Background Evidence on factors associated with cannabis for medical purposes (CMP) authorizations among Veterans Affairs Canada (VAC) clients remains limited and inconsistent, particularly concerning mental health and posttraumatic stress disorder (PTSD), a leading indication for use. We investigated demographic, clinical and service characteristics associated with VAC authorizations for CMP reimbursement. Method We linked VAC administrative CMP program data with responses from the 2019 Life After Services Studies cross-sectional survey of Regular Force veterans released between 1998 and 2018. Multivariable logistic regressions examined associations between CMP reimbursement (yes/no) and demographic, clinical and well-being factors, with analyses stratified by PTSD status. Results Among 1,289 respondents (weighted n=33,131), 18.4% were authorized for CMP reimbursement. Younger age (<40 vs. ≥60 years: OR 4.78, 95% CI: 2.24–10.21), unemployment with inability to work vs. employed (OR 3.10, 95% CI: 1.78–5.40), land service vs. air (OR 2.07, 95% CI: 1.22–3.50), PTSD (OR 2.81, 95% CI: 1.69–4.66), anxiety (OR 2.32, 95% CI: 1.45–3.70), and severe pain vs. no pain (OR 3.61, 95% CI: 1.97–6.60) were independently associated with authorization. Unemployment and severe pain were consistent correlates across PTSD strata. Among those without PTSD, younger age, multiple physical conditions, and frequent mental health visits were significant; among those with PTSD, shorter service, witnessing destruction, and suicidal ideation were additional factors. Conclusions CMP authorization patterns among Canadian veterans reflect the intersection of mental health, pain, and functional impairment, with variation by PTSD status. These findings underscore the need for longitudinal research on CMP mechanisms, effectiveness and safety. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement Yes ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The respondents who provided permission for linkage with VAC administrative data were used for this study. The data collection and data access procedures for LASS 2019 were reviewed and approved by policy committees at Statistics Canada, which provide similar functions to a research ethics board, as previously reported. This study was approved by the University of Ottawa Research Ethics Board (H-02-22-7491). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The data that support the findings of this study were obtained from Veterans Affairs Canada (VAC). Due to ethical, legal and privacy restrictions, these data are not publicly available. De-identified aggregate data and analysis code may be available from the corresponding author on reasonable request.

Background The present study investigated whether sleep deprivation affects attention capture in young and older adults using event-related potentials (ERPs). Methods Eleven young adults (20-30 y) and nine older adults (60-70 y) were tested following both normal sleep (NS) and total sleep deprivation (TSD). ERPs were recorded during an auditory discrimination task consisting of standard and deviant stimuli. Results Deviant stimuli elicited the MMN, P3a, and RON ERPs. TSD attenuated the differences in reaction times between standards and deviants in young adults but not older adults. The P3a was attenuated in older adults compared to young adults. Older adults had a larger RON amplitude compared to young adults following NS, but not TSD. Conclusions The reduced P3a and the absence of behavioral performance alteration in the older group suggests that older adults may utilize different neural processing strategies compared to younger adults to compensate for age-related declines in neural resources for attention capture. Sleep loss influenced age-related differences on the RON, suggesting that older adults may have reduced access to compensatory strategies following sleep loss.

The first aim of the present review is to provide an in-depth description of the cannabinoids and their known effects at various neuronal receptors. It reveals that cannabinoids are highly diverse, and recent work has highlighted that their effects on the central nervous system (CNS) are surprisingly more complex than previously recognized. Cannabinoid-sensitive receptors are widely distributed throughout the CNS where they act as primary modulators of neurotransmission. Secondly, we examine the role of cannabinoid receptors at key brain sites in the control of fear and anxiety. While our understanding of how cannabinoids specifically modulate these networks is mired by their complex interactions and diversity, a plausible framework(s) for their effects is proposed. Finally, we highlight some important knowledge gaps in our understanding of the mechanism(s) responsible for their effects on fear and anxiety in animal models and their use as therapeutic targets in humans. This is particularly important for our understanding of the phytocannabinoids used as novel clinical interventions.

This study aimed to evaluate changes in sleep during the COVID‐19 outbreak, and used data‐driven approaches to identify distinct profiles of changes in sleep‐related behaviours. Demographic, behavioural and psychological factors associated with sleep changes were also investigated. An online population survey assessing sleep and mental health was distributed between 3 April and 24 June 2020. Retrospective questions were used to estimate temporal changes from before to during the outbreak. In 5,525 Canadian respondents (67.1% females, 16–95 years old: Mean ± SD = 55.6 ± 16.3 years), wake‐up times were significantly delayed relative to pre‐outbreak estimates (p < .001, ηp2 = 0.04). Occurrences of clinically meaningful sleep difficulties significantly increased from 36.0% before the outbreak to 50.5% during the outbreak (all p < .001, g ≥ 0.27). Three subgroups with distinct profiles of changes in sleep behaviours were identified: “Reduced Time in Bed”, “Delayed Sleep” and “Extended Time in Bed”. The “Reduced Time in Bed” and “Delayed Sleep” subgroups had more adverse sleep outcomes and psychological changes during the outbreak. The emergence of new sleep difficulties was independently associated with female sex, chronic illnesses, being employed, family responsibilities, earlier wake‐up times, higher stress levels, as well as heavier alcohol use and television exposure. The heterogeneity of sleep changes in response to the pandemic highlights the need for tailored interventions to address sleep problems.

BOOK REVIEW article Front. Psychol., 28 May 2021 | https://doi.org/10.3389/fpsyg.2021.697434

Background: Δ9-Tetrahydrocannabinol (THC, a CB1 receptor agonist) and Cannabidiol (CBD, a non-competitive antagonist of endogenous CB1 and CB2 ligands) are two primary components of Cannabis species, and may modulate fear learning in mammals. The CB1 receptor is widely distributed throughout the cortex and some limbic regions typically associated with fear learning. Humans with posttraumatic disorder (PTSD) have widespread upregulation of CB1 receptor density and reduced availability of endogenous cannabinoid anandamide, suggesting a role for the endocannabinoid system in PTSD. Pharmacological blockade of memory reconsolidation following recall of a conditioned response modulates the expression of learned fear and may represent a viable target for the development of new treatments for PTSD. In this study, we focused on assessing the impact of the key compounds of the marijuana plant both singly and, more importantly, in concert on attenuation of learned fear. Specifically, we assessed the impact of THC, CBD, and/or the remaining plant materials (post-extraction; background material), on reconsolidation of learned fear. Method: Male Sprague-Dawley rats received six 1.0 mA continuous foot shocks (contextual training). Twenty-four hours later, rats were re-exposed to the context. Immediately following memory retrieval (recall) rats received oral administration of low dose THC, high dose THC, CBD, CBD + low THC, CBD + high THC [as isolated phytochemicals and, in separate experiments, in combination with plant background material (BM)]. Rodents were tested for freezing response context re-exposure at 24 h and 7 days following training. Results: CBD alone, but not THC alone, significantly attenuated fear memory reconsolidation when administered immediately after recall. The effect persisted for at least 7 days. A combination of CBD and THC also attenuated the fear response. Plant BM also significantly attenuated reconsolidation of learned fear both on its own and in combination with THC and CBD. Finally, THC attenuated reconsolidation of learned fear only when co-administered with CBD or plant BM. Conclusion: CBD may provide a novel treatment strategy for targeting fear-memories. Furthermore, plant BM also significantly attenuated the fear response. However, whereas THC alone had no significant effects, its effects were modulated by the addition of other compounds. Future research should investigate some of the other components present in the plant BM (such as terpenes) for their effects alone, or in combination with isolated pure cannabinoids, on fear learning.

Background: Souroubea sympetala Gilg. is a neotropical vine native to Central America, investigated as part of a targeted study of the plant family Marcgraviaceae. Our previous research showed that extract of S. sympetala leaf and small branch extract had anxiolytic effects in animals and acts as an agonist for the GABA(A) receptor at the benzodiazepine binding site. To date, the potential effects of S. sympetala and its constituents on reconsolidation have not been assessed. Reconsolidation, the process by which formed memories are rendered labile and susceptible to change, may offer a window of opportunity for pharmacological manipulation of learned fear. Here, we assessed the effects of S. sympetala crude extract and isolated phytochemicals (orally administered) on the reconsolidation of conditioned fear. In addition, we explored whether betulin (BE), a closely related molecule to betulinic acid (BA, an active principal component of S. sympetala), has effects on reconsolidation of learned fear and whether BE may synergize with BA to enhance attenuation of learned fear. Method: Male Sprague-Dawley rats received six 1.0-mA continuous foot shocks (contextual training). Twenty-four hours later, rats were re-exposed to the context (but in the absence of foot shocks). Immediately following memory retrieval (recall), rats received oral administration of S. sympetala extract at various doses (8-75 mg/kg) or diazepam (1 mg/kg). In separate experiments, we compared the effects of BA (2 mg/kg), BE (2 mg/kg), and BA + BE (2 mg/kg BA + 2 mg/kg BE). The freezing response was assessed either 24 h later (day 3) or 5 days later (day 7). Effects of phytochemicals on fear expression were also explored using the elevated plus maze paradigm. Results: S. sympetala leaf extract significantly attenuated the reconsolidation of contextual fear at the 25- and 75-mg/kg doses, but not at the 8-mg/kg dose. Furthermore, BA + BE, but not BA or BE alone, attenuated the reconsolidation of learned fear and exerted an anxiolytic-like effect on fear expression.

TThere are two temporal delay effects used to describe the reoccurrence of day events in dreams. The day-residue effect is the reflection of events in dreams 1-2 nights after its occurrence and has been observed in typical and unusual day events. The dream-lag effect is the re-surfacing of daily events approximately a week after and more likely to occur when personally significant events are encountered. Further, degree of emotional intensity affects likelihood of day incorporation. The current study explores the temporal pattern of incorporation of emotionally salient day events. A sample of undergraduate psychology students (N = 45) completed a daily journal of events containing emotional importance. Nightly dream journals were also maintained for one week and were required to include as much detail as possible. Independent judges rated the number of correspondences between day events and the subsequent 7 dreams. Analysis revealed a main effect of day, main effect of emotion; negative emotions (p < 0.05) and neutral items (p < 0.01) were much more likely to be incorporated in dreams than positive emotions. In addition, there were significantly more incorporations on day 1 versus day 5 (p < 0.05) and day 7 (p < 0.05) for both negative and neutral correspondences. Overall, correspondences indicated a day-residue effect, but no dream-lag effect.

Research suggests sleep plays a role in the consolidation of recently acquired memories for long-term storage. rapid eye movement (REM) sleep has been shown to play a complex role in emotional-memory processing, and may be involved in subsequent waking-day emotional reactivity and amygdala responsivity. Interaction of the hippocampus and basolateral amygdala with the medial-prefrontal cortex is associated with sleep-dependent learning and emotional memory processing. REM is also implicated in post-traumatic stress disorder (PTSD), which is characterized by sleep disturbance, heightened reactivity to fearful stimuli, and nightmares. Many suffers of PTSD also exhibit dampened medial-prefrontal cortex activity. However, the effects of PTSD-related brain changes on REM-dependent consolidation or the notion of ‘over-consolidation’ (strengthening of memory traces to such a degree that they become resistant to extinction) have been minimally explored. Here, we posit that (in addition to sleep architecture changes) the memory functions of REM must also be altered in PTSD. We propose a model of REM-dependent consolidation of learned fear in PTSD and examine how PTSD-related brain changes might interact with fear learning. We argue that reduced efficacy of inhibitory medial-prefrontal pathways may lead to maladaptive processing of traumatic memories in the early stages of consolidation after trauma.

Abstract Rhodiola rosea is a plant with adaptogenic qualities used by Inuit populations of Nunavik, Quebec (Canada) for general mental and physical rejuvenation. Previous studies have demonstrated that the Canadian populations of R. rosea significantly attenuate the expression of learned fear and anxiety-like behaviors in rodent models. In order to further characterize the anxiolytic activity of Nunavik R. rosea, experiments were conducted to assess the effects of oral administration of the plant extract on both the fear-potentiated startle response and corticosterone levels. Findings suggest that oral administration of R. rosea ethanolic extract (75 mg/kg) significantly attenuated fear-potentiated startle, but did not produce any effects on stress-induced secretion of corticosterone.

Recent research has suggested that some of the inter-individual variation in sleep spindle activity is due to innate learning ability. Sleep spindles have also been observed to vary following learning in both young and older adults. We examined the effect of procedural task acquisition on sleep stages and on sleep spindles in an adolescent sample. Participants were 32 adolescents (17 females) between the ages of 12 and 19 years. Spindle activity was examined in three different frequency ranges: 11.00-13.50 Hz (slow), 13.51-16.00 Hz (fast), and 16.01-18.50 Hz (superfast). No changes in spindle density were observed after successful learning of the pursuit rotor task. This result was in contrast to a number of studies reporting spindle density increases following successful learning. In the present study, participants who successfully learned the task showed no changes in their sleep stage proportions, but participants who were not successful showed a decrease in the proportion of stage 2 and increases in both SWS and REM sleep. We suggest that these changes in the sleep stages are consistent with the two stage model of sleep and memory proposed by Smith et al. (2004a).

The main goal of the current study was to determine the reliability of Garfield’s (1996) dream themes of the deceased in a larger sample of dream data. A total of 76 dreams were collected and scored by two judges to determine inter-rater reliability. It was found that Garfield’s (1996) dream themes as a whole where not reliable. However, based on her previous work and others, eight new dream themes of the deceased were developed. It was found that these themes had acceptable inter-rater reliability. This research is a necessary step forward in dreams in bereavement research.

Although animal models have been useful for uncovering nuclei responsible for the mediation of different sleep states, these techniques are rarely viable methods for studying mentation during sleep (both because of ethical considerations, and because animals cannot report the content of their dreams). Relevant animal models of sleep disorders and states are often neglected rather than used to inform future directions in dream research with human subjects. Here findings from animal models of sleep that may pertain to dream research are presented to highlight that overlap between research fields can provide unique insights into the neurobiology of dreaming. It is suggested that such areas of overlap should act to guide future targets in dream research with human subjects.

This study utilized both quantitative and qualitative statistical methods to examine dreams in 22 University students and the effects of meditation on waking day depression levels (BDI), trait anxiety levels (BAI-T) and dream imagery. Results are consistent with previous research in that mood levels changed over the course of the meditation period, specifically, moods benefit from meditation. Specific dream imagery correlated with both depression and anxiety scores, such as scene changes and animals in dreams. There were multiple significant correlations found between dream content and discoveries before and after meditation. This research illustrates that meditation affects dream imagery and mood. Implications for future research are discussed as well as applications of dream work and meditation in applied practice.

Participants in the current study were 75 males, including 25 Canadian soldiers, 25 heavy gamers who play military based video games such as "Call of Duty," and a control group comprised of 25 males. One dream per participant was analyzed using Hall and Van de Castle content analysis guidelines, including aggression, threat, and previously established scales for intensity of aggression and emotion. The dreams of soldiers had a higher frequency of both aggression and threat, and were also more intense in aggression and emotion than both the heavy gamers and the controls. These findings suggest that exposure to real life violence and threat (as well as the emotional significance of the experience) is more frequently incorporated into dream imagery than simulated or virtual threat. Limitations and directions for future studies are discussed.

Previous research in the field of sleep mentation (dreaming) has focused on the use of subjective reports of experience for measuring emotion in dream content. However, emotions are seldom explicitly mentioned in dream reports, and a more substantial method for empirically assessing the emotionality of sleep mentation imagery to the individual is necessary to assess qualitative differences between REM and NREM mentation. Here a previously established research method has been compared with a physiological measure of emotional arousal in order to determine whether physiological measures might be used as a reliable research tool for characterizing the emotional salience of dream images to the dreamer. Findings suggest that the use of Galvanic Skin Response (GSR) may be a valuable research tool for assessing emotion in sleep mentation.

Previous research has found evidence of relationships among sleep states and memory sources. However, the use of text-analysis of dream reports limits the validity of measures of emotion. In order to determine whether dreams reflect emotionally significant memories, a new technique for measuring the emotional significance of dream imagery to the dreamer was designed (using a modified emotional Stroop task). Results support the idea that sleep mentation imagery (most likely from REM) may reflect emotional memory, and suggest that modified cognitive tasks (such as the Emotional Stroop) may serve as novel methodological approaches for studying sleep mentation.

Previous research has found evidence of relationships among sleep states and memory consolidation. However, no dominant models of sleep mentation (dreaming) account for the relationship between sleep and memory, despite the fact that the underlying neural processes of offline memory consolidation and sleep mentation happen simultaneously (and are therefore produced by the same brain state). In addition, experimental brain research contradicts what dominant neurological models of sleep mentation predict. Here a model of dream generation that agrees with empirical findings on dreams, and which is based on the neural process of memory consolidation during sleep, is proposed. The implications of the model are such that is suggests sleep state mentation may actually be a by-product (or readout) of the consolidation of memories produced by non-random cortical/sub-cortical reactivation during REM and Non-REM sleep (processes which are known, and are necessary for normal human memory function).

Previous research has demonstrated that dream recall rates differ between REM and NREM sleep. However, the neurological mechanisms responsible for this difference are not fully understood. Here recent research is discussed regarding the characteristics of neural reactivation during REM and NREM in response to pre-sleep memory acquisition. It is proposed that differential reactivation of cortical and subcortical areas during REM and NREM may offer one possible explanation for why there are differences in dream recall rates from REM and NREM sleep.