Cannabinoids, Endocannabinoids and Sleep

Anandamide Attenuates Neurobehavioral Deficits and EEG Irregularities in the Chronic Sleep Deprivation Rats: The Role of Oxidative Stress and Neuroinflammation

Sleep deprivation increases stress, anxiety, and depression by altering the endocannabinoid system's function. In the present study, we aimed to investigate the anti-anxiety and anti-depressant effects of the endocannabinoid anandamide (AEA) in the chronic sleep deprivation (SD) model in rats. Adult male Wistar rats (200-250 g) were randomly divided into three groups: control + vehicle (Control), chronic sleep deprivation + vehicle (SD), and chronic sleep deprivation + 20 mg/kg AEA (SD + A). The rats were kept in a sleep deprivation device for 18 h (7 to 1 a.m.) daily for 21 days. Open-field (OFT), elevated plus maze, and forced swimming tests (FST) were used to assess anxiety and depression-like behavior. As well as the cortical EEG, CB1R mRNA expression, TNF-α, IL-6, IL-4 levels, and antioxidant activity in the brain were examined following SD induction. AEA administration significantly increased the time spent (p < 0.01), the distance traveled in the central zone (p < 0.001), and the number of climbing (p < 0.05) in the OFT; it also increased the duration and number of entries into the open arms (p < 0.01 and p < 0.05 respectively), and did not reduce immobility time in the FST (p > 0.05), AEA increased CB1R mRNA expression in the anterior and medial parts of the brain (p < 0.01), and IL-4 levels (p < 0.05). AEA also reduced IL-6 and TNF-α (p < 0.05) and modulated cortical EEG. AEA induced anxiolytic-like effects but not anti-depressant effects in the SD model in rats by modulating CB1R mRNA expression, cortical EEG, and inflammatory response.

Repeated Δ-9-Tetrahydrocannabinol administration dose dependently increases stablished schedule-induced drinking

RATIONALE

Schedule-induced drinking (SID) reproduces an excessive and repetitive behavioural pattern that has led to propose this procedure as an animal model to study compulsive behaviours. Although it is known that cannabis can cause several adverse effects, in recent years there has been great interest in the medical application of cannabis derivatives for obsessive-compulsive related disorders.

OBJECTIVES

The present study investigated the effects of repeated THC administration on rates of previously acquired SID, as well as the possible alteration of its temporal distribution along inter-food intervals.

METHODS

Male Wistar rats acquired SID under a 30 min fixed-time 30-sec food delivery schedule (from 30 to 43 sessions to reach a stable level). Thereafter, 5 or 10 mg/kg daily i.p. injections of THC or vehicle were repeatedly administered for 7 days to evaluate the effects on SID.

RESULTS

Repeated THC administration at a dose of 5 mg/kg resulted in an increase on licking. Surprisingly, no effects on SID were observed with the 10 mg/kg dose. However, magazine entries were reduced with both THC doses. THC also modified the temporal distributions of licking and magazine entries during inter-food intervals.

CONCLUSIONS

The present results show that repeated THC administration may (i) increase induced licking at moderate doses, (ii) reduce magazine entries, and (iii) affect the temporal pattern of SID. These findings suggest that THC does not appear to be beneficial to reduce compulsive behaviour in this animal model, while another collateral effect of THC -such as a greater habitual-like behaviour- needs to be considered.

Endocannabinoid agonist 2-arachidonoylglycerol differentially alters diurnal activity and sleep during fentanyl withdrawal in male and female mice

Fentanyl has become the leading driver of opioid overdoses in the United States. Cessation of opioid use represents a challenge as the experience of withdrawal drives subsequent relapse. One of the most prominent withdrawal symptoms that can contribute to opioid craving and vulnerability to relapse is sleep disruption. The endocannabinoid agonist, 2-Arachidonoylglycerol (2-AG), may promote sleep and reduce withdrawal severity; however, the effects of 2-AG on sleep disruption during opioid withdrawal have yet to be assessed. Here, we investigated the effects of 2-AG administration on sleep-wake behavior and diurnal activity in mice during withdrawal from fentanyl. Sleep-wake activity measured via actigraphy was continuously recorded before and after chronic fentanyl administration in both male and female C57BL/6 J mice. Immediately following cessation of fentanyl administration, 2-AG was administered intraperitoneally to investigate the impact of endocannabinoid agonism on opioid-induced sleep disruption. We found that female mice maintained higher activity levels in response to chronic fentanyl than male mice. Furthermore, fentanyl administration increased wake and decreased sleep during the light period and inversely increased sleep and decreased wake in the dark period in both sexes. 2-AG treatment increased arousal and decreased sleep in both sexes during first 24-h of withdrawal. On withdrawal day 2, only females showed increased wakefulness with no changes in males, but by withdrawal day 3 male mice displayed decreased rapid-eye movement sleep during the dark period with no changes in female mice. Overall, repeated administration of fentanyl altered sleep and diurnal activity and administration of the endocannabinoid agonist, 2-AG, had sex-specific effects on fentanyl-induced sleep and diurnal changes.

Cannabis Science and Therapeutics: An Overview for Clinicians

Cannabis-based therapeutics have garnered increasing attention in recent years as patients seek alternative treatments for various medical conditions. This narrative review provides a comprehensive overview of the science behind the medical use of cannabis, focusing on the medical evidence for commonly treated conditions. In addition, the review addresses the practical considerations of using cannabis as a therapeutic agent, offering insights into dosing strategies, variations in cannabinoid formulation, and individual patient responses. Precautions, adverse consequences, and drug interactions are also discussed, with a focus on patient safety and the potential risks associated with cannabis use.

Stability and inter-family associations of hair endocannabinoid and N-acylethanolamines across the perinatal period in mothers, fathers, and children

Analysis of endocannabinoids (ECs) and N-acylethanolamines (NAEs) in hair is assumed to retrospectively assess long-term EC/NAE concentrations. To inform their use, this study investigated stability of EC/NAE hair concentrations in mothers, fathers, and their children across the perinatal period as well as associations between family members. In a prospective cohort study, EC (AEA, 1-AG/2-AG) and NAE (SEA, PEA, OEA) levels were quantified in hair samples taken four times in mothers (n = 336) and their partners (n = 225) from pregnancy to two years postpartum and in offspring (n = 319) from shortly after birth to two years postpartum. Across the perinatal period, maternal and paternal hair ECs/NAEs showed poor multiple-test consistency (16-36%) and variable relative stability, as well as inconsistent absolute stability for mothers. Regarding children, hair ECs/NAEs evidenced poor multiple-test consistency (4-19%), no absolute stability, and either no or variable relative stability. Hair ECs/NAEs showed small to medium significant associations across the perinatal period within couples and parent-child dyads. Findings suggest hair ECs/NAEs during the perinatal period possess variable stability in adults, albeit more stability in fathers than mothers in this time. This highlights the need to further investigate factors associated with changes in hair ECs/NAEs across time. The first two years of life may be a dynamic phase for the endocannabinoid system in children, potentially characterized by complex within-family correspondence that requires further systematic investigation.

Milk-based culture of Penicillium camemberti and its component oleamide affect cognitive function in healthy elderly Japanese individuals: a multi-arm randomized, double-blind, placebo-controlled study

Dairy products and fermented foods have a reported association with maintained cognitive function. Camembert cheese, a dairy product fermented by the white mold Penicillium camemberti, has also been shown to enhance cognitive function in vivo. Oleamide, derived from the fermentation of the white mold, is a candidate for an active component, and expected to improve both cognitive function and sleep conditions. Thus, this study investigated whether the milk-based culture of white mold (MCW), and oleamide, could improve cognitive function and sleep state clinically. A multi-arm randomized, double-blind, placebo-controlled trial was conducted in Tokyo, Japan. 60 healthy Japanese individuals aged 50-75 who were aware of their cognitive decline were randomly and equally divided into three groups of 20 participants using computer-generated random numbers. Participants took either MCW (equivalent to 60 μg/day of oleamide), 60 μg/day of oleamide, or placebo capsules for 12 weeks. Serum BDNF, cognitive function by Cognitrax as primary and MCI Screen as secondary outcome, and sleep status using the Japanese version of the Pittsburgh Sleep Quality Index (PSQI-J) were assessed before and after intervention. The participants, outcome assessors and analysts, and research assistants were blinded to the group assignment. Of the 60 participants, 58 completed the study and were analyzed. No adverse events related to test foods were observed. The placebo group showed a negative rate of change in serum BDNF (-10.5% ± 19.7%), whereas the MCW and oleamide groups showed positive changes (2.0% ± 27.1% and 1.3% ± 13.5%, respectively). Cognitrax scores increased after 12 weeks in all groups. Conversely, the MPI score of the MCI Screen demonstrated a significant improvement in the MCW and oleamide groups compared to the placebo group (p = 0.013 and p < 0.001, respectively). The subscales, immediate free recall and delayed free recall, also significantly increased in them compared to the placebo group. Although PSQI-J revealed no significant differences among groups, the MCW and oleamide groups showed significant improvement after intervention in overall score, subjective sleep quality, and sleep latency. Our results suggest that MCW and its component, oleamide, are safe and contribute to maintaining cognitive functions, particularly short-term and working memory, and improving sleep state. Clinical trial registration: https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000054792, identifier UMIN-CTR UMIN000048084.

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.

The Role of Cannabis and The Endocannabinoid System in Sleep Regulation and Cognition: A Review of Human and Animal Studies

OBJECTIVES

Both sleep and cognition are partially modulated by the endocannabinoid (ECB) system. Cannabis has been reported to have effects on sleep and cognition. This review aims to summarize the recent literature on the ECB system, the role of cannabis and the ECB system on sleep regulation and cognition. Further, this review will identify existing gaps in knowledge and suggest potential targets for future research.

METHODS

We performed this review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Reports were identified by searching PubMed/MEDLINE, Embase, CINAHL, Web of Science, and PsycINFO for articles published through September 2021 for studies with data available on aspects of cognition, cannabis, or the ECB system, and sleep or circadian rhythms (CRs).

RESULTS

We identified 6 human and 6 animal studies to be eligible for inclusion in this review. Several human studies found that cannabis use is not associated with changes in sleep quality or cognitive function. However, individual cannabinoids appeared to have independent effects on cognition and sleep; THC alone decreased cognitive performance and increased daytime sleepiness, whereas CBD alone had no effect on sleep or cognition. Animal studies demonstrated that manipulation of the ECB system altered activity and cognitive function, some of which appeared to be dependent on the light/dark cycle.

CONCLUSION

The sleep-wake cycle and CRs are both likely modulated by the ECB system, potentially resulting in effects on cognition, however this area is critically understudied.

A cohort study comparing the effects of medical cannabis for anxiety patients with and without comorbid sleep disturbance

BACKGROUND

Research on cannabis-based medicinal products (CBMPs) in anxiety remains inconclusive due to a paucity of high-quality evidence. Studies indicate a bidirectional relationship between generalized anxiety disorder (GAD) and sleep disruption, but it is unclear how this affects CBMP treatment outcomes. This study aims to compare the patient-reported outcome measures (PROMs) of patients prescribed CBMPs for GAD, with and without impaired sleep.

METHODS

Changes in PROMs were recorded from baseline to 1, 3, 6, and 12 months between those with impaired or unimpaired sleep. Multivariate logistic regression was applied to compare factors associated with a clinically significant improvement in GAD-7 at 12 months. Secondary outcomes included adverse event incidence and frequency.

RESULTS

Of the 302 patients that fit the inclusion criteria, mean GAD-7, single-item sleep quality, and EQ-5D-5L index values improved at all time points (p < 0.001). A relationship between sleep impairment and clinically significant changes in GAD-7 at 1 and 3 months was identified (p ≤ 0.01). On multivariate regression, only baseline GAD severity was associated with an increased likelihood of observing a clinically significant improvement in anxiety (p < 0.001). Seven hundred and seven (234%) adverse events were reported by 55 (18.21%) participants.

CONCLUSIONS

This study observed an association between CBMP treatment and improvements in anxiety in patients with GAD. While patients with comorbid sleep disruption had greater improvements in anxiety, the differences were not maintained in a multivariate analysis. Baseline anxiety severity may be a predictor for CBMP treatment outcomes.

Evaluating Fatty Acid Amide Hydrolase as a Suitable Target for Sleep Promotion in a Transgenic TauP301S Mouse Model of Neurodegeneration

Sleep disruption is an expected component of aging and neurodegenerative conditions, including Alzheimer's disease (AD). Sleep disruption has been demonstrated as a driver of AD pathology and cognitive decline. Therefore, treatments designed to maintain sleep may be effective in slowing or halting AD progression. However, commonly used sleep aid medications are associated with an increased risk of AD, highlighting the need for sleep aids with novel mechanisms of action. The endocannabinoid system holds promise as a potentially effective and novel sleep-enhancing target. By using pharmacology and genetic knockout strategies, we evaluated fatty acid amide hydrolase (FAAH) as a therapeutic target to improve sleep and halt disease progression in a transgenic Tau P301S (PS19) model of Tauopathy and AD. We have recently shown that PS19 mice exhibit sleep disruption in the form of dark phase hyperarousal as an early symptom that precedes robust Tau pathology and cognitive decline. Acute FAAH inhibition with PF3845 resulted in immediate improvements in sleep behaviors in male and female PS19 mice, supporting FAAH as a potentially suitable sleep-promoting target. Moreover, sustained drug dosing for 5-10 days resulted in maintained improvements in sleep. To evaluate the effect of chronic FAAH inhibition as a possible therapeutic strategy, we generated FAAH-/- PS19 mice models. Counter to our expectations, FAAH knockout did not protect PS19 mice from progressive sleep loss, neuroinflammation, or cognitive decline. Our results provide support for FAAH as a novel target for sleep-promoting therapies but further indicate that the complete loss of FAAH activity may be detrimental.

Role of Cannabinoids in Oral Cancer

Cannabinoids have incited scientific interest in different conditions, including malignancy, due to increased exposure to cannabis. Furthermore, cannabinoids are increasingly used to alleviate cancer-related symptoms. This review paper aims to clarify the recent findings on the relationship between cannabinoids and oral cancer, focusing on the molecular mechanisms that could link cannabinoids with oral cancer pathogenesis. In addition, we provide an overview of the current and future perspectives on the management of oral cancer patients using cannabinoid compounds. Epidemiological data on cannabis use and oral cancer development are conflicting. However, in vitro studies assessing the effects of cannabinoids on oral cancer cells have unveiled promising anti-cancer features, including apoptosis and inhibition of cell proliferation. Downregulation of various signaling pathways with anti-cancer effects has been identified in experimental models of oral cancer cells exposed to cannabinoids. Furthermore, in some countries, several synthetic or phytocannabinoids have been approved as medical adjuvants for the management of cancer patients undergoing chemoradiotherapy. Cannabinoids may improve overall well-being by relieving anxiety, depression, pain, and nausea. In conclusion, the link between cannabinoid compounds and oral cancer is complex, and further research is necessary to elucidate the potential risks or their protective impact on oral cancer.

Sex-specific Effects of the Endocannabinoid Agonist 2-Arachidonoylglycerol on Sleep and Circadian Disruptions during Fentanyl Withdrawal

Fentanyl has become the leading driver of opioid overdoses. Cessation of opioid use represents a challenge as the experience of withdrawal drives subsequent relapse. One of the most prominent withdrawal symptoms that can contribute to opioid craving and vulnerability to relapse is sleep disruption. The endocannabinoid agonist, 2-Arachidonoylglycerol (2-AG), may promote sleep and reduce withdrawal severity; however, the effects of 2-AG on sleep disruption during opioid withdrawal have yet to be assessed. Here, we investigate the effects of 2-AG administration on sleep-wake behavior and diurnal activity in mice during withdrawal from fentanyl. Sleep-wake activity was continuously recorded before and after chronic fentanyl administration in both male and female C57BL/6J mice. Immediately following cessation of fentanyl administration, 2-AG was administered intraperitoneally to investigate the impact of endocannabinoid agonism on opioid-induced sleep disruption. Female mice maintained higher activity levels in response to chronic fentanyl than male mice. Furthermore, fentanyl increased wake and decreased sleep during the light period and inversely increased sleep and decreased wake in the dark period in both sexes. 2-AG treatment increased arousal and decreased sleep in both sexes during first 24 hrs of withdrawal. On withdrawal day 2, only female showed increased wakefulness with no changes in males, but by withdrawal day 3 male mice displayed decreased rapid-eye movement sleep during the dark period with no changes in female mice. Overall, repeated administration of fentanyl altered sleep and diurnal activity and administration of the endocannabinoid agonist, 2-AG, had sex-specific effects on fentanyl-induced sleep and diurnal changes.

UK Medical Cannabis Registry: An analysis of clinical outcomes of medicinal cannabis therapy for attention-deficit/hyperactivity disorder

AIM

This study aims to analyze the health-related quality of life (HRQoL) and safety outcomes in attention-deficit/hyperactivity disorder (ADHD) patients treated with cannabis-based medicinal products (CBMPs).

METHODS

Patients were identified from the UK Medical Cannabis Registry. Primary outcomes were changes in the following patient-reported outcome measures (PROMs) at 1, 3, 6, and 12 months from baseline: EQ-5D-5L index value, generalized anxiety disorder-7 (GAD-7) questionnaire, and the single-item sleep quality score (SQS). Secondary outcomes assessed the incidence of adverse events. Statistical significance was defined as p < 0.050.

RESULTS

Sixty-eight patients met the inclusion criteria. Significant improvements were identified in general HRQoL assessed by EQ-5D-5L index value at 1, 3, and 6 months (p < 0.050). Improvements were also identified in GAD-7 and SQS scores at 1, 3, 6, and 12 months (p < 0.010). 61 (89.71%) adverse events were recorded by 11 (16.18%) participants, of which most were moderate (n = 26, 38.24%).

CONCLUSION

An association between CBMP treatment and improvements in anxiety, sleep quality, and general HRQoL was observed in patients with ADHD. Treatment was well tolerated at 12 months. Results must be interpreted with caution as a causative effect cannot be proven. These results, however, do provide additional support for future evaluation within randomized controlled trials.

Dose-dependent Relationships of Same-day and Typical Substance Use to Sleep Duration in College Cannabis and Alcohol Users: A Multilevel Modeling Approach Using Daily Diary Data

This study characterized how quantities of cannabis and alcohol use affect sleep. Single-day and typical cannabis and alcohol use patterns were considered to assess acute-chronic use interactions. Linear and non-linear associations assessed dose-dependence. College students (n=337; 52% female) provided 11,417 days of data, with up to five time points per day. Daily self-reported sleep duration, cannabis use quantity, and alcohol use quantity were subjected to linear mixed modeling to capture linear and curvilinear associations between single-day and typical use on same-night and typical sleep. Sleep duration (difference between bedtime and waketime) was the outcome. Quantity of cannabis used each day andtypical quantity used across all days were predictors in the cannabis models. Parallel single-day and typical alcohol variables were predictors in the alcohol models. Follow-up analyses excluded days with alcohol-cannabis co-use. Main effects of single-day and typical cannabis quantity on sleep duration were observed when all cannabis-use days were modeled. Higher than typical doses of single-day and typical cannabis were associated with longer sleep durations, but only to a point; at the highest doses, cannabis shortened sleep. A main effect of single-day alcohol quantity and two interactions (single-day use with both linear and curvilinear typical use) on sleep duration were observed when all alcohol-use days were modeled. Greater alcohol consumption on a given day led to shorter same-night sleep, but typically heavier drinkers required higher doses than typically lighter drinkers to experience these adverse effects. Follow-up models suggested alcohol co-use may contribute to the purported sleep-promoting effects of cannabis.

Assessing changes in sleep across four weeks among adolescents randomized to incentivized cannabis abstinence

BACKGROUND

Withdrawal from cannabis use is associated with sleep disturbances, often leading to resumption of use. Less is known about the impact of abstinence on sleep in adolescence, a developmental window associated with high rates of sleep disturbance. This study investigated effects of sustained abstinence on self-reported sleep quality and disturbance in adolescents reporting frequent cannabis use.

METHODS

Non-treatment seeking adolescents, recruited from school screening surveys and the community, with frequent cannabis use (MAge=17.8, SDAge=1.7, 47% female, 45% non-white) were randomized to four weeks of biochemically-verified abstinence, motivated via contingency management (CB-Abst, n=53), or monitoring without an abstinence requirement (CB-Mon, n=63). A mixed-effects model was used to predict change in Pittsburgh Sleep Quality Index (PSQI) scores.

RESULTS

Participants in CB-Abst reported higher overall PSQI scores than those in CB-Mon (M=1.06, p=0.01) indicating worse sleep during the four-week trial. Sleep disruptions in CB-Abst increased during Week 1 of abstinence (d=0.34, p=0.04), decreased during Week 2 (d=0.36, p=0.04), and remained constant for the rest of the trial. At Week 4, sleep was comparable to baseline levels for those in CB-Abst (p=0.87). Withdrawal-associated sleep disruption in the CB-Abst group was circumscribed to increases in sleep latency (b=0.35; p=0.05).

CONCLUSIONS

Cannabis abstinence in adolescents was associated with transient delayed onset of sleep initiation falling asleep during the first week of abstinence. Findings highlight withdrawal-associated changes in sleep latency as an intervention target for supporting adolescents attempting abstinence. Future research should use objective measures of sleep and focus on elucidating mechanisms underlying sleep disturbances with cannabis use and withdrawal.

A cross-sectional survey of the prevalence and patterns of using cannabis as a sleep aid in Canadian cancer survivors

PURPOSE

Poor sleep is one of the most common side effects of cancer. It can persist for years beyond treatment and negatively impact quality of life and health. Cannabis is increasingly used to manage cancer treatment-related symptoms, including sleep. This study investigated the use and perceived effects of cannabis as a sleep aid in Canadian cancer survivors.

METHODS

Adult Canadian cancer survivors (N = 1464) were recruited via the Angus Reid Institute and completed an online, cross-sectional survey including the Insomnia Severity Index and questions about cannabis use for sleep. Standard descriptive statistics, such as means, standard deviations, and ranges were produced for measured variables to assess the ways cancer survivors use cannabis for sleep. Frequencies were tabulated for categorical and ordinal variables.

RESULTS

On average, participants (Mage = 61.1 years; Women = 50%: Men = 48%) received their cancer diagnosis 12.5 years prior. Of participants, 23.5% (n = 344) currently use cannabis as a sleep aid, with reported benefits including relaxation, reduced time to fall asleep, fewer nocturnal awakenings and improved sleep quality. Two thirds (68.3%, n = 235) only began using cannabis for sleep after their cancer diagnosis. Over a third of participants (36.3%, n = 125) use cannabis as a sleep aid every day. Among the 344, the most common other reasons for using cannabis were pain (31.4%, n = 108), recreational use (24.4%, n = 84), and anxiety (12.5%, n = 43).

CONCLUSIONS

Given the prevalence and potential impact, research is needed to examine the actual efficacy of cannabis as a sleep aid.

IMPLICATIONS FOR CANCER SURVIVORS

It is important that cancer survivors have information on methods to help their sleep to avoid impairments to quality of life and health.

Cannabis use and sleep disturbances among White, Black, and Latino adults in the United States: A cross-sectional study of National Comorbidity Survey-Replication (2001-2003) data

OBJECTIVE

Research investigating cannabis use and sleep health is limited, and results are mixed. Few studies were nationally representative with racially-ethnically diverse samples or assessed potential modifiers. Our objective was to investigate cross-sectional associations between reported cannabis use and sleep disturbances by potential modifiers among non-Hispanic White, non-Hispanic Black, and Hispanic/Latino men and women in the United States.

METHODS

We used nationally representative National Comorbidity Survey-Replication data collected from 2001 to 2003 among 3929 adults. Poisson regression with robust variance estimated prevalence ratios (PR) and 95% confidence intervals of patterns of sleep disturbances identified through latent class analysis. Models adjusted for sociodemographic, health behavior, and clinical characteristics were stratified by race-ethnicity and by race-ethnicity along with sex/gender, and age, separately.

RESULTS

Over half of adults reported cannabis use (52%-ever/lifetime vs 48%-never). We identified two latent classes: multiple sleep disturbances with daytime sleepiness and no sleep disturbances with some daytime sleepiness. Prevalence of multiple sleep disturbances with daytime sleepiness was higher among participants reporting lifetime cannabis use (23% vs 20%). Associations did not vary by race-ethnicity or sex/gender. Lifetime vs never cannabis use was marginally associated with a higher prevalence of multiple sleep disturbances with daytime sleepiness only among adults aged 25-29years (PR=1.09 [95% confidence interval: 1.00-1.18]; eg, PRage 40+ years=1.00 [0.97-1.03], pinteraction=0.03).

CONCLUSIONS

Associations between cannabis use and sleep may vary by age. Replication with more recent data and prospective studies that investigate intersectional identities among diverse populations with objective assessments are warranted.

Pharmacological interventions targeting α-synuclein aggregation triggered REM sleep behavior disorder and early development of Parkinson's disease

Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by elevated motor behaviors and dream enactments in REM sleep, often preceding the diagnosis of Parkinson's disease (PD). As RBD could serve as a biomarker for early PD developments, pharmacological interventions targeting α-synuclein aggregation triggered RBD could be applied toward early PD progression. However, robust therapeutic guidelines toward PD-induced RBD are lacking, owing in part to a historical paucity of effective treatments and trials. We reviewed the bidirectional links between α-synuclein neurodegeneration, progressive sleep disorders, and RBD. We highlighted the correlation between RBD development, α-synuclein aggregation, and neuronal apoptosis in key brainstem regions involved in REM sleep atonia maintenance. The current pharmacological intervention strategies targeting RBD and their effects on progressive PD are discussed, as well as current treatments for progressive neurodegeneration and their effects on RBD. We also evaluated emerging and potential pharmacological solutions to sleep disorders and developing synucleinopathies. This review provides insights into the mechanisms and therapeutic targets underlying RBD and PD, and explores bidirectional treatment effects for both diseases, underscoring the need for further research in this area.

Tetrahydrocannabinols: potential cannabimimetic agents for cancer therapy

Tetrahydrocannabinols (THCs) antagonize the CB1 and CB2 cannabinoid receptors, whose signaling to the endocannabinoid system is essential for controlling cell survival and proliferation as well as psychoactive effects. Most tumor cells express a much higher level of CB1 and CB2; THCs have been investigated as potential cancer therapeutic due to their cannabimimetic properties. To date, THCs have been prescribed as palliative medicine to cancer patients but not as an anticancer modality. Growing evidence of preclinical research demonstrates that THCs reduce tumor progression by stimulating apoptosis and autophagy and inhibiting two significant hallmarks of cancer pathogenesis: metastasis and angiogenesis. However, the degree of their anticancer effects depends on the origin of the tumor site, the expression of cannabinoid receptors on tumor cells, and the dosages and types of THC. This review summarizes the current state of knowledge on the molecular processes that THCs target for their anticancer effects. It also emphasizes the substantial knowledge gaps that should be of concern in future studies. We also discuss the therapeutic effects of THCs and the problems that will need to be addressed in the future. Clarifying unanswered queries is a prerequisite to translating the THCs into an effective anticancer regime.

Cannabinol (CBN; 30 and 300 mg) effects on sleep and next-day function in insomnia disorder ('CUPID' study): protocol for a randomised, double-blind, placebo-controlled, cross-over, three-arm, proof-of-concept trial

OBJECTIVE

Insomnia is the most prevalent sleep disorder, with few effective pharmacotherapies. Anecdotal reports and recent preclinical research suggest that cannabinol (CBN), a constituent of Cannabis sativa derived from delta-9-tetrahydrocannabinol, could be an effective treatment. Despite this, the isolated effects of CBN on sleep have yet to be systematically studied in humans.

METHODS

The present protocol paper describes a randomised, double-blind, placebo-controlled, single-dose, three-arm, cross-over, proof-of-concept study which investigates the effects of CBN on sleep and next-day function in 20 participants with clinician-diagnosed insomnia disorder and an Insomnia Severity Index Score ≥15. Participants receive a single fixed oral liquid dose of 30 mg CBN, 300 mg CBN and matched placebo, in random order on three treatment nights; each separated by a 2-week wash-out period. Participants undergo overnight sleep assessment using in-laboratory polysomnography and next-day neurobehavioural function tests. The primary outcome is wake after sleep onset minutes. Secondary outcomes include changes to traditional sleep staging, sleep-onset latency and absolute spectral power during non-rapid eye movement (NREM) sleep. Tertiary outcomes include changes to sleep spindles during NREM sleep, arousal indices, absolute spectral power during REM sleep and subjective sleep quality. Safety-related and exploratory outcomes include changes to next-day simulated driving performance, subjective mood and drug effects, postural sway, alertness and reaction time, overnight memory consolidation, pre and post-sleep subjective and objective sleepiness; and plasma, urinary, and salivary cannabinoid concentrations. The study will provide novel preliminary data on CBN efficacy and safety in insomnia disorder, which will inform larger clinical trials.

ETHICS AND DISSEMINATION

Human Research Ethics Committee approval has been granted by Bellberry (2021-08-907). Study findings will be disseminated in a peer-reviewed journal and at academic conferences.

TRIAL REGISTRATION NUMBER

NCT05344170.

Endocannabinoid basis of personality-Insights from animal model of social behavior

Rationale: The endocannabinoid system is known to be involved in learning, memory, emotional processing and regulation of personality patterns. Here we assessed the endocannabinoid profile in the brains of mice with strong characteristics of social dominance and submissiveness. Methods: A lipidomics approach was employed to assess the endocannabinoidome in the brains of Dominant (Dom) and Submissive (Sub) mice. The endocannabinoid showing the greatest difference in concentration in the brain between the groups, docosatetraenoyl ethanolamine (DEA), was synthesized, and its effects on the physiological and behavioral responses of Dom and Sub mice were evaluated. mRNA expression of the endocannabinoid receptors and enzymes involved in PUFA biosynthesis was assessed using qRT-PCR. Results: Targeted LC/MS analysis revealed that long-chain polyunsaturated ethanolamides including arachidonoyl ethanolamide (AEA), DEA, docosatrienoyl ethanolamide (DTEA), eicosatrienoyl ethanolamide (ETEA), eicosapentaenoyl ethanolamide (EPEA) and docosahexaenoyl ethanolamide (DHEA) were higher in the Sub compared with the Dom mice. Untargeted LC/MS analysis showed that the parent fatty acids, docosatetraenoic (DA) and eicosapentaenoic (EPA), were higher in Sub vs. Dom. Gene expression analysis revealed increased mRNA expression of genes encoding the desaturase FADS2 and the elongase ELOVL5 in Sub mice compared with Dom mice. Acute DEA administration at the dose of 15 mg/kg produced antinociceptive and locomotion-inducing effects in Sub mice, but not in Dom mice. Subchronic treatment with DEA at the dose of 5 mg/kg augmented dominant behavior in wild-type ICR and Dom mice but not in Sub mice. Conclusion: This study suggests that the endocannabinoid system may play a role in the regulation of dominance and submissiveness, functional elements of social behavior and personality. While currently we have only scratched the surface, understanding the role of the endocannabinoid system in personality may help in revealing the mechanisms underlying the etiopathology of psychiatric disorders.

Mechanisms of cannabinoid tolerance

Cannabis has been used recreationally and medically for centuries, yet research into understanding the mechanisms of its therapeutic effects has only recently garnered more attention. There is evidence to support the use of cannabinoids for the treatment of chronic pain, muscle spasticity, nausea and vomiting due to chemotherapy, improving weight gain in HIV-related cachexia, emesis, sleep disorders, managing symptoms in Tourette syndrome, and patient-reported muscle spasticity from multiple sclerosis. However, tolerance and the risk for cannabis use disorder are two significant disadvantages for cannabinoid-based therapies in humans. Recent work has revealed prominent sex differences in the acute response and tolerance to cannabinoids in both humans and animal models. This review will discuss evidence demonstrating cannabinoid tolerance in rodents, non-human primates, and humans and our current understanding of the neuroadaptations occurring at the cannabinoid type 1 receptor (CB1R) that are responsible tolerance. CB1R expression is downregulated in tolerant animals and humans while there is strong evidence of CB1R desensitization in cannabinoid tolerant rodent models. Throughout the review, critical knowledge gaps are indicated and discussed, such as the lack of a neuroimaging probe to assess CB1R desensitization in humans. The review discusses the intracellular signaling pathways that are responsible for mediating CB1R desensitization and downregulation including the action of G protein-coupled receptor kinases, β-arrestin2 recruitment, c-Jun N-terminal kinases, protein kinase A, and the intracellular trafficking of CB1R. Finally, the review discusses approaches to reduce cannabinoid tolerance in humans based on our current understanding of the neuroadaptations and mechanisms responsible for this process.

Cannabis use for Sleep Disturbance Among Older Patients in a Geriatrics Clinic

Cannabis use is growing among older adults to manage medical concerns including poor sleep. In this study, we characterized how patients seen at a geriatrics clinic use cannabis to address sleep disturbance. Specifically, we conducted an anonymous survey of 568 adults, including 83 who reported cannabis use within the past 3 years, to inquire about such use. We compared cannabis use characteristics between those using it for sleep disturbance versus all other conditions. We considered a p-value <.10 to be statistically significant. Among the cannabis users in our sample, 29% reported using cannabis for sleep disturbance (N = 24). They were more likely than other users to be female (p = .07), consume cannabis more frequently (p = .01), use products containing tetrahydrocannabinol (THC) (vs. cannabidiol [CBD]-only; p < .01), and use cannabis to target more symptoms (p < .01). As cannabis use continues to grow in older populations, it is essential to delineate better how cannabis may be used safely and effectively to improve older adults' sleep health.

Role of astrocytes in sleep deprivation: accomplices, resisters, or bystanders?

Sleep plays an essential role in all studied animals with a nervous system. However, sleep deprivation leads to various pathological changes and neurobehavioral problems. Astrocytes are the most abundant cells in the brain and are involved in various important functions, including neurotransmitter and ion homeostasis, synaptic and neuronal modulation, and blood-brain barrier maintenance; furthermore, they are associated with numerous neurodegenerative diseases, pain, and mood disorders. Moreover, astrocytes are increasingly being recognized as vital contributors to the regulation of sleep-wake cycles, both locally and in specific neural circuits. In this review, we begin by describing the role of astrocytes in regulating sleep and circadian rhythms, focusing on: (i) neuronal activity; (ii) metabolism; (iii) the glymphatic system; (iv) neuroinflammation; and (v) astrocyte-microglia cross-talk. Moreover, we review the role of astrocytes in sleep deprivation comorbidities and sleep deprivation-related brain disorders. Finally, we discuss potential interventions targeting astrocytes to prevent or treat sleep deprivation-related brain disorders. Pursuing these questions would pave the way for a deeper understanding of the cellular and neural mechanisms underlying sleep deprivation-comorbid brain disorders.

Cannabidiol as a candidate pharmacotherapy for sleep disturbance in alcohol use disorder

Among individuals with alcohol use disorder (AUD), it is estimated that the majority suffer from persistent sleep disturbances for which few candidate medications are available. Our aim wass to critically review the potential for cannabidiol (CBD) as a treatment for AUD-induced sleep disturbance. As context, notable side effects and abuse liability for existing medications for AUD-induced sleep disturbance reduce their clinical utility. CBD modulation of the endocannabinoid system and favorable safety profile have generated substantial interest in its potential therapeutic use for various medical conditions. A number of preclinical and clinical studies suggest promise for CBD in restoring the normal sleep-wake cycle and in enhancing sleep quality in patients diagnosed with AUD. Based on its pharmacology and the existing literature, albeit primarily preclinical and indirect, CBD is a credible candidate to address alcohol-induced sleep disturbance. Well-designed RCTs will be necessary to test its potential in managing this challenging feature of AUD.

Study of the association between cannabis use and sleep disturbances in a large sample of University students

Sleep complaints and cannabis use are common among University students and are related to detrimental effects on health. The aim of this study was to explore their association. This cross-sectional study based on the i-Share e-cohort included French students between 18 and 30 years old (n = 14,787). Frequency of cannabis use was categorized into daily, weekly, monthly, and never/rarely use. Sleep complaints were defined using four items (i.e., insomnia, sleepiness, poor sleep quality, and sleep deprivation). In the whole sample (mean age: 20.4 years, 75.5% of females), 22.7% had insomnia, 18.3% had sleepiness, 22.4% had poor sleep quality, 52.5% had sleep deprivation, and 5.8% used cannabis weekly or daily. After adjustment, the likelihood of insomnia was significantly higher by 45% in cannabis users compared to non-users. The estimates steadily increased with frequency of use, reaching a 2.0-fold higher likelihood of insomnia in daily users compared to never/rarely users. Results were similar for the other sleep complaints. These findings provide support for an association between cannabis use and sleep complaints, particularly insomnia, among University students. Though direction and causality cannot be established in this setting, these results suggest warning students and health professionals about the association between cannabis use and sleep complaints.

The beneficial effect of sleep on behavioral health problems in youth is disrupted by prenatal cannabis exposure: A causal random forest analysis of Adolescent Brain Cognitive Development data

Studies suggest prenatal cannabis exposure is associated with mood/behavioral problems in children. However, it is unclear if targeting modifiable domains like sleep behaviors would improve outcomes in exposed youth. Using a causal inference framework, the effect of changing sleep-hours on changing internalizing/externalizing problems in children was examined using the Adolescent Brain Cognitive Development™ study baseline (ages 9-10; collected during 2016-2018) and year-1 follow-up data (N = 9825; 4663 female; 5196 white). Average treatment effects (ATE) indicated that more sleep predicted less internalizing (ATE = -.34, SE = .08, p < .001) and externalizing (ATE = -.29, SE = .07, p < .001) problems over time. However, prenatal cannabis exposure moderated the ATE on internalizing (conditional-ATE = .91, SE = .39, p = .019), whereby participants with exposure (n = 605) did not show any effect of changing sleep-hours on mood (B = .09, SE = .24).

Molecular and cellular mechanisms underlying brain region-specific endocannabinoid system modulation by estradiol across the rodent estrus cycle

Neurological crosstalk between the endocannabinoid and estrogen systems has been a growing topic of discussion over the last decade. Although the main estrogenic ligand, estradiol (E2), influences endocannabinoid signaling in both male and female animals, the latter experiences significant and rhythmic fluctuations in E2 as well as other sex hormones. This is referred to as the menstrual cycle in women and the estrus cycle in rodents such as mice and rats. Consisting of 4 distinct hormone-driven phases, the rodent estrus cycle modulates both endocannabinoid and exogenous cannabinoid signaling resulting in unique behavioral outcomes based on the cycle phase. For example, cannabinoid receptor agonist-induced antinociception is greatest during proestrus and estrus, when circulating and brain levels of E2 are high, as compared to metestrus and diestrus when E2 concentrations are low. Pain processing occurs throughout the cerebral cortex and amygdala of the forebrain; periaqueductal grey of the midbrain; and medulla and spine of the hindbrain. As a result, past molecular investigations on these endocannabinoid-estrogen system interactions have focused on these specific brain regions. Here, we will bridge regional molecular trends with neurophysiological evidence of how plasma membrane estrogen receptor (ER) activation by E2 leads to postsynaptic endocannabinoid synthesis, retrograde signaling, and alterations in inhibitory neurotransmission. These signaling pathways depend on ER heterodimers, current knowledge of which will also be detailed in this review. Overall, the aim of this review article is to systematically summarize how the cannabinoid receptors and endocannabinoids change in expression and function in specific brain regions throughout the estrus cycle.

Neuro-Gastro-Cannabinology: A Novel Paradigm for Regulating Mood and Digestive Health

The maintenance of homeostasis in the gastrointestinal (GI) tract is ensured by the presence of the endocannabinoid system (ECS), which regulates important physiological activities, such as motility, permeability, fluid secretion, immunity, and visceral pain sensation. Beside its direct effects on the GI system, the ECS in the central nervous system indirectly regulates GI functions, such as food intake and energy balance. Mounting evidence suggests that the ECS may play an important role in modulating central neurotransmission which affects GI functioning. It has also been found that the interaction between the ECS and microbiota affects brain and gut activity in a bidirectional manner, and a number of studies demonstrate that there is a strong relationship between GI dysfunctions and mood disorders. Thus, microbiota can regulate the tone of the ECS. Conversely, changes in intestinal ECS tone may influence microbiota composition. In this mini-review, we propose the concept of neuro-gastro-cannabinology as a novel and alternative paradigm for studying and treating GI disorders that affect mood, as well as mood disorders that imbalance GI physiology. This concept suggests the use of prebiotics or probiotics for improving the tone of the ECS, as well as the use of phytocannabinoids or endocannabinoid-like molecules, such as palmitoylethanolamide, to restore the normal intestinal microbiota. This approach may be effective in ameliorating the negative effects of GI dysfunctions on mood and/or the effects of mood disorders on digestive health.

Endocannabinoids at the synapse and beyond: implications for neuropsychiatric disease pathophysiology and treatment

Endocannabinoids (eCBs) are lipid neuromodulators that suppress neurotransmitter release, reduce postsynaptic excitability, activate astrocyte signaling, and control cellular respiration. Here, we describe canonical and emerging eCB signaling modes and aim to link adaptations in these signaling systems to pathological states. Adaptations in eCB signaling systems have been identified in a variety of biobehavioral and physiological process relevant to neuropsychiatric disease states including stress-related disorders, epilepsy, developmental disorders, obesity, and substance use disorders. These insights have enhanced our understanding of the pathophysiology of neurological and psychiatric disorders and are contributing to the ongoing development of eCB-targeting therapeutics. We suggest future studies aimed at illuminating how adaptations in canonical as well as emerging cellular and synaptic modes of eCB signaling contribute to disease pathophysiology or resilience could further advance these novel treatment approaches.

Machine learning prediction of posttraumatic stress disorder trajectories following traumatic injury: Identification and validation in two independent samples

Due to its heterogeneity, the prediction of posttraumatic stress disorder (PTSD) development after traumtic injury is difficult. Recent machine learning approaches have yielded insight into predicting PTSD symptom trajectories. Using data collected within 1 month of traumatic injury, we applied eXtreme Gradient Boosting (XGB) to classify admitted and discharged patients (hospitalized, n = 192; nonhospitalized, n = 214), recruited from a Level 1 trauma center, according to PTSD symptom trajectories. Trajectories were identified using latent class mixed models on PCL-5 scores collected at baseline, 1-3 months posttrauma, and 6 months posttrauma. In both samples, nonremitting, remitting, and resilient PTSD symptom trajectories were identified. In the admitted patient sample, a unique delayed trajectory emerged. Machine learning classifiers (i.e., XGB) were developed and tested on the admitted patient sample and externally validated on the discharged sample with biological and clinical self-report baseline variables as predictors. For external validation sets, prediction was fair for nonremitting versus other trajectories, areas under the curve (AUC = .70); good for nonremitting versus resilient trajectories, AUCs = .73-.76; and prediction failed for nonremitting versus remitting trajectories, AUCs = .46-.48. However, poor precision (< .57) across all models suggests limited generalizability of nonremitting symptom trajectory prediction from admitted to discharged patient samples. Consistency in symptom trajectory identification across samples supports prior studies on the stability of PTSD symptom trajectories following trauma exposure; however, continued work and replication with larger samples are warranted to understand overlapping and unique predictive features of PTSD in different traumatic injury populations.

Coordinated Regulation of CB1 Cannabinoid Receptors and Anandamide Metabolism Stabilizes Network Activity during Homeostatic Downscaling

Neurons express overlapping homeostatic mechanisms to regulate synaptic function and network properties in response to perturbations of neuronal activity. Endocannabinoids (eCBs) are bioactive lipids synthesized in the postsynaptic compartments to regulate synaptic transmission, plasticity, and neuronal excitability primarily through retrograde activation of presynaptic cannabinoid receptor type 1 (CB1). The eCB system is well situated to regulate neuronal network properties and coordinate presynaptic and postsynaptic activity. However, the role of the eCB system in homeostatic adaptations to neuronal hyperactivity is unknown. To address this issue, we used Western blotting and targeted lipidomics to measure adaptations in eCB system to bicuculline (BCC)-induced chronic hyperexcitation in mature cultured rat cortical neurons, and used multielectrode array (MEA) recording and live-cell imaging of glutamate dynamics to test the effects of pharmacological manipulations of eCB on network activities. We show that BCC-induced chronic hyperexcitation triggers homeostatic downscaling and a coordinated adaptation to enhance tonic eCB signaling. Hyperexcitation triggers first the downregulation of fatty acid amide hydrolase (FAAH), the lipase that degrades the eCB anandamide, then an accumulation of anandamide and related metabolites, and finally a delayed upregulation of surface and total CB1. Additionally, we show that BCC-induced downregulation of surface AMPA-type glutamate receptors (AMPARs) and upregulation of CB1 occur through independent mechanisms. Finally, we show that endocannabinoids support baseline network activities before and after downscaling and is engaged to suppress network activity during adaptation to hyperexcitation. We discuss the implications of our findings in the context of downscaling and homeostatic regulation of in vitro oscillatory network activities.

Plasma and interstitial levels of endocannabinoids and N-acylethanolamines in patients with chronic widespread pain and fibromyalgia: a systematic review and meta-analysis

The endocannabinoid system (ECS) is an essential endogenous signaling system that may be involved in the pathophysiology of chronic widespread pain (CWP) and fibromyalgia syndrome (FMS). Further research is required to understand the role of ECS in the development and maintenance of CWP and FMS. We provided the first systematic review and meta-analysis exploring the clinical relevance of ECS alterations in patients with CWP and FMS by comparing plasma and interstitial levels of endocannabinoids and N-acylethanolamines in patients and healthy controls. A systematic search was conducted to identify studies that measured plasma and/or interstitial levels of endocannabinoids and N-acylethanolamines in patients with CWP or FMS and healthy controls. A total of 8 studies were included for qualitative review, and 7 studies were included for meta-analysis. The findings identified increased plasma levels of oleoylethanolamide and stearoylethanolamide in patients with FMS compared with those in controls (P = 0.005 and P < 0.0001, respectively) and increased plasma levels of palmitoylethanolamide and interstitial levels of stearoylethanolamide in patients with CWP compared with those in controls (P = 0.05 and P = 0.001, respectively). There were no significant differences in other ECS parameters. Most studies did not account for variables that may influence ECS function, including cannabis use, concomitant medication, comorbidities, physical activity, stress levels, circadian rhythm, sleep quality, and dietary factors, suggesting that future studies should explore the correlation between these variables and endocannabinoid activity. We highlight the importance of investigating endocannabinoid activity in CWP and FMS because it will underpin future translational research in the area.

Cannabis use disorder severity and sleep quality among undergraduates attending a Historically Black University

Nearly one third of Americans experience poor sleep, which is associated with numerous deleterious health outcomes. Poor sleep may be exacerbated when an individual attends college, as they experience drastic shifts in lifestyle and sleep patterns. Previous research suggests cannabis has therapeutic potential for sleep disorders but may also impair sleep quality long-term. However, no study has examined the differences in sleep quality within individuals who meet criteria for Cannabis Use Disorder (CUD). The purpose of the current study was to determine differences in sleep quality among undergraduate students who met criteria for mild CUD (n = 18), moderate CUD (n = 22), severe CUD (n = 16) and students who did not meet criteria for CUD (n = 244). Participants included 300 predominantly Black/African American undergraduate students (79% female), aged between 18 and 25 years. Each participant completed an online survey that included measures assessing sleep quality and CUD criteria. Employing analysis of covariance, the moderate CUD subgroup (M = 9.00, SD = 3.32) reported poorer sleep quality than individuals who did not meet criteria for CUD (M = 6.93, SD = 3.03). Interestingly, the severe CUD subgroup (M = 6.75, SD = 2.52) reported similar sleep quality to individuals who did not meet criteria for CUD (M = 6.93, SD = 3.03). Individuals meeting criteria for mild and moderate CUD reported the poorest sleep quality among the groups, suggesting a differentiation within CUD severity. Future research should assess withdrawal and cannabis use frequency among individuals who meet criteria for CUD to further elucidate disturbances in sleep quality among those with CUD.

Acute sleep interventions as an avenue for treatment of trauma-associated disorders

Scientific evidence that acute, posttrauma sleep disturbances (eg, nightmares and insomnia) can contribute significantly to the pathogenesis of trauma-induced disorders is compelling. Sleep disturbances precipitating from trauma are uniquely predictive of daytime posttrauma symptom occurrence and severity, as well as subsequent onset of mental health disorders, including post-traumatic stress disorder. Conversely, adequate sleep during the acute posttrauma period is associated with reduced likelihood of adverse mental health outcomes. These findings, which are broadly consistent with what is known about the role of sleep in the regulation of emotion, suggest that the acute posttrauma period constitutes a "window of opportunity" during which treatment of sleep disturbances may be especially effective for preventing or mitigating progression of aberrant psychophysiological processes. At this point, the weight of the scientific evidence supporting this possibility warrants initiation of clinical trials to confirm the benefits of targeted prophylactic sleep enhancement, and to establish treatment guidelines as appropriate.

CITATION

Swift KM, Thomas CL, Balkin TJ, Lowery-Gionta EG, Matson LM. Acute sleep interventions as an avenue for treatment of trauma-associated disorders. J Clin Sleep Med. 2022;18(9):2291-2312.

Tonic endocannabinoid signaling supports sleep through development in both sexes

Sleep is an essential behavior that supports brain function and cognition throughout life, in part by acting on neuronal synapses. The synaptic signaling pathways that mediate the restorative benefits of sleep are not fully understood, particularly in the context of development. Endocannabinoids (eCBs) including 2-arachidonyl glycerol (2-AG) and anandamide (AEA), are bioactive lipids that activate cannabinoid receptor, CB1, to regulate synaptic transmission and mediate cognitive functions and many behaviors, including sleep. We used targeted mass spectrometry to measure changes in forebrain synaptic eCBs during the sleep/wake cycle in juvenile and adolescent mice of both sexes. We find that eCBs lack a daily rhythm in juvenile mice, while in adolescents AEA and related oleoyl ethanolamide are increased during the sleep phase in a circadian manner. Next, we manipulated the eCB system using selective pharmacology and measured the effects on sleep behavior in developing and adult mice of both sexes using a noninvasive piezoelectric home-cage recording apparatus. Enhancement of eCB signaling through inhibition of 2-AG or AEA degradation, increased dark-phase sleep amount and bout length in developing and adult males, but not in females. Inhibition of CB1 by injection of the antagonist AM251 reduced sleep time and caused sleep fragmentation in developing and adult males and females. Our data suggest that males are more sensitive to the sleep-promoting effects of enhanced eCBs but that tonic eCB signaling supports sleep behavior through multiple stages of development in both sexes. This work informs the further development of cannabinoid-based therapeutics for sleep disruption.

Cannabinoids, Insomnia, and Other Sleep Disorders

Sleep disturbances are often cited as a primary reason for medicinal cannabis use, and there is increasing clinical interest in the therapeutic potential of cannabinoids in treating sleep disorders. Burgeoning evidence suggests a role of the endocannabinoid system in regulating the circadian sleep-wake cycle, highlighting a potential avenue for developing novel therapeutics. Despite widespread use of cannabis products as sleep aids globally, robustly designed studies verifying efficacy in sleep-disordered populations are limited. Although some study outcomes have suggested cannabinoid utility in insomnia disorder and sleep apnea, most studies to date are limited by small sample sizes, lack of rigorously controlled study designs, and high risk of bias. This critical review summarizes the current evidence for the use of cannabinoids as a treatment for sleep disorders and provides an overview of endocannabinoid modulation of sleep-wake cycles, as well as the sleep-modulating effects of plant-derived cannabinoids such as delta-9-tetrahydrocannbinol, cannabidiol, and cannabinol. The review also discusses practical considerations for clinicians regarding cannabinoid formulations, routes of administration, respiratory concerns, dosing, potential side effects, drug interactions, and effects relevant to driving, tolerance, and withdrawal. Although current interest in, and uptake of, medicinal cannabis use for sleep disorders may have surpassed the evidence base, there is a strong rationale for continued investigation into the therapeutic potential of cannabinoids.

A Systematic Review and Meta-Analysis on the Effects of Exercise on the Endocannabinoid System

Introduction: The endocannabinoid (eCB) system plays a key role in maintaining homeostasis, including the regulation of metabolism and stress responses. Chronic stress may blunt eCB signaling, and disruptions in eCB signaling have been linked to stress-related psychiatric disorders and physical health conditions, including anxiety, depression, post-traumatic stress disorder (PTSD), diabetes, and obesity. Pharmacological and nonpharmacological behavioral interventions (e.g., exercise) that target the eCB system may be promising therapeutic approaches for the prevention and treatment of stress-related diseases. In this study, we perform a systematic review and the first meta-analysis to examine the impact of exercise on circulating eCB concentrations. Materials and Methods: We performed a review of the MEDLINE (PubMed) database for original articles examining the impact of exercise on eCBs in humans and animal models. A total of 262 articles were screened for initial inclusion. Results: Thirty-three articles (reporting on 57 samples) were included in the systematic review and 10 were included in the meta-analysis. The majority of samples that measured anandamide (AEA) showed a significant increase in AEA concentrations following acute exercise (74.4%), whereas effects on 2-arachidonoylglycerol (2-AG) were inconsistent. The meta-analysis, however, revealed a consistent increase in both AEA and 2-AG following acute exercise across modalities (e.g., running, cycling), species (e.g., humans, mice), and in those with and without pre-existing health conditions (e.g., PTSD, depression). There was substantial heterogeneity in the magnitude of the effect across studies, which may relate to exercise intensity, physical fitness, timing of measurement, and/or fasted state. Effects of chronic exercise were inconsistent. Conclusions: Potential interpretations and implications of exercise-induced mobilization of eCBs are discussed, including refilling of energy stores and mediating analgesic and mood elevating effects of exercise. We also offer recommendations for future work and discuss therapeutic implications for exercise in the prevention and treatment of stress-related psychopathology.

A Placebo-Controlled Trial of Cannabinoid Treatment for Disruptive Behavior in Children and Adolescents with Autism Spectrum Disorder: Effects on Sleep Parameters as Measured by the CSHQ

Autism spectrum disorder (ASD) is often associated with debilitating sleep disturbances. While anecdotal evidence suggests the positive effect of cannabinoids, randomized studies are lacking. Here, we report the effects of cannabinoid treatment on the sleep of 150 children and adolescents with ASD, as part of a double-blind, placebo-controlled study that assessed the impact of cannabinoid treatment on behavior (NCT02956226). Participants were randomly assigned to one of the following three treatments: (1) whole-plant cannabis extract, containing cannabidiol (CBD) and Δ9-Tetrahydrocannabinol (THC) in a 20:1 ratio, (2) purified CBD and THC extract in the same ratio, and (3) an oral placebo. After 12 weeks of treatment (Period 1) and a 4-week washout period, participants crossed over to a predetermined, second 12-week treatment (Period 2). Sleep disturbances were assessed using the Children’s Sleep-Habit Questionnaire (CSHQ). We found that the CBD-rich cannabinoid treatment was not superior to the placebo treatment in all aspects of sleep measured by the CSHQ, including bedtime resistance, sleep-onset delay, and sleep duration. Notably, regardless of the treatment (cannabinoids or placebo), improvements in the CSHQ total score were associated with improvements in the autistic core symptoms, as indicated by the Social Responsiveness Scale total scores (Period 1: r = 0.266, p = 0.008; Period 2: r = 0.309, p = 0.004). While this study failed to demonstrate that sleep improvements were higher with cannabinoids than they were with the placebo treatment, further studies are required.

Sleep Quality: A Narrative Review on Nutrition, Stimulants, and Physical Activity as Important Factors

Sleep is a cyclically occurring, transient, and functional state that is controlled primarily by neurobiological processes. Sleep disorders and insomnia are increasingly being diagnosed at all ages. These are risk factors for depression, mental disorders, coronary heart disease, metabolic syndrome, and/or high blood pressure. A number of factors can negatively affect sleep quality, including the use of stimulants, stress, anxiety, and the use of electronic devices before sleep. A growing body of evidence suggests that nutrition, physical activity, and sleep hygiene can significantly affect the quality of sleep. The aim of this review was to discuss the factors that can affect sleep quality, such as nutrition, stimulants, and physical activity.

A fluorescent sensor for spatiotemporally resolved imaging of endocannabinoid dynamics in vivo

Endocannabinoids (eCBs) are retrograde neuromodulators with important functions in a wide range of physiological processes, but their in vivo dynamics remain largely uncharacterized. Here we developed a genetically encoded eCB sensor called GRAB_eCB2.0. GRAB_eCB2.0 consists of a circular-permutated EGFP and the human CB1 cannabinoid receptor, providing cell membrane trafficking, second-resolution kinetics with high specificity for eCBs, and shows a robust fluorescence response at physiological eCB concentrations. Using GRAB_eCB2.0, we monitored evoked and spontaneous changes in eCB dynamics in cultured neurons and acute brain slices. We observed spontaneous compartmentalized eCB transients in cultured neurons and eCB transients from single axonal boutons in acute brain slices, suggesting constrained, localized eCB signaling. When GRAB_eCB2.0 was expressed in the mouse brain, we observed foot shock-elicited and running-triggered eCB signaling in the basolateral amygdala and hippocampus, respectively. In a mouse model of epilepsy, we observed a spreading wave of eCB release that followed a Ca²⁺ wave through the hippocampus. GRAB_eCB2.0 is a robust probe for eCB release in vivo.

What's new in insomnia? Diagnosis and treatment

Although, insomnia is one of the most common diseases that health professionals face in their practice, it receives little attention in medical training. Diagnosis is based on a careful history taking, and physicians must be aware of the diagnostic criteria. Insomnia should not be considered a symptom, but a comorbid condition. Although cognitive behavioral therapy (CBT) has been the mainstay treatment for insomnia for many years, it is usually regarded as a novel therapeutic strategy, both because of scarcity of qualified psychologists and of limited knowledge about insomnia among physicians. GABA receptor acting drugs are being abandoned in the treatment of insomnia because of abuse and dependence potential and accident risk. Two main current therapeutic options with the best scientific evidence are the tricyclic antidepressant, doxepin, and a new melatoninergic receptor agonist, ramelteon. Newer drugs to treat insomnia are in the pipeline. Hypocretine blocking agents will be marketed in the near future.

Altered sleep during spontaneous cannabinoid withdrawal in male mice

Cessation of cannabinoid use in humans often leads to a withdrawal state that includes sleep disruption. Despite important health implications, little is known about how cannabinoid abstention affects sleep architecture, in part because spontaneous cannabinoid withdrawal is difficult to model in animals. In concurrent work we report that repeated administration of the high-efficacy cannabinoid 1 (CB1) receptor agonist AM2389 to mice for 5 days led to heightened locomotor activity and paw tremor following treatment discontinuation, potentially indicative of spontaneous cannabinoid withdrawal. Here, we performed parallel studies to examine effects on sleep. Using implantable electroencephalography (EEG) and electromyography (EMG) telemetry we examined sleep and neurophysiological measures before, during, and after 5 days of twice-daily AM2389 injections. We report that AM2389 produces decreases in locomotor activity that wane with repeated treatment, whereas discontinuation produces rebound increases in activity that persist for several days. Likewise, AM2389 initially produces profound increases in slow-wave sleep (SWS) and decreases in rapid eye movement (REM) sleep, as well as consolidation of sleep. By the third AM2389 treatment, this pattern transitions to decreases in SWS and total time sleeping. This pattern persists following AM2389 discontinuation and is accompanied by emergence of sleep fragmentation. Double-labeling immunohistochemistry for hypocretin/orexin (a sleep-regulating peptide) and c-Fos (a neuronal activity marker) in lateral hypothalamus revealed decreases in c-Fos/orexin+ cells following acute AM2389 and increases following discontinuation, aligning with the sleep changes. These findings indicate that AM2389 profoundly alters sleep in mice and suggest that sleep disruption following treatment cessation reflects spontaneous cannabinoid withdrawal.

Astroglial cannabinoid signaling and behavior

In neuroscience, the explosion of innovative and advanced technical accomplishments is fundamental to understanding brain functioning. For example, the possibility to distinguish glial and neuronal activities at the synaptic level and/or the appearance of new genetic tools to specifically monitor and manipulate astroglial functions revealed that astrocytes are involved in several facets of behavioral control. In this sense, the discovery of functional presence of type-1 cannabinoid receptors in astrocytes has led to identify important behavioral responses mediated by this specific pool of cannabinoid receptors. Thus, astroglial type-1 cannabinoid receptors are in the perfect place to play a role in a complex scenario in which astrocytes sense neuronal activity, release gliotransmitters and modulate the activity of other neurons, ultimately controlling behavioral responses. In this review, we will describe the known behavioral implications of astroglial cannabinoid signaling and highlight exciting unexplored research avenues on how astroglial cannabinoid signaling could affect behavior.

A narrative review of molecular mechanism and therapeutic effect of Cannabidiol (CBD)

Cannabidiol (CBD) is an abundant non-psychoactive phytocannabinoid in Cannabis extracts which has high affinity on a series of receptors, including type 1 cannabinoid receptor (CB1), type 2 cannabinoid receptor (CB2), GPR55, transient receptor potential vanilloid (TRPV), and peroxisome proliferator-activated receptor gamma (PPARγ). By modulating the activities of these receptors, CBD exhibits multiple therapeutic effects, including neuroprotective, antiepileptic, anxiolytic, antipsychotic, anti-inflammatory, analgesic and anti-cancer properties. CBD could also be applied to treat or prevent COVID-19 and its complications. Here, we provide a narrative review of CBD's applications in human diseases: from mechanism of action to clinical trials.

Higher risk, higher reward? Self‐reported effects of real‐world cannabis use in Parkinson's disease

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Stimulants and Depressor Drugs in the Sleep-Wake Cycle Modulation: The case of alcohol and cannabinoids

A complex neurobiological network drives the sleep-wake cycle. In addition, external stimuli, including stimulants or depressor drugs, also influence the control of sleep. Here we review the recent advances that contribute to the comprehensive understanding of the actions of stimulants and depressor compounds, such as alcohol and cannabis, in sleep regulation. The objective of this review is to highlight the neurobiological mechanism engaged by alcohol and cannabis in sleep control.

The Effects of Cannabinoids on Sleep

The use of cannabis products to help with sleep and various other medical conditions by the public has increased significantly in recent years. Withdrawal from cannabinoids can lead to sleep disturbance. Here, we describe a patient who developed significant insomnia leading to worsening anxiety, mood, and suicidal ideation in the setting of medical cannabis withdrawal, prompting presentation to the Emergency Department and inpatient admission. There is a limited evidence base for the use of cannabis products for sleep. We provide a comprehensive review evaluating the literature on the use of cannabis products on sleep, including an overview of cannabis and related psychoactive compounds, the current state of the law as it pertains to the prescribing and use of these substances, and potential side effects and drug interactions. We specifically discuss the impact of cannabis products on normal sleep and circadian sleep-wake rhythms, insomnia, excessive daytime sleepiness, sleep apnea, parasomnias, and restless legs syndrome. We also describe the effects of cannabis withdrawal on sleep and how this increases relapse to cannabis use. Most of the studies are observational but the few published randomized controlled trials are reviewed. Our comprehensive review of the effects of cannabis products on normal sleep and sleep disorders, relevant to primary care providers and other clinicians evaluating and treating patients who use these types of products, shows that cannabis products have minimal to no effects on sleep disorders and may have deleterious effects in some individuals. Further research examining the differential impact of the various types of cannabinoids that are currently available on each of these sleep disorders is required.