day (PND)19 to PND32. At PND33, anxiety- and depression-like behaviors were assessed in rats using elevated plus maze and sucrose splash test, respectively. At PND39, alcohol consumption was assessed in rats for five consecutive days using the two-bottle choice paradigm, water versus 5% ethanol. SD rats exhibited significant anxiety- and depression-like behaviors as compared to CON rats. Interestingly, SD rats consumed a larger volume of alcohol when compared to CON rats, which was significantly higher at day 5 (mean of alcohol consumption (ml) ± SD; CON = 6.67 ± 3.42; SD = 19.00 ± 6.05, p = 0.0126). SD rats also showed high preference for alcohol over water, which was significantly higher at day 5 (mean of alcohol preference (%) ± SD; CON = 26.85 ± 14.97; SD = 57.69 ± 5.61, p = 0.014). Our data suggest that early-life sleep deprivation enhanced alcohol consumption in adolescent rats.

Sleep Quality in Neuromyelitis Optica Spectrum Disorder: A Systematic Review

BACKGROUND

This review summarizes the literature on sleep quality in neuromyelitis optica spectrum disorder (NMOSD) and discusses these findings in the context of current knowledge of sleep physiology.

METHODS

A literature search was performed using Ovid MEDLINE, Embase, and Scopus from inception to September 3, 2020. All included studies reported at least 1 measure of sleep quality in individuals with NMOSD. Pittsburgh Sleep Quality Index (PSQI) scores of individuals from 4 studies were compared with those from a data set of controls.

RESULTS

Thirteen studies (1041 individuals with NMOSD) were included in the review. Disturbed sleep was demonstrated across subjective metrics based on patient surveys and objective metrics such as polysomnography. An estimated 70% of individuals with NMOSD can be classified as poor sleepers. Standardized mean difference between PSQI scores of 183 individuals with NMOSD and those of 9284 controls was 0.72 (95% CI, 0.57-0.86; P < .001). Decreased sleep quality was significantly associated with decreased quality of life and increased anxiety, depression, and disability status. Sleep disturbances in NMOSD were similar in severity to those in multiple sclerosis.

CONCLUSIONS

Sleep disturbances are a major contributor to NMOSD disease burden and may arise from the disruption of sleep circuitry, in addition to physical and psychological complications. Multiple processes involved in sleep regulation may be affected, such as, but not limited to, neural circadian circuit disruption, direct effects of inflammation, aminergic projecting system abnormalities, glymphatic system impairment, and development of sleep disorders such as restless legs syndrome/sleep apnea. A better understanding of these mechanisms is necessary for developing effective therapies for NMOSD-associated sleep disturbances.

Adult ADHD and sleep disorders: Prevalence, severity and predictors of sleep disorders in a sample of Italian psychiatric outpatients

OBJECTIVE

Sleep disorders are frequent in adult subjects diagnosed with ADHD. The aims of the present study were to assess the prevalence and the severity of sleep disorders in a sample of Italian psychiatric outpatients, to compare the prevalence and severity of sleep disorders in patients with and without diagnosis of adult ADHD, and to evaluate the role of ADHD as an individual predictor of sleep disturbances severity.

METHOD

634 outpatients accessing psychiatric services were assessed with the Mini-International Neuropsychiatric Interview (MINI) Plus V. 5.0.0 interview and the Adult ADHD self-report Scale Symptoms Checklist (ASRS)-V 1.1 Short Form. Patients positive to the ASRS-V 1.1 were assessed with the Diagnostic Interview for ADHD in Adults (DIVA) 2.0. Sleep disorders and sleep disturbances' severity were assessed with the PROMIS Adult Sleep Disturbance Scale.

RESULTS

Sleep disorders were more frequent (p < 0.001) and sleep disturbances were more severe (d = 1.26, p < 0.001) in subjects diagnosed with adult ADHD compared to other outpatients. Among the 44 subjects diagnosed with ADHD, 15 (34.1%) reported no or slight sleep disturbances, 9 (20.5%) a mild sleep disorder, 17 (38.6%) a moderate sleep disorder and 3 (6.8%) a severe sleep disorder. ADHD diagnosis, multiple psychiatric comorbidity and history of suicide attempts emerged as individual predictors of worse sleep disturbances.

CONCLUSION

Sleep disorders are more frequent and severe in subjects diagnosed with ADHD compared to other adult outpatients. Sleep disturbances might represent an intrinsic feature in adult ADHD subjects, presenting important clinical repercussions, and should be routinely evaluated and monitored in this population.

Dopamine D2 receptor signaling in the brain modulates circadian liver metabolomic profiles

SignificanceWe analyzed the liver metabolome of mice deficient in the expression of the dopamine D2 receptor (D2R) in striatal medium spiny neurons (iMSN-D2RKO) and found profound changes in the liver circadian metabolome compared to control mice. Additionally, we show activation of dopaminergic circuits by acute cocaine administration in iMSN-D2RKO mice reprograms the circadian liver metabolome in response to cocaine. D2R signaling in MSNs is key for striatal output and essential for regulating the first response to the cellular and rewarding effects of cocaine. Our results suggest changes in dopamine signaling in specific striatal neurons evoke major changes in liver physiology. Dysregulation of liver metabolism could contribute to an altered allostatic state and therefore be involved in continued use of drugs.

Circadian transcription factor NPAS2 and the NAD+ -dependent deacetylase SIRT1 interact in the mouse nucleus accumbens and regulate reward

Substance use disorders are associated with disruptions to both circadian rhythms and cellular metabolic state. At the molecular level, the circadian molecular clock and cellular metabolic state may be interconnected through interactions with the nicotinamide adenine dinucleotide (NAD⁺ )-dependent deacetylase, sirtuin 1 (SIRT1). In the nucleus accumbens (NAc), a region important for reward, both SIRT1 and the circadian transcription factor neuronal PAS domain protein 2 (NPAS2) are highly enriched, and both are regulated by the metabolic cofactor NAD⁺ . Substances of abuse, like cocaine, greatly disrupt cellular metabolism and promote oxidative stress; however, their effects on NAD⁺ in the brain remain unclear. Interestingly, cocaine also induces NAc expression of both NPAS2 and SIRT1, and both have independently been shown to regulate cocaine reward in mice. However, whether NPAS2 and SIRT1 interact in the NAc and/or whether together they regulate reward is unknown. Here, we demonstrate diurnal expression of Npas2, Sirt1 and NAD⁺ in the NAc, which is altered by cocaine-induced upregulation. Additionally, co-immunoprecipitation reveals NPAS2 and SIRT1 interact in the NAc, and cross-analysis of NPAS2 and SIRT1 chromatin immunoprecipitation sequencing reveals several reward-relevant and metabolic-related pathways enriched among shared gene targets. Notably, NAc-specific Npas2 knock-down or a functional Npas2 mutation in mice attenuates SIRT1-mediated increases in cocaine preference. Together, our data reveal an interaction between NPAS2 and SIRT1 in the NAc, which may serve to integrate cocaine's effects on circadian and metabolic factors, leading to regulation of drug reward.

REM sleep deprivation before extinction or reinstatement alters methamphetamine reward memory via D1-like dopamine receptors

We aimed to determine whether REM sleep deprivation (RSD) affects extinction and reinstatement of methamphetamine (METH) reward memory in male rats and also to evaluate the possible role of dopamine D1-like and D2-like dopamine (DA) receptors in these processes. Male rats were trained to acquire METH-induced place preference (2 mg/kg, i.p.). METH reward memory was then reinstated following a 10-day extinction period. The animals underwent a 72-hour sleep deprivation episode by multiple platforms method (in separate groups), either before the extraction or before the reinstatement of METH reward memory. The animals received SCH 23390 (0.01 or 0.05 mg/kg, i.p.) or sulpiride (20 or 60 mg/kg, i.p.) as antagonists of D1-like and D2-like DA receptors, respectively, either immediately following each daily extinction session or before the reinstatement of METH-seeking behavior. The RSD episode postponed extinction and facilitated reinstatement of METH reward memory. Administration of SCH 23390, but not sulpiride, facilitated METH extinction and decreased reinstatement of the extinguished METH-seeking behavior. Moreover, locomotor activity was not affected by METH and/or the RSD paradigm. The results would seem to suggest that the D1-like, but not the D2-like, DA receptors may be involved in the extinction and reinstatement of the extinguished METH reward memory in RSD animals. Nonetheless, more investigations are needed to elucidate the exact mechanisms involved.

Comparing the Effects of Melatonin and Zolpidem on Mental Health and Sexual Function in Men With Opioid Addiction: Evidence From a Randomized Clinical Trial

BACKGROUND

Mental health problems and impaired sexual function are widely reported among those suffering from drug abuse, particularly among those under methadone maintenance therapy (MMT).

AIMS

The current study aimed to, firstly, investigate the effect of melatonin and zolpidem on mental health and sexual function of those with drug abuse under MMT, and, secondly, to compare the effects of melatonin and zolpidem on the studied outcomes.

METHODS

The current randomized, single-blind, placebo-controlled clinical trial was conducted on 98 participants who were randomly assigned into three groups of melatonin (n = 34), zolpidem (n = 32), and placebo (n = 32). All participants received the intervention once a day for 30 days, without changes in nutrition. Mental health and sexual function were measured before and 30 days after the intervention.

RESULTS

The mean age of participants in the groups of melatonin, zolpidem, and placebo was 35.8 ± 9.6 years (22-58 years of old), 35.9 ± 9.3 years (21-58), and 37.2 ± 7.8 years (26-53), respectively. Sexual function mean score was significantly increased from 38 to 41 in the melatonin group, while it deceased in zolpidem (from 39.1 to 38) and placebo (39.25-38.59) groups. Also, mental health mean scores improved statistically significantly in the melatonin group (from 60.65 to 43.56; p = 0.002), and descriptively in the zolpidem group (57.88-51.18; p = 0.129). Concerning both outcomes, the observed improvement was considerably higher in the melatonin group. The highest improvement was observed in dimensions of overall satisfaction and depression in the melatonin group (1.18 and -8.4, respectively).

CONCLUSION

Melatonin could significantly improve both mental health and some domains of sexual function of those with drug abuse under MMT, while zolpidem did not show a significant effect.

TRIAL REGISTRATION NUMBER

https://www.irct.ir/trial/53047, identifier: IRCT20201214049718N1.

Poor Sleep Quality and Factors Among Reproductive-Age Women in Southwest Ethiopia

BACKGROUND

Adequate sleep is vital for physical and mental wellbeing. Sleep-related problems including poor quality of sleep have been increasing throughout the world among reproductive-aged women. Poor sleep quality has been related with number of diseases and health problems However, evidences are scarce regarding poor sleep quality and its associated factors among women of the reproductive age group in Ethiopia.

OBJECTIVE

To assess sleep quality and associated factors among women of reproductive age group in Mizan Aman town, Southwest Ethiopia.

METHOD

Community-based cross-sectional study was conducted among 606 reproductive-aged women from 06 November to 20 December 2020, in Mizan Aman town. Data were collected using structured interview administered questionnaires. Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. Multivariable logistic regression was applied using an adjusted odds ratio with a corresponding 95% confidence interval to evaluate the statistical significance of associated factors.

RESULT

The overall prevalence of poor sleep quality was 71.3%. The late age group of 42-49 (AOR, 95% CI; 1.21 (1.08-5.76), palpable/visible thyroid gland (AOR, 95% CI; 2. 12 (1.08-3.82), current substance use (AOR, 95% CI; 1.76 (1.11-6.10) and having premenstrual syndrome (AOR, 95% CI; 1.86 (1.38-3.12) were significantly associated with poor sleep quality among reproductive age group women.

CONCLUSION

Significant majority of reproductive age group women faced poor sleep quality. Therefore, screening of sleep patterns among this particular age group is warranted. Moreover, education about sleep hygiene needs to be given considering the identified factors to improve sleep quality.

Insomnia and other sleep disorders in dermatology patients: A questionnaire-based study with 634 patients

Insufficient sleep duration and quality are associated with various adverse health outcomes. Whereas sleep disorders have been studied in a few skin conditions, data in a more comprehensive dermatology population are lacking. We sought to describe the prevalence, causes, and consequences of sleep disorders in dermatology patients. In this cross-sectional, single-center study, dermatology patients completed a questionnaire addressing skin-related and non-skin-related health, sleep behavior, causes, and consequences of sleep disorders. According to the Regensburg Insomnia Scale, 27.92% of the 634 participants had insomnia (177 of 634 patients). Of these 177 patients, 115 (64.97%) were subjectively sleep disturbed, with skin-related causes accounting for 55.65% (64 of 115 patients), non-skin-related accounting for 33.04% (38 of 115 patients), and combined accounting for 11.30% (13 of 115 patients). Itch was the leading cause of skin-related sleep disorders (64.49%, 50 of 77 patients), followed by skin-related pain (55.84%, 43 of 77 patients) and skin-related fearful thoughts (54.55%, 42 of 77 patients). Sleep disorders reduced daytime performance in 68.70% (79 of 115 patients) and sleep quality of relatives in 20.87% (24 of 115 patients). The prevalence of insomnia among different diagnostic categories ranged from 20.31% to 50.00%. The most common strategy to improve sleep was taking sleep medication (57.39%, 66 of 115 patients). We conclude that sleep disorders are highly prevalent in dermatology patients, often leading to reduced daytime performance, impaired sleep among the patients' relatives, and increased use of substances.

Factors modulating the incubation of drug and non-drug craving and their clinical implications

It was suggested in 1986 that cue-induced cocaine craving increases progressively during early abstinence and remains high during extended periods of time. Clinical evidence now supports this hypothesis and that this increase is not specific to cocaine but rather generalize across several drugs of abuse. Investigators have identified an analogous incubation phenomenon in rodents, in which time-dependent increases in cue-induced drug seeking are observed after abstinence from intravenous drug or palatable food self-administration. Incubation of craving is susceptible to variation in magnitude as a function of biological and/or the environmental circumstances surrounding the individual. During the last decade, the neurobiological correlates of the modulatory role of biological (sex, age, genetic factors) and environmental factors (environmental enrichment and physical exercise, sleep architecture, acute and chronic stress, abstinence reinforcement procedures) on incubation of drug craving has been investigated. In this review, we summarized the behavioral procedures adopted, the key underlying neurobiological correlates and clinical implications of these studies.

Assessing sleep problems and daytime functioning: a translation, adaption, and validation of the Athens Insomnia Scale for non-clinical application (AIS-NCA)

OBJECTIVE & DESIGN

Sleep problems are common and have been linked to health problems, diminished well-being, and impaired performance. Many scales to diagnose clinically relevant sleep problems are time-consuming, complex, and difficult to administer in non-clinical and multi-thematic studies. Through a multi-stage translation (from English to German) and scale testing process, we developed a parsimonious measure of sleep problems and daytime functioning for non-clinical applications based on the Athens Insomnia Scale. Results: Exploratory (N_{Study 1} = 25,140) and confirmatory (N_{Study 2} = 14,797) factor analyses suggest a two-dimensional structure with the subscales "sleep problems" and "daytime functioning". Internal scale consistency was acceptable. Measurement invariance was found across time, gender, age, and diagnosed sleep disorders. The scale discriminates between people with and without sleep disorders and predicts emerging sleep disorders. Short-term retest reliability was acceptable (N_{Study 3} = 78). Convergent validity with other sleep measures and discriminant validity with indicators of well-being were observed (N_{Study 4} = 341). After a multi-stage translation to English, we confirmed the factor structure and found measurement invariance across languages (N_{Study 5} = 623). Conclusion: Our short 7-item scale has good psychometric properties and is suitable for self-administration, making it useful in measuring sleep problems and daytime functioning efficiently and reliably, especially for large population studies.

Sleep, psychiatric and socioeconomic factors associated with substance use in a large population sample: A cross-sectional study

Multiple elements modulate drug use, including sleep, which is increasingly being considered as an important contributor to substance use and abuse. The present study aimed to evaluate the association between sleep, psychiatric and socioeconomic/demographic factors and substance use in a large-scale representative sample from the city of São Paulo, Brazil. Data from the 2007 São Paulo Epidemiological Sleep Study (EPISONO) database were used. In the EPISONO study, volunteers underwent a polysomnographic exam and completed a series of questionnaires to assess objective and subjective sleep quality and associated comorbidities. Drug use was assessed using the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST). Linear (univariate and multivariate) and logistic regressions were performed to identify factors associated with the use of the 4 most commonly used substances in the sample (tobacco, alcohol, cannabis and cocaine/crack). Structural equation models were used to establish theoretical networks to explain the relationship between sleep, psychiatric and socioeconomic factors and use of these substances. The logistic regression results showed that psychiatric symptoms, lower income, and poorer subjective sleep were the main factors associated with tobacco consumption; gender and occupational status with alcohol intake; age and occupation with cannabis use; and education with cocaine/crack use. The structural equation models partially supported these findings and identified significant effects of psychiatric symptoms on tobacco consumption, both directly and mediated by sleep. Our results reinforce previous findings concerning factors associated with generally misused substances and suggest that sleep should be considered as an important element in future substance use disorder studies.

Neuroscience-Informed Psychoeducation for Recovery: A Program to Promote Metacognition in People With Substance Use Disorders

Introduction:

A brief neuroscience-informed psychoeducation program (Neuroscience-Informed Psychoeducation for Recovery [NIPER]) was developed to promote awareness (metacognition) in the main cognitive domains affected by drug and alcohol use to increase willingness to invest time and effort in the brain and cognition recovery process. The primary aim of this pilot study was to determine the feasibility and acceptability of the NIPER program and its potential effectiveness in increasing metacognition, psychological wellbeing, and willingness for the brain and cognition recovery programs among patients with Substance Use Disorders (SUDs).

Methods:

A total of 56 patients with SUDs were recruited from four outpatient treatment centers in Tehran City, Iran. They participated in four 90-min weekly sessions delivered adjunct to their routine treatment. The program’s effectiveness was measured in terms of metacognition and psychological wellbeing at baseline and the end of the program. The rate of adherence and participation and willingness to continue with brain and cognition recovery programs were measured as feasibility outcomes.

Results:

A total of 51 participants completed the study. Compared to the baseline assessments, patients reported more problems in dimensions of attention, memory, inhibitory control, decision making, motor/speech, interoception, insight, and a higher level of psychological wellbeing (t=4.66; P<0.001). In terms of feasibility outcomes, the adherence and participation rates were found above 85%. Most participants expressed their high willingness to continue the brain and cognition recovery programs (86.2%) and would introduce NIPER to their peers (98%).

Conclusion:

Considering the pilot results in terms of feasibility and preliminary effectiveness of NIPER in the clinical context of addiction treatment, we think that NIPER is a potentially beneficial intervention to be offered to people with SUD. It would increase their awareness and engage them in the brain and cognition recovery process. However, the clinical efficacy of the intervention should be tested in future randomized clinical trials.

Adverse social experiences in adolescent rats result in persistent sex-dependent effects on alcohol-seeking behavior

BACKGROUND

Accumulating clinical evidence suggests that women with prior exposure to adverse childhood experiences are more susceptible to heavy drinking and other health-related behaviors. Yet, preclinical studies investigating sex-dependent effects of adolescent adverse social experiences (ASEs) on later alcohol-seeking behavior are lacking. This is mainly due to the unavailability of valid animal models and a shortage of studies that compare effects in males and females. Therefore, we sought to investigate the sex-dependent effects of ASE on adult alcohol-seeking behavior, locomotion, and reward sensitivity in male and female rats.

METHODS

We recently developed a rat model for childhood/adolescent peer rejection that allows us to study the long-term consequences of ASEs. Adolescent Wistar rats were reared from postnatal day (pd) 21 to pd 50 either within a group of Fischer 344 rats (ASE) or within a group of Wistar rats (control). Wistar rats housed with Fischer 344 rats do not reciprocate social play in adolescence. This reduced play across adolescence mimics peer rejection and results in chronic dysregulation of social and pain-related behaviors. We tested adult male and female rats in the reinstatement paradigm for cue-induced alcohol-seeking behavior, circadian locomotor activity, and sucrose consumption long after the termination of the peer rejection condition.

RESULTS

Peer rejection induced persistent sex-dependent changes in alcohol cue-induced reinstatement. Females showed an increased reinstatement effect while peer-rejected males demonstrated a decrease. Sex differences were observed in locomotor activity or reward sensitivity to sucrose.

CONCLUSIONS

Peer rejection has long-lasting sex-dependent consequences on alcohol-seeking behavior without affecting locomotion or sweet reward sensitivity. Our results suggest that peer-rejected female rats represent a vulnerable population in which to study relapse-like behaviors that are similar to clinical findings, while males seem to buffer the peer rejection effect and demonstrate resilience to later life alcohol-seeking behaviors, as measured by the reinstatement effect. Finally, we provide a novel approach to investigate the molecular and neurobiological underpinnings of ASEs on alcohol and other drug-seeking behaviors.