Age-related Patterns of Medical Cannabis Use: A Survey of Authorized Patients in Canada.

Objective: An increasing number of Canadians are registering as authorized users of medical cannabis. Older patients comprise a growing subset of this population; however, relatively little information exists around age-related patterns of medical cannabis use. Methods: The Canadian Cannabis Patient Survey (CCPS) is a large cross-sectional survey of authorized medical cannabis patients in Canada. This publication summarizes the results of the CCPS 2021, with a focus on age-related outcomes and the elderly sub-population. Results: The survey was completed by 2,697 patients. The mean age of participants was 54.3 years of age and the proportion of female respondents was 49.1%. Among older patients, pain was the most common symptom, while anxiety was the most common symptom reported by younger patients. Older patients exhibited a significant preference for oral administration over inhalation of medical cannabis when compared to younger patients, respectively (p>0.05). Among patients taking prescription opioids, most of whom were older patients, 54% reported a decrease in use concurrent with medical cannabis. Conclusions: Older patients comprise a growing subset of medical cannabis patients, which is also reflected in CCPS participants over time. This patient population exhibits different patterns of use compared to their younger counterparts, preferring high CBD orally ingested formulations, which they use primarily to treat pain-related illnesses/symptoms. Overall, study participants reported that cannabis had a high degree of efficacy in alleviating their illness/symptoms, and many reported a reduction in their use of prescription opioids, alcohol, tobacco, and other substances.

The Global Psychedelic Survey: Consumer characteristics, patterns of use, and access in primarily anglophone regions around the world.

OBJECTIVES: Despite advancements in policies governing psychedelic substances globally, our understanding of real-world psychedelic use and its variations across international jurisdictions remains limited. We implemented the Global Psychedelic Survey (GPS) to capture information about psychedelic consumer characteristics, access, and usage patterns around the world. METHODS: The GPS was administered online in Spring 2023 to English-speaking adults (≥21 years) who use(d) psychedelics. We categorized survey responses into major catchment regions (Canada/US, Europe/UK, Australia/NZ, All Other). We used descriptive and bivariable statistics to characterize consumers' socio-demographic characteristics, psychedelic access sources, and usage patterns. We examined regional differences in psychedelic use patterns using multinomial logistic regression. RESULTS: We analyzed 6379 responses from 85 countries including Canada/US (n = 4434), Europe/UK (n = 771), Australia/NZ (n = 864), and Other (n = 310). Psilocybin, LSD, and MDMA were the most used psychedelics and personal growth was the most common use motive across all catchments. There were significant regional differences in psychedelic use patterns, including types of psychedelics used (e.g., less ibogaine use in Europe/UK and Australia/NZ relative to Canada/US), frequency of use (e.g., lower frequency use in Australia/NZ relative to Canada/US), motivations for use (e.g., less therapeutic use in Europe/UK and Other relative to Canada/US), and types of dosing regimens (e.g., more "micro"-dosing in Canada/US). DISCUSSION: In this large sample of adult psychedelic consumers from regions around the world, infrequent psychedelic use centered around life enhancement was common. Respondents indicated preference for legal access via quality-controlled sources. Jurisdictional differences in access and usage patterns likely reflect region-specific regulations and traditional practices. Further research should explore opportunities to increase representation of non-White respondents in psychedelic research via translation of studies into several languages and incorporation of culturally reflective, community-based study development.

Psychedelic substitution: altered substance use patterns following psychedelic use in a global survey.

Introduction: Recent research suggests that psychedelics may have potential for the treatment of various substance use disorders. However, most studies to date have been limited by small sample sizes and neglecting to include non-North American and European populations. Methods: We conducted a global, cross-sectional online survey of adults (n = 5,268, 47.2% women) self-reporting past or current psychedelic use and investigated whether psychedelic use was associated with changes in use of other substances. Results: Nearly three-quarters (70.9%; n = 3,737/5,268) reported ceasing or decreasing use of one or more non-psychedelic substances after naturalistic psychedelic use. Among those with previous use, 60.6% (n = 2,634/4,344) decreased alcohol use, 55.7% (n = 1,223/2,197) decreased antidepressant use, and 54.2% (n = 767/1,415) decreased use of cocaine/crack. Over a quarter of the sample indicated that their decrease in substance use persisted for 26 weeks or more following use of a psychedelic. Factors associated with decreased use included a motivation to either decrease one's substance use or self-treat a medical condition. Importantly, 19.8% of respondents also reported increased or initiated use of one or more other substances after psychedelic use, with illicit opioids (14.7%; n = 86/584) and cannabis (13.3%; n = 540/4,064) having the highest proportions. Factors associated with increased substance use included having a higher income and residing in Canada or the US. Discussion: Although limited by cross-sectional study design, this large observational study will help inform future studies aiming to investigate the relationship between substance use patterns and psychedelic use.

A small clinical trial of vaporized cannabis for PTSD: suggestive results and directions for future study.

The last few decades have seen increasing interest in the use of cannabis for post-traumatic stress disorder (PTSD). Recent attempts to evaluate the clinical efficacy of cannabis for PTSD were inconclusive and generalizability was limited by undesirable features of the study drug. The present clinical trial evaluated the effects of a commercially available chemovar that was delivered by vaporization. The study was designed as a randomized placebo-controlled cross-over study with three conditions; however, only five individuals completed the trial, and analysis of the placebo effect was not possible. Results identified positive changes consistent with medium-sized within-subject effects for cannabis in the treatment of PTSD. Positive trending results and high patient need mandate future studies of cannabis for the treatment of PTSD.

The Relationship Between Naturalistic Psychedelic Use and Clinical Care in Canada.

Naturalistic psychedelic use among Canadians is common. However, interactions about psychedelic use between patients and clinicians in Canada remain unclear. Via an anonymous survey, we assessed health outcomes and integration of psychedelic use with health care providers (HCP) among Canadian adults reporting past use of a psychedelic. The survey included 2,384 participants, and most (81.2%) never discussed psychedelic use with their HCP. While 33.7% used psychedelics to self-treat a health condition, only 4.4% used psychedelics with a therapist and 3.6% in a clinical setting. Overall, 44.8% (n = 806) of participants were aware of substance testing services, but only 42.4% ever used them. Multivariate regressions revealed that therapeutic motivation, higher likelihood of seeking therapist guidance, and non-binary gender identification were significantly associated with higher odds of discussing psychedelics with one's primary HCP. Having used a greater number of psychedelics, lower age, non-female gender, higher education, and a therapeutic motivation were significantly associated with higher odds of awareness of substance testing. We conclude that naturalistic psychedelic use in Canada often includes therapeutic goals but is poorly connected to conventional healthcare, and substance testing is uncommon. Relevant training and education for HCPs is needed, along with more visible options for substance testing.

A tale of two copies: Evolutionary trajectories of moth pheromone receptors.

Pheromone communication is an essential component of reproductive isolation in animals. As such, evolution of pheromone signaling can be linked to speciation. For example, the evolution of sex pheromones is thought to have played a major role in the diversification of moths. In the crop pests Spodoptera littoralis and S. litura, the major component of the sex pheromone blend is (Z,E)-9,11-tetradecadienyl acetate, which is lacking in other Spodoptera species. It indicates that a major shift occurred in their common ancestor. It has been shown recently in S. littoralis that this compound is detected with high specificity by an atypical pheromone receptor, named SlitOR5. Here, we studied its evolutionary history through functional characterization of receptors from different Spodoptera species. SlitOR5 orthologs in S. exigua and S. frugiperda exhibited a broad tuning to several pheromone compounds. We evidenced a duplication of OR5 in a common ancestor of S. littoralis and S. litura and found that in these two species, one duplicate is also broadly tuned while the other is specific to (Z,E)-9,11-tetradecadienyl acetate. By using ancestral gene resurrection, we confirmed that this narrow tuning evolved only in one of the two copies issued from the OR5 duplication. Finally, we identified eight amino acid positions in the binding pocket of these receptors whose evolution has been responsible for narrowing the response spectrum to a single ligand. The evolution of OR5 is a clear case of subfunctionalization that could have had a determinant impact in the speciation process in Spodoptera species.

Shifts in medical cannabis use in Canada during the COVID-19 pandemic. / Changements observés au Canada dans la consommation de cannabis à des fins médicales pendant la pandémie de COVID-19.

INTRODUCTION: The COVID-19 pandemic has had widespread secondary negative health impacts including loss of material security and exacerbation of mental illness in at-risk populations. While increases in the nonmedical use of certain substances, including cannabis, have been observed in samples of the Canadian population, no research has documented COVID-concurrent shifts in medical cannabis use in Canada. METHODS: Data were derived from the 2021 Canadian Cannabis Patient Survey, an online survey administered in May 2021 to people authorized to use medical cannabis recruited from one of two Canadian licensed medical cannabis producers. McNemar tests assessed for changes in past 3-month medical cannabis frequency from before to during the pandemic. We explored correlates of increasing frequency of cannabis use since before the pandemic in bivariable and multivariable logistic models. RESULTS: In total, 2697 respondents (49.1% women) completed the survey. Daily medical cannabis use increased slightly but significantly from before the pandemic (83.2%) to during the pandemic (90.3% at time of survey; p < 0.001). Factors significantly associated with increasing frequency of medical cannabis use included female gender, younger age, pandemic-related job loss, primary cannabis use to manage mental health, prescription drug use and nonmedical cannabis use (p < 0.05). CONCLUSION: There were slight shifts towards higher frequency of medical cannabis use after the onset of the COVID-19 pandemic. While short- and long-term impacts of cannabis use on pandemic-related mental distress are unknown, clinicians working with patients who use medical cannabis should be aware of possible changes in use patterns during the pandemic.

Healthcare provider and medical cannabis patient communication regarding referral and medication substitution: the Canadian context.

BACKGROUND: Patients use medical cannabis for a wide array of illnesses and symptoms, and many substitute cannabis for pharmaceuticals. This substitution often occurs without physician oversight, raising patient safety concerns. We aimed to characterize substitution and doctor-patient communication patterns in Canada, where there is a mature market and national regulatory system for medical cannabis. METHODS: We conducted an anonymous, cross-sectional online survey in May 2021 for seven days with adult Canadian federally-authorized medical cannabis patients (N = 2697) registered with two global cannabis companies to evaluate patient perceptions of Primary Care Provider (PCP) knowledge of medical cannabis and communication regarding medical cannabis with PCPs, including PCP authorization of licensure and substitution of cannabis for other medications. RESULTS: Most participants (62.7%, n = 1390) obtained medical cannabis authorization from their PCP. Of those who spoke with their PCP about medical cannabis (82.2%, n = 2217), 38.6% (n = 857) reported that their PCP had "very good" or "excellent" knowledge of medical cannabis and, on average, were moderately confident in their PCP's ability to integrate medical cannabis into treatment. Participants generally reported higher ratings for secondary care providers, with 82.8% (n = 808) of participants rating their secondary care provider's knowledge about medical cannabis as "very good" or "excellent." Overall, 47.1% (n = 1269) of participants reported substituting cannabis for pharmaceuticals or other substances (e.g., alcohol, tobacco/nicotine). Of these, 31.3% (n = 397) reported a delay in informing their PCP of up to 6 months or more, and 34.8% (n = 441) reported that their PCP was still not aware of their substitution. Older, female participants had higher odds of disclosing cannabis substitution to their PCPs. CONCLUSION: Most of the surveyed Canadian medical cannabis patients considered their PCPs knowledgeable about cannabis and were confident in their PCPs' ability to integrate cannabis into treatment plans. However, many surveyed patients substituted cannabis for other medications without consulting their PCPs. These results suggest a lack of integration between mainstream healthcare and medical cannabis that may be improved through physician education and clinical experience.

The impact of non-medical cannabis legalization and other exposures on retention in longitudinal cannabis research: a survival analysis of a prospective study of Canadian medical cannabis patients.

BACKGROUND: Despite repeated calls by medical associations to gather evidence on the harms and benefits of cannabis, there are ongoing methodological challenges to conducting observational and clinical studies on cannabis, including a high rate of patients that are lost to follow-up (LTFU). This study explores factors potentially associated with retention in a large prospective study of Canadian medical cannabis patients, with the goal of reducing the probability that patients will be lost to follow-up in future cannabis research. METHODS: The Tilray Observational Patient Study (TOPS) was a multi-site, prospective study assessing the impact of medical cannabis over 6 months in a broad population of authorized Canadian cannabis patients. The study took place from 2016 to 19, and we conducted a series of exploratory analyses including a Kaplan-Meier survival analysis and logistic regressions to assess the potential association between study retention and variables including patient characteristics, cannabis and prescription drug use, quality of life, and the legalization of non-medical cannabis. RESULTS: Overall, 1011 participants were included in this analysis, contributing 287 patient-years of data. Retention was 728 (72%) at 3 months, and 419 (41.4%) at 6 months. Our analyses found significantly lower adjusted odds of retention following legalization (AOR 0.28, 95% CI 0.18-0.41), and in patients that used prescription opioids at baseline (AOR 0.62, 95% CI 0.46-0.85), while increased odds of retention were found in patients with a higher baseline psychological score (AOR 1.43, 95% CI 1.08-1.90) or that used anti-seizure medications at baseline (AOR 1.91, 95% CI 1.30-2.81). DISCUSSION: TOPS provided a unique opportunity to examine patient characteristics and other variables that may be associated with retention in prospective medical cannabis studies. Our findings highlight some of the challenges of conducting medical cannabis research at a time when patients have a multitude of cannabis access options, including legal adult dispensaries and a robust illicit market. High LTFU rates can impact the validity of studies, and potentially lead to misestimations of the harms and benefits of medical cannabis use. Despite being a multi-site prospective study, this was a convenience sample, thereby limiting the generalizability of these findings. Additionally, data regarding the use of cannabis was self-reported by patients, so is subject to potential recall bias. CONCLUSION: We found evidence that external policy changes that affect access to cannabis such as the legalization of non-medical adult use and patient characteristics associated with patient physical/psychological capacity can impact retention in prospective medical cannabis studies. Evidence-based strategies to reduce study burden on participants, such as minimizing in-person visits by providing digitized internet-based surveys and phone or telemedicine follow-up options as well as ensuring adequate participant compensation could improve retention. Additionally, policy-related changes aimed at improving access to medical cannabis, including increased cost-coverage and community-based distribution, could encourage patients to remain in the federal medical cannabis program and thereby reduce LTFU in associated studies.

Self-reported reductions in tobacco and nicotine use following medical cannabis initiation: Results from a cross-sectional survey of authorized medical cannabis patients in Canada.

BACKGROUND: Despite decades of campaigns aimed at reducing tobacco/nicotine (T/N) use and the development of many different T/N reduction and cessation strategies, the impacts on international public health remain significant. Some studies have found an association between medical and non-medical cannabis use and T/N use, although the evidence on whether cannabis/cannabinoids increase or decrease the odds of reducing or ceasing T/N use remain contradictory. This paper explores the self-reported use of cannabis and associated changes in T/N use among a Canadian medical cannabis patient population. METHODS: This study examines the impact of medical cannabis on T/N use by comparing self-reported patterns of use before and after the initiation of medical cannabis. Participants completed an online cross-sectional survey examining demographics, patterns of medical cannabis use, and the impact of medical cannabis on the use of T/N and other substances. The survey also included novel measures examining whether patients intended to use medical cannabis to reduce T/N use or had experience with other pharmacological or psychobehavioral T/N cessation strategies. We conducted a series of descriptive analyses and univariate and multivariate logistic regressions to explore the potential association between primary variables of interest and T/N reduction and cessation. RESULTS: In total, the study recruited 2102 individuals, of whom 650 were current or former T/N users. Following initiation of medical cannabis use 320 (49%) T/N users self-reported reductions in use, with 160 (24.6%) reporting no T/N use in the 30 days prior to the survey. Odds of T/N cessation were greater among those who were age 55 or older (Adjusted Odds Ratio [AOR] = 2.56, 95% Confidence Interval [CI] 1.53-4.26), or those who reported >25 T/N uses per day in the pre-period (AOR = 2.11, 95% CI 1.14-3.92). Specific intent to use medical cannabis to quit resulted in significantly greater odds of reducing T/N use (AOR = 2.79, 95% CI 1.49-5.22); however, involvement with traditional T/N cessation treatments (pharmacological or psychobehavioral) was negatively associated with T/N cessation (AOR 0.39, 95% CI 0.18-0.86). CONCLUSIONS: Results from this retrospective survey of medical cannabis users suggest that initiation of medical cannabis use was associated with self-reported reductions and/or cessation of T/N use in nearly half of study participants. In light of the significant morbidity, mortality, and health care costs related to T/N dependence, future research should further evaluate the potential of cannabis-based treatments to support efforts to reduce or cease T/N use.

Effects of Multi-Component Backgrounds of Volatile Plant Compounds on Moth Pheromone Perception.

The volatile plant compounds (VPC) alter pheromone perception by insects but mixture effects inside insect olfactory landscapes are poorly understood. We measured the activity of receptor neurons tuned to Z7-12Ac (Z7-ORN), a pheromone component, in the antenna and central neurons in male Agrotis ipsilon while exposed to simple or composite backgrounds of a panel of VPCs representative of the odorant variety encountered by a moth. Maps of activities were built using calcium imaging to visualize which areas in antennal lobes (AL) were affected by VPCs. We compared the VPC activity and their impact as backgrounds at antenna and AL levels, individually or in blends. At periphery, VPCs showed differences in their capacity to elicit Z7-ORN firing response that cannot be explained by differences in stimulus intensities because we adjusted concentrations according to vapor pressures. The AL neuronal network, which reformats the ORN input, did not improve pheromone salience. We postulate that the AL network evolved to increase sensitivity and to encode for fast changes of pheromone at some cost for signal extraction. Comparing blends to single compounds indicated that a blend shows the activity of its most active component. VPC salience seems to be more important than background complexity.

Cannabis Significantly Reduces the Use of Prescription Opioids and Improves Quality of Life in Authorized Patients: Results of a Large Prospective Study.

OBJECTIVES: This article presents findings from a large prospective examination of Canadian medical cannabis patients, with a focus on the impacts of cannabis on prescription opioid use and quality of life over a 6-month period. METHODS: The Tilray Observational Patient Study took place at 21 medical clinics throughout Canada. This analysis includes 1,145 patients who had at least one postbaseline visit, with follow-up at 1, 3, and 6 months. Instruments included a comprehensive cannabis use inventory, the World Health Organization Quality of Life Short Form (WHOQOL-BREF), and a detailed prescription drug questionnaire. RESULTS: Participants were 57.6% female, with a median age of 52 years. Baseline opioid use was reported by 28% of participants, dropping to 11% at 6 months. Daily opioid use went from 152 mg morphine milligram equivalent (MME) at baseline to 32.2 mg MME at 6 months, a 78% reduction in mean opioid dosage. Similar reductions were also seen in the other four primary prescription drug classes identified by participants, and statistically significant improvements were reported in all four domains of the WHOQOL-BREF. CONCLUSIONS: This study provides an individual-level perspective of cannabis substitution for opioids and other prescription drugs, as well as associated improvement in quality of life over 6 months. The high rate of cannabis use for chronic pain and the subsequent reductions in opioid use suggest that cannabis may play a harm reduction role in the opioid overdose crisis, potentially improving the quality of life of patients and overall public health.

Automatic tracking of free-flying insects using a cable-driven robot.

Flying insects have evolved to develop efficient strategies to navigate in natural environments. Yet, studying them experimentally is difficult because of their small size and high speed of motion. Consequently, previous studies were limited to tethered flights, hovering flights, or restricted flights within confined laboratory chambers. Here, we report the development of a cable-driven parallel robot, named lab-on-cables, for tracking and interacting with a free-flying insect. In this approach, cameras are mounted on cables, so as to move automatically with the insect. We designed a reactive controller that minimizes the online tracking error between the position of the flying insect, provided by an embedded stereo-vision system, and the position of the moving lab, computed from the cable lengths. We validated the lab-on-cables with Agrotis ipsilon moths (ca. 2 centimeters long) flying freely up to 3 meters per second. We further demonstrated, using prerecorded trajectories, the possibility to track other insects such as fruit flies or mosquitoes. The lab-on-cables is relevant to free-flight studies and may be used in combination with stimulus delivery to assess sensory modulation of flight behavior (e.g., pheromone-controlled anemotaxis in moths).

Reductions in alcohol use following medical cannabis initiation: results from a large cross-sectional survey of medical cannabis patients in Canada.

BACKGROUND: Evidence details how cannabis can influence the use of other psychoactive substances, including prescription medications, alcohol, tobacco and illicit drugs, but very little research has examined the factors associated with these changes in substance use patterns. This paper explores the self-reported use of cannabis as a substitute for alcohol among a Canadian medical cannabis patient population. METHODS: Data was derived from a survey of 2102 people enrolled in the Canadian medical cannabis program. We included 973 (44%) respondents who reported using alcohol on at least 10 occasions over a 12 month period prior to initiating medical cannabis, and then used retrospective data on the frequency and amount of alcohol use pre-and post medical cannabis initiation to determine which participant characteristics and other variables were associated with reductions and/or cessation of alcohol use. RESULTS: Overall, 419 (44%) participants reported decreases in alcohol usage frequency over 30 days, 323 (34%) decreased the number of standard drinks they had per week, and 76 (8%) reported no alcohol use at all in the 30 days prior to the survey. Being below 55 years of age and reporting higher rates of alcohol use in the pre-period were both associated with greater odds of reducing alcohol use, and an intention to use medical cannabis to reduce alcohol consumption was associated with significantly greater odds of both reducing and ceasing alcohol use altogether. CONCLUSIONS: Our findings suggest that medical cannabis initiation may be associated with self-reported reductions and cessation of alcohol use among medical cannabis patients. Since alcohol is the most prevalent recreational substance in North America, and its use results in significant rates of criminality, morbidity and mortality, these findings may result in improved health outcomes for medical cannabis patients, as well as overall improvements in public health and safety.

Light-Weight Portable Electroantennography Device as a Future Field-Based Tool for Applied Chemical Ecology.

Portable electroantennograms (pEAG) can further our understanding of odor plume dynamics and complement laboratory-based electroantennogram tools. pEAG's can help to address important questions such as the influence of plume structure on insect behavior, the active space of semiochemical-baited traps, and the impact of biotic and abiotic factors on this active space. Challenges associated with pEAGs include their miniaturization and sensitivity, confounding environmental odors, and processing of data. Here, we describe a pEAG built with modern engineering hardware and techniques that is portable in being both light in weight (516 g) and smaller (12 × 12 × 8 cm, volume 1152 cm3) than earlier models. It is able to incorporate insects of a range of sizes (4 to 30 mm antennal length), has wireless communication (communication range of 600 m urban, 10 km line of sight), a stand-alone power supply, and uses both antennae of the test insect. We report normalized antennal responses from Epiphyas postvittana in a dose response experiment where our pEAG compared favorably with traditional laboratory EAG equipment for this species. Dose-response comparisons between E. postvittana, Agrotis ipsilon, and Lymantria dispar dispar showed mean detection limits from a pheromone source dose of 100, 100, and 1 ng, respectively, for our pEAG. This pEAG should allow future real-time analysis of EAG responses in the field in research on how insects interact with odor plumes and the factors that influence the active space of semiochemical-baited traps.

Modulation of Sex Pheromone Discrimination by A UDP-Glycosyltransferase in Drosophila melanogaster.

The detection and processing of chemical stimuli involve coordinated neuronal networks that process sensory information. This allows animals, such as the model species Drosophila melanogaster, to detect food sources and to choose a potential mate. In peripheral olfactory tissues, several classes of proteins are acting to modulate the detection of chemosensory signals. This includes odorant-binding proteins together with odorant-degrading enzymes (ODEs). These enzymes, which primarily act to eliminate toxic compounds from the whole organism also modulate chemodetection. ODEs are thought to neutralize the stimulus molecule concurrently to its detection, avoiding receptor saturation thus allowing chemosensory neurons to respond to the next stimulus. Here, we show that one UDP-glycosyltransferase (UGT36E1) expressed in D. melanogaster antennal olfactory sensory neurons (OSNs) is involved in sex pheromone discrimination. UGT36E1 overexpression caused by an insertion mutation affected male behavioral ability to discriminate sex pheromones while it increased OSN electrophysiological activity to male pheromones. Reciprocally, the decreased expression of UGT36E1, controlled by an RNAi transgene, improved male ability to discriminate sex pheromones whereas it decreased electrophysiological activity in the relevant OSNs. When we combined the two genotypes (mutation and RNAi), we restored wild-type-like levels both for the behavioral discrimination and UGT36E1 expression. Taken together, our results strongly suggest that this UGT plays a pivotal role in Drosophila pheromonal detection.

Exploring ayahuasca-assisted therapy for addiction: A qualitative analysis of preliminary findings among an Indigenous community in Canada.

INTRODUCTION AND AIMS: A previous observational study of ayahuasca-assisted therapy demonstrated statistically significant reductions in self-reported problematic cocaine use among members of an Indigenous community in Canada. This paper aims to qualitatively explore the impact of ayahuasca-assisted therapy on addiction and other substance use-related outcomes and elucidate the lived experiences of participants. DESIGN AND METHODS: Qualitative interviews were conducted with 11 adult Indigenous participants of the ayahuasca-assisted 'Working with Addiction and Stress' ceremonial retreats (June-September 2011). Semi-structured interviews assessed experiences of participants following the retreats at 6-month follow up. Thematic analysis of interview transcripts was conducted. RESULTS: Narratives revealed that the retreats helped participants identify negative thought patterns and barriers related to their addiction in ways that differed from conventional therapies. All participants reported reductions in substance use and cravings; eight participants reported complete cessation of at least one substance at follow up. Increased connectedness with self, others and nature/spirit was described as a key element associated with reduced substance use and cravings. DISCUSSION AND CONCLUSIONS: This analysis expands upon prior quantitative results highlighting the therapeutic potential of ayahuasca-assisted therapy and provides important contextual insights into why ayahuasca-assisted therapy may have been beneficial for members of an Indigenous community seeking to address their problematic use of substances. Given limited efficacy of conventional treatments for resolving addiction issues, further research should investigate the role of ayahuasca and other psychedelic-assisted therapies in enhancing connectedness and other key factors that may improve well-being and reduce harmful substance use.

Adaptive integrate-and-fire model reproduces the dynamics of olfactory receptor neuron responses in a moth.

In order to understand how olfactory stimuli are encoded and processed in the brain, it is important to build a computational model for olfactory receptor neurons (ORNs). Here, we present a simple and reliable mathematical model of a moth ORN generating spikes. The model incorporates a simplified description of the chemical kinetics leading to olfactory receptor activation and action potential generation. We show that an adaptive spike threshold regulated by prior spike history is an effective mechanism for reproducing the typical phasic-tonic time course of ORN responses. Our model reproduces the response dynamics of individual neurons to a fluctuating stimulus that approximates odorant fluctuations in nature. The parameters of the spike threshold are essential for reproducing the response heterogeneity in ORNs. The model provides a valuable tool for efficient simulations of olfactory circuits.