Sleep and alcohol use among young adult drinkers with Insomnia: A daily process model

Alcohol Use Predicts Longer But More Fragmented Sleep: A Daily Diary Study of Alcohol, Sleep, and PTSD in Nurses

BACKGROUND

Due to the demanding nature of their profession, nurses are at risk of experiencing irregular sleep patterns, substance use, and fatigue. Evidence supports a reciprocal relationship between alcohol use and sleep disturbances; however, no research has examined such a link in a sample of nurses. One factor that may further impact the dynamic between alcohol and sleep patterns is posttraumatic stress disorder (PTSD) symptoms. We investigated the daily bidirectional associations between alcohol use and several sleep domains (i.e., self-report and actigraphy-determined sleep), and moderation by baseline PTSD symptom severity.

METHOD

Over a 14-day period, 392 nurses (92% female; 78% White) completed sleep diaries and actigraphy to assess alcohol use and sleep patterns. Within-person bidirectional associations between alcohol and sleep were examined using multilevel models, with symptoms of PTSD as a cross-level moderator.

RESULTS

Daily alcohol use (i.e., ≥ 1 alcoholic beverage; 25.76%) was associated with shorter self-reported sleep onset latency (b = -4.21, p = .003) but longer self-reported wake after sleep onset (b = 2.36, p = .009). Additionally, days with any alcohol use were associated with longer self-reported sleep duration (b = 15.60, p = .006) and actigraphy-determined sleep duration (b = 10.06, p = .037). No sleep variables were associated with next-day alcohol use. Bidirectional associations between alcohol consumption and sleep were similar regardless of baseline PTSD symptoms.

CONCLUSION

Our results suggested that on days when nurses drank alcohol, they experienced longer but also more fragmented sleep.

A test of competing mediators linking trouble sleeping to cannabis use in adolescents and emerging adults

This study examined day-level associations between trouble sleeping and three cannabis-use indices (likelihood/quantity of use and impaired control). We evaluated behavioral and cognitive mediators of the association between trouble sleeping and cannabis outcomes. Youth (N = 86, ages 15-24, 48.8% female, 58.8% White, 18.6% Latine) who regularly used cannabis were recruited for an intervention study. This preregistered secondary data analysis leveraged data from a 1-week ecological momentary assessment (EMA) study completed prior to intervention. Trouble sleeping, cannabis use, and impaired control over use were assessed each morning; negative affect, risk-taking propensity, and cannabis craving were assessed multiple times and aggregated to create a daily average. Multilevel structural equation modeling evaluated hypothesized temporally sequenced associations and putative mechanisms at the day (i.e., within) and person (i.e., between) level. In bivariate analyses at the person level, there were large-effect associations between trouble sleeping and craving and negative affect, and between craving and cannabis-use likelihood and quantity (rs from .34 to .48). In multilevel analyses at the day level, participants were less likely to use cannabis the next day after reporting more trouble sleeping (β = -.65, p < .001). Trouble sleeping was not directly associated with subsequent cannabis-use quantity or impaired control, or indirectly via negative affect, risk-taking propensity, or craving. Trouble sleeping had differential relations with cannabis-use indices at the day and person levels. To promote youth health and reduce cannabis use, future research may consider the unique, person- and situation-driven mechanistic processes at play. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

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.

Single use of psychoactive substances and its association with sleep disorders and sleep health in a large US college sample

OBJECTIVE

Estimate the association between single (i.e., exclusive) use of a range of substances and sleep outcomes.

PARTICIPANTS

College students participated in the 2015-2019 American College-Health Association-National College-Health Assessment survey.

METHODS

Multivariable logistic and linear regressions were used.

RESULTS

Single users of sedative, opioid, tobacco, and stimulant drugs were more likely to report a diagnosis of insomnia and other sleep disorder and indicated more days per week of negative sleep health outcomes compared not only to non-users of these substances but also polysubstance users. Single users of alcohol were significantly less likely to report a diagnosis of sleep disorder and indicated having had more days per week of positive sleep health outcomes compared to non-alcohol users and polysubstance users. However, those results are reversed for binge drinking.

CONCLUSIONS

Support of programs addressing behaviors to reduce the high prevalence of psychoactive substance use and sleep disturbances in college youth is needed.

Association between alcohol consumption and sleep traits: observational and mendelian randomization studies in the UK biobank

Previous studies have shown that excessive alcohol consumption is associated with poor sleep. However, the health risks of light-to-moderate alcohol consumption in relation to sleep traits (e.g., insomnia, snoring, sleep duration and chronotype) remain undefined, and their causality is still unclear in the general population. To identify the association between alcohol consumption and multiple sleep traits using an observational and Mendelian randomization (MR) design. Observational analyses and one-sample MR (linear and nonlinear) were performed using clinical and individual-level genetic data from the UK Biobank (UKB). Two-sample MR was assessed using summary data from genome-wide association studies from the UKB and other external consortia. Phenotype analyses were externally validated using data from the National Health and Nutrition Examination Survey (2017-2018). Data analysis was conducted from January 2022 to October 2022. The association between alcohol consumption and six self-reported sleep traits (short sleep duration, long sleep duration, chronotype, snoring, waking up in the morning, and insomnia) were analysed. This study included 383,357 UKB participants (mean [SD] age, 57.0 [8.0] years; 46% male) who consumed a mean (SD) of 9.0 (10.0) standard drinks (one standard drink equivalent to 14 g of alcohol) per week. In the observational analyses, alcohol consumption was significantly associated with all sleep traits. Light-moderate-heavy alcohol consumption was linearly linked to snoring and the evening chronotype but nonlinearly associated with insomnia, sleep duration, and napping. In linear MR analyses, a 1-SD (14 g) increase in genetically predicted alcohol consumption was associated with a 1.14-fold (95% CI, 1.07-1.22) higher risk of snoring (P < 0.001), a 1.28-fold (95% CI, 1.20-1.37) higher risk of evening chronotype (P < 0.001) and a 1.24-fold (95% CI, 1.13-1.36) higher risk of difficulty waking up in the morning (P < 0.001). Nonlinear MR analyses did not reveal significant results after Bonferroni adjustment. The results of the two-sample MR analyses were consistent with those of the one-sample MR analyses, but with a slightly attenuated overall estimate. Our findings suggest that even low levels of alcohol consumption may affect sleep health, particularly by increasing the risk of snoring and evening chronotypes. The negative effects of alcohol consumption on sleep should be made clear to the public in order to promote public health.

Influence of sleep quality on lapse to alcohol use during a quit attempt

AIMS

Sleep problems are common among individuals with alcohol use disorder (AUD) and is often associated with a heightened relapse risk. The present study examines the relationship between sleep and alcohol use among individuals with current AUD during a 6-day quit attempt as part of a medication study.

METHODS

The current study is a secondary analysis of a medication trial for individuals with AUD. Individuals with AUD (N = 53, 26 females) were randomized to active medication or matched placebo. Randomized participants completed a week-long medication titration (Days 1-7). Following the titration period, participants attended an in-person visit (Day 8) to begin a 6-day quit attempt. During the quit attempt, participants completed daily diary assessments to report on previous day alcohol consumption, sleep quality, and alcohol craving. In the present study, medication condition was controlled for in all models.

RESULTS

Baseline global sleep quality was not a significant predictor of drinks per drinking day (P = 0.72) or percent days abstinent (P = 0.16) during the 6-day practice quit attempt. Daily diary analyses found that greater sleep quality was associated with higher next-day drinks per drinking day (b = 0.198, P = 0.029). In contrast, participants reported worse sleep quality following nights of greater alcohol intake, albeit at a trend-level (b = -0.12, P = 0.053).

CONCLUSIONS

These results suggest that better sleep quality was a risk factor for drinking during the 6-day quit period, such that better sleep may be associated with increased craving for alcohol and alcohol use the next day. These findings are limited to the early abstinence period and should be considered in studies exploring longer periods of abstinence.

Sleep and circadian hygiene practices association with sleep quality among Brazilian adults

Objective

To investigate the association of sleep and circadian hygiene practices (sleep-promoting and sleep-disturbing behaviors) with sleep quality indicators.

Methods

Participants (n = 2050; 18-65 y) were part of virtual population-based research. Logistic regression models were fitted to assess differences in the OR (95% CI) of poor quality with sleep-promoting/disturbing practices (time-of-day of exercise, pre-bedtime routine, naps, electronic devices with illuminated screens, caffeine and alcohol consumption, and smoking). Linear regression analyses evaluated differences in sleep duration, latency, and awakenings associated with the same variables. Restricted cubic splines were used to study the shape of the association of screen time before bed with sleep duration, latency, and awakenings. Analyses were adjusted for age, sex, region, marital status, educational level, evening diet quality, and BMI.

Results

Evening use of electronic devices with illuminated screens showed a negative effect on all sleep parameters. Reporting dinner as the largest meal and evening caffeine consumption was associated with shorter sleep duration and longer sleep latency. Smokers had higher odds of longer latency. A protective effect of morning exercises was demonstrated on sleep quality, latency, and awakenings. Alcohol consumers presented lower odds of poor quality and lower frequency of awakenings. Pre-bedtime practices showed no or negative effect on sleep outcomes.

Conclusions

Recommendations to promote sleep quality and prevent sleep-related problems, with corresponding circadian health benefits, should include engaging in regular exercise, preferably in the morning, and avoiding naps, heavy meals close to bedtime, caffeine, smoking, and evening screen exposure.

Leveraging Ecological Momentary Assessment to Examine Bi-directional Associations Between Sleep Quality, Adolescent/Young Adult Alcohol Craving and Use

BACKGROUND

Alcohol use is common among adolescents and young adults (AYA) and linked to poor sleep quality. Poor sleep quality may also increase alcohol use and alcohol craving, yet bi-directional relations between sleep quality and AYA alcohol use are poorly understood.

PURPOSE

This study examined bi-directional associations between sleep quality, alcohol craving, and alcohol use in AYA using ecological momentary assessment (EMA) and explored if biological sex, age, or race moderated these associations.

METHODS

This pre-registered secondary analysis pooled EMA data from the baseline, pre-randomization period (M = 8.18 days, range = 1-17) in two double-blind randomized placebo-controlled clinical trials examining medication effects on alcohol use in AYA (N = 115). Each morning, participants reported sleep quality and alcohol consumption (i.e., number of standard drinks) from the previous day, and craving was rated at several random points each day.

RESULTS

Multilevel modeling showed that poorer average sleep quality was associated with higher levels of alcohol craving for females but not for males, and better overall levels of sleep quality were associated with decreased likelihood of engaging in alcohol use. No other person- or day-level associations between sleep and alcohol use emerged.

CONCLUSIONS

Better sleep quality may be protective against alcohol use in AYA, and female AYA who report poorer sleep quality may experience higher levels of alcohol craving. Research and clinical assessment of AYA sleep quality can contribute to understanding of factors promoting alcohol craving and use.

Too tired to drink? Daily associations of sleep duration and fatigue with own and others' alcohol consumption

OBJECTIVE

To better understand how sleep is associated with alcohol consumption among college students, the present study tested whether last night's sleep duration and current day fatigue were associated with being around others who were drinking that night and, if so, with alcohol consumption.

METHOD

College student drinkers (N = 540; mean age = 18.78 years; 52% female; 86% White) reported daily for 30 days yearly for up to 4 years on aspects of their sleep, their own alcohol use, and the perceived drinking of others in an intensive longitudinal burst design.

RESULTS

Participants were less likely to report that they were with others who were drinking on evenings following higher than average sleep duration or greater than average daytime fatigue. In addition, experiencing greater than average daytime fatigue was associated with a lower likelihood of consuming any alcohol and lower levels of alcohol consumption at the daily level. Thus, daytime fatigue may be protective against alcohol consumption through both selection and behavior moderation.

CONCLUSIONS

Results may be useful in the development of interventions to prevent heavy drinking among college students. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Association of therapeutic and recreational reasons for alcohol use with alcohol demand

Motives for alcohol use and behavioral economic measures of demand are associated with alcohol consumption and alcohol-related problems. However, it is unclear how differences in reasons for alcohol use may affect alcohol demand. Additionally, although alcohol is commonly used to self-manage conditions such as pain and sleep problems, the impact of these reasons for alcohol use on alcohol demand is not well characterized. The present study addressed this gap. Participants were adults recruited via Amazon Mechanical Turk as part of a larger study investigating health behaviors. Analyses included participants who reported alcohol use in the past year (N = 637). Participants were categorized as having recreational, therapeutic, or both recreational and therapeutic reasons for using alcohol. A brief, three-item measure of alcohol demand was administered. Multivariate analysis of variance (MANOVA) analyses revealed that alcohol drinkers endorsing both recreational and therapeutic reasons for use had significantly higher average intensity, Omax, and breakpoint indices compared to those who only reported recreational or therapeutic drinking motives (ps < .05; Cohen's d = .09-.17). Secondary analyses revealed differences in demand according to therapeutic reason for alcohol use endorsed. Significant main effects were found for use to relieve pain and anxiety/depression/stress, while interactive effects were detected for use to relieve pain and improve sleep and use to relieve pain and anxiety/depression/stress. Overall, results suggest that alcohol demand is highest in drinkers who consume alcohol for both therapeutic and recreational reasons. This group may be at elevated risk for alcohol use disorder and alcohol-related consequences. Continued research is necessary to examine this possibility. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Using Alcohol and Cannabis as Sleep Aids: Associations with Descriptive Norms Among College Students

PURPOSE

Young adults may use alcohol and cannabis as sleep aids, a risky behavior that can worsen sleep health over time and lead to substance dependence. Perceived norms for such risky behaviors are often overestimated and related to one's own use. This cross-sectional study examined: (a) the extent to which college students overestimated the prevalence of alcohol and cannabis use as sleep aids (i.e., perceived descriptive norms), and (b) the extent to which perceived descriptive norms were associated with students' own use of alcohol and cannabis as sleep aids.

METHODS

2,642 undergraduate college students (Mage = 18.84 years) reported past 30-day use of alcohol and cannabis as sleep aids. Participants also estimated the percent of college students who use alcohol and cannabis as sleep aids (i.e., perceived descriptive norms).

RESULTS

One-sample t-tests revealed participants, on average, overestimated the norms for using alcohol and cannabis as sleep aids. Participants who endorsed past 30-day use of these substances as sleep aids overestimated these norms to an even greater extent. Count regression models showed perceived descriptive norms were associated with students' use of alcohol and of cannabis as sleeps aids, in respective models, even when controlling for sleep difficulties.

CONCLUSIONS

College students may overestimate the prevalence of using alcohol and cannabis as sleep aids, and students who believe these behaviors are more normative report more frequent use of these substances as sleep aids. Taken together, findings may highlight the potential for norm-correcting strategies as a prudent approach to reducing/preventing the use of alcohol and cannabis as sleep aids.

Update on Pharmacological Treatment for Comorbid Major Depressive and Alcohol Use Disorders: The Role of Extended-release Trazodone

BACKGROUND

Major Depressive Disorder (MDD) and Alcohol Use Disorder (AUD) are major public health concerns because of their high prevalence and clinical and functional severity. MDD and AUD commonly co-occur, but effective therapeutic approaches for comorbidity are still scarce. Available evidence on selective serotonin reuptake inhibitors and tricyclic antidepressants held mixed results, and further pharmacological categories have been less investigated. Trazodone is an approved antidepressant drug for adults and has shown efficacy on symptoms like anxiety and insomnia observed in AUD patients as well. Thus, this study aims to evaluate the effect of extended-release trazodone on clinical and functional features in MDD + AUD subjects.

METHODS

One hundred MDD + AUD outpatients were retrospectively evaluated at 1, 3, and 6 months of treatment with extended-release trazodone (150-300 mg/day, flexibly dosed). Improvement in depressive symptoms was the primary outcome measure. Changes in anxiety, sleep, functioning, quality of life, clinical global severity, and alcohol craving were also investigated.

RESULTS

Trazodone reduced depressive symptoms (p < 0.001) with 54.5% remission at the endpoint. Similar improvements were observed in all secondary outcomes, including anxiety, sleep alterations, and craving (p < 0.001). Only mild side effects were reported and disappeared over time.

CONCLUSION

Extended-release trazodone displayed good antidepressant properties in MDD + AUD patients, ameliorating overall symptomatology, functioning, and quality of life, with a good safety/ tolerability profile. Further, it significantly improved sleep disturbances and craving symptoms, which are associated with drinking relapse and worse outcomes. Therefore, trazodone might represent a promising pharmacological option for MDD + AUD patients.

Daily-level associations between sleep duration and next-day alcohol and cannabis craving and use in young adults

STUDY OBJECTIVES

To examine the effects of sleep duration on next-day alcohol and cannabis craving and use among young adults.

METHOD

A community sample of young adults who reported recent simultaneous alcohol and cannabis use at screening (N = 409; Mage = 21.61; 50.9% female) completed twice daily surveys (morning and afternoon) for five 14-day sampling bursts (i.e., 70 days total). Daily measurements included sleep duration, alcohol and cannabis craving, and alcohol and cannabis use (i.e., number of drinks, hours high). Multilevel models enabled examining associations between sleep duration and substance use/craving at three distinct levels: daily-level, burst-level, and person-level.

RESULTS

At the day-level, sleep duration was inversely associated with craving for both alcohol and cannabis: Stronger craving was reported on mornings and afternoons after relatively shorter sleep duration. At the burst-level, sleep duration was inversely associated with morning and afternoon alcohol craving indicating stronger alcohol craving, but not cannabis craving, during two-week periods when young adults have accumulated shorter sleep duration. Pertaining to alcohol and cannabis use, no daily-level effects were found, but the burst-level effect showed that participants engaged in greater alcohol use during two-week bursts with shorter sleep duration.

CONCLUSIONS

Based on a non-clinical sample of young adults reporting substance use, results suggest shorter sleep duration may be a modifiable risk factor as it pertains to substance use and cravings. Results highlight day-level effects of shorter sleep duration on substance use cravings and adverse effects of cumulative sleep deficit on alcohol use.

Daily associations between modifiable sleep behaviors and nighttime sleep among young adult drinkers with insomnia

STUDY OBJECTIVES

Empirical evidence linking individual sleep hygiene practices to subsequent sleep parameters is limited, particularly at the daily level. This study compared the strength of daily, within-person associations between these modifiable sleep behaviors and nighttime sleep in young adult drinkers with insomnia.

METHODS

Young adults (ages 18-30 years; n = 56) who met diagnostic criteria for insomnia and reported past-month binge drinking wore wrist actigraphy and completed online sleep diaries for 8.5 days (standard deviation = 2.3; 477 reports). Diaries assessed engagement in 11 sleep hygiene recommendations. Multilevel models tested daily associations between sleep behaviors and 3 outcomes: sleep quality, self-reported sleep efficiency, and actigraphy-measured sleep efficiency.

RESULTS

Participants self-reported better sleep quality/efficiency on days that they slept in a comfortable environment, limited naps to 30 minutes, and maintained a consistent wake time. They self-reported worse sleep quality and efficiency on nights that they avoided alcohol use before bedtime. No sleep behaviors were significantly associated with actigraphy-measured sleep efficiency after correcting for inflation in type I error.

CONCLUSIONS

The sleep hygiene recommendations most strongly associated with sleep at the daily level were consistent with stimulus control. Creating a comfortable sleep environment also emerged as an important correlate of daily sleep. Heavy drinkers with insomnia may perceive better sleep if they drink before bedtime; however, this finding may be unique to this population.

CITATION

Miller MB, Curtis AF, Hall NA, et al. Daily associations between modifiable sleep behaviors and nighttime sleep among young adult drinkers with insomnia. J Clin Sleep Med. 2022;18(3):703-712.

Understanding the Role of Orexin Neuropeptides in Drug Addiction: Preclinical Studies and Translational Value

Orexins (also known as hypocretins) are neuropeptides that participate in the regulation of energy metabolism, homeostasis, sleep, feeding, stress responses, arousal, and reward. Particularly relevant to the scope of the present review is the involvement of the orexin system in brain mechanisms that regulate motivation, especially highly motivated behavior, arousal, and stress, making it an ideal target for studying addiction and discovering treatments. Drug abuse and misuse are thought to induce maladaptive changes in the orexin system, and these changes might promote and maintain uncontrolled drug intake and contribute to relapse. Dysfunctional changes in this neuropeptidergic system that are caused by drug use might also be responsible for alterations of feeding behavior and the sleep-wake cycle that are commonly disrupted in subjects with substance use disorder. Drug addiction has often been associated with an increase in activity of the orexin system, suggesting that orexin receptor antagonists may be a promising pharmacological treatment for substance use disorder. Substantial evidence has shown that single orexin receptor antagonists that are specific to either orexin receptor 1 or 2 can be beneficial against drug intake and relapse. Interest in the efficacy of dual orexin receptor antagonists, which were primarily developed to treat insomnia, has grown in the field of drug addiction. Treatments that target the orexin system may be a promising strategy to reduce drug intake, mitigate relapse vulnerability, and restore “normal” physiological functions, including feeding and sleep. The present review discusses preclinical and clinical evidence of the involvement of orexins in drug addiction and possible beneficial pharmacotherapeutic effects of orexin receptor antagonists to treat substance use disorder.

Cannabis and Alcohol Use and Their Associations with Sleep: A Daily Diary Investigation of Single-Use and Co-Use in College Students

Introduction: Sleep continuity problems are widespread among college students and may be influenced by single-use and co-use of alcohol and cannabis. We examined the within-person associations of alcohol and cannabis use with subsequent sleep experiences in the everyday life of college students. Materials and Methods: A sample of 80 college students reported prior-night alcohol and cannabis use and sleep experiences for 14 consecutive days. Mixed-effects models examined the within-person relationships between alcohol and cannabis use (single- and co-use) and subsequent (1) sleep-onset latency, (2) total sleep time, (3) number of awakenings, and (4) early awakenings that night. Results: Compared to no-use evenings, alcohol and cannabis, used separately or together (co-use), were associated with shorter sleep-onset latency and longer total sleep time. Students reported more nightly awakenings after alcohol-only use compared to no-use and after co-use, and they reported fewer early awakenings after no-use and co-use. Conclusions: In line with previous experimental findings, we found that alcohol and cannabis use in the everyday life of college students were associated with sleep-inducing effects, and that alcohol use was associated with disturbed sleep continuity. The results suggest that cannabis may curb alcohol's detrimental effect on the number of awakenings and may reduce the incidence of early awakenings. Yet, due to lack of control for potentially important confounders (e.g., quantity of cannabis/alcohol consumed, withdrawal) the current results may be best seen as preliminary and further research is needed before causal inferences can be reached.

Genetically predicted insomnia and lung cancer risk: a Mendelian randomization study

BACKGROUND

The relationship between insomnia and lung cancer is scanty. The Mendelian randomization approach provides the rationale for evaluating the potential causality between genetically-predicted insomnia and lung cancer risk.

METHODS

We extracted 148 insomnia-related single-nucleotide polymorphisms (SNPs) as instrumental variables (IVs) from published genome-wide association studies (GWASs). Summary data of individual-level genetic information of participants were obtained from the International Lung Cancer Consortium (ILCCO) (29,266 cases and 56,450 controls). MR analyses were performed using the inverse-variance-weighted approach, MR pleiotropy residual sum and outlier (MR-PRESSO) test, weighted median estimator, and MR-Egger regression. Sensitivity analyses were further performed using Egger intercept analysis, leave-one-out analysis, MR-PRESSO global test, and Cochran's Q test to verify the robustness of our findings.

RESULTS

The results of the MR analysis indicated an increased risk of lung cancer in insomnia patients (OR = 1.1671; 95% CI 1.0754-1.2666, p = 0.0002). The subgroup analyses showed increased risks of lung adenocarcinoma (OR = 1.1878; 95% CI 1.0594-1.3317, p = 0.0032) and squamous cell lung cancer (OR = 1.1595; 95% CI 1.0248-1.3119, p = 0.0188).

CONCLUSION

Our study indicated that insomnia is a causal risk factor in the development of lung cancer. Due to the lack of evidence on both the epidemiology and the mechanism level, more studies are needed to better elucidate the results of the study.