Explore the vast range of titles available.

The human gut microbiome has emerged as a potential key factor involved in the manifestation of physical and mental health. Despite an explosion of cross-disciplinary interest in researching the gut microbiome, there remains to be a gold-standard method for operationalizing gut microbiome alpha diversity. Given researchers' interest in examining the relationships among gut microbiome alpha diversity and health-related outcomes of interest, a way of operationalizing the microbiome that yields a numeric value, which could be used in common statistical approaches, is needed. Thus, the current study aims to provide methodological guidance for how to operationalize microbiome alpha diversity. Findings suggest that alpha diversity of the human gut microbiome is comprised of two sub-constructs (richness and evenness), and we propose a step-by-step method of creating alpha diversity composite measures based on this key insight. Finally, we demonstrate that our empirically derived richness and evenness composite measures are significantly associated with health-related variables of interest (alcohol use, symptoms of depression) among a human clinical sample.

As cannabis legalization continues to spread across the United States, average Δ9-tetrahydrocannabinol concentrations in recreational products have significantly increased, and no prior study has evaluated effective treatments to reduce cannabis use among high potency cannabis users. Some research has found that the non-intoxicating cannabinoid cannabidiol reduces cannabis use and cannabis use disorder-related symptoms, such as affective disturbance and withdrawal. Results of these studies are promising but limited to synthetic or isolated forms of cannabidiol. Conduct a placebo-controlled randomized control trial comparing the effects of hemp-derived cannabidiol on reducing Δ9-tetrahydrocannabinol use in concentrate users with cannabis use disorder. Design. Double-blind, three-arm randomized placebo-controlled trial. Setting. University in the Denver-Boulder, CO, USA area. Study population. Community members who are heavy, stable cannabis concentrate users that meet criteria for at least moderate cannabis use disorder and are seeking to decrease or stop cannabis use. Data. Self-report demographics, substance use, and mental health characteristics, blood and urine based biomarkers and anthropometrics. Outcomes. Affective, physiological, and physical withdrawal symptoms, Δ9-tetrahydrocannabinol use. Analysis. Three-group ANOVAs and χ2 tests will be used to compare baseline variables between groups. Characteristics that differ between groups will be evaluated as potential covariates in subsequent analyses. A multilevel modeling framework will be used for primary outcome analysis to account for the repeated observations nested within participants over time. Pairwise post-hoc simple effects tests will be conducted to confirm patterns of differences. ClinicalTrials.gov NCT06107062.

The COVID-19 global pandemic is an unprecedented health threat for which behavior is critical to prevent spread and personal factors could contribute to decisions for protective action. The purpose of this study was to describe associations of COVID-19 related behaviors capturing a snapshot in time during the height of the first wave of the pandemic. We tested perceptions of likelihood and severity of infection, worry, and their associations with behavior. We further explored relationships by demographic characteristics, and tested main and interactive relationships between these characteristics and beliefs and protective behaviors. Using an online cross-sectional survey, U.S. adults (N = 795) reported their perceptions of likelihood and severity of, and worry about, contracting COVID-19 for self and others, and engagement in protective behaviors. In bivariate tests, all cognitive and affective beliefs were positively associated with hygiene behaviors, but only worry and personal and others’ severity were associated with greater likelihood of social distancing. Controlling for other beliefs and demographic factors, perceived personal severity remained associated with social distancing, and worry with hygiene behaviors. How people think and feel about risk could have implications for communicating information about this novel health threat and motivating action to mitigate its spread.

RationalePublished studies examining the effects of cannabis have largely utilized forms of cannabis that are not representative of the legal market products currently available.ObjectivesThe present study aimed to characterize naturalistic use of legal market flower and edible products by examining associations among blood cannabinoids and amount of THC consumed as well as physiological, cognitive, and subjective effects in users of edible and flower forms.MethodEighty-four participants who used cannabis at least 1 × /week (55 flower cannabis using participants; 29 edible cannabis using participants mean age = 31.95 years, 44% female) participated. At the experimental appointment in our mobile laboratory, participants completed a blood draw to assess plasma cannabinoids, measures of heart rate, subjective drug effects, and cognition both before and after ad libitum use of legal market flower or edible cannabis.ResultsAverage self-reported THC consumed was 15.97 mg (SD = 22.40) in edible users and 51.25 mg (SD = 45.23) in flower users. In the edible group, but not the flower group, strong correlations emerged between self-reported ad libitum THC consumed and plasma THC. Plasma THC was significantly higher after use of inhaled cannabis, but similar levels of plasma THC metabolites and similar levels of subjective intoxication and verbal memory impairment were observed in both flower and edible users.ConclusionsFindings support strong correlations among ad libitum THC consumed and THC plasma levels after edible cannabis use and suggest few differences in intoxication and impairment between edible and flower cannabis users after ad libitum use. This novel study provides important preliminary data on the pharmacology and effects of legal market edible cannabis.

Abstract Background and Hypothesis Individuals at clinical high risk for psychosis (CHR-p) are less fit than nonclinical peers and show hippocampal abnormalities that relate to clinical symptoms. Exercise generates hippocampal neurogenesis that may ameliorate these hippocampal abnormalities and related cognitive/clinical symptoms. This study examines the impact of exercise on deficits in fitness, cognitive deficits, attenuated psychotic symptoms, hippocampal volumes, and hippocampal connectivity in individuals at CHR-p. Study Design In a randomized controlled trial, 32 individuals at CHR-p participated in either an exercise (n = 17) or waitlist (no exercise) (n = 15) condition. All participants were sedentary at use and absent of current antipsychotic medication, psychosis diagnoses, or a substance use disorder. The participants completed a series of fitness, cognitive tasks, clinical assessments, and an MRI session preintervention and postintervention. The exercise intervention included a high-intensity interval exercise (80% of VO2max) with 1-minute high-intensity intervals (95% of VO2max) every 10 minutes) protocol twice a week over 3 months. Study Results The exercise intervention was well tolerated (83.78% retention; 81.25% completion). The exercising CHR-p group showed that improved fitness (pre/post-d = 0.53), increased in cognitive performance (pre/post-d = 0.49), decrease in positive symptoms (pre/post-d = 1.12) compared with the waitlist group. Exercising individuals showed stable hippocampal volumes; waitlist CHR-p individuals showed 3.57% decreased hippocampal subfield volume. Exercising individuals showed that increased exercise-related hippocampal connectivity compared to the waitlist individuals. Conclusions The exercise intervention had excellent adherence, and there were clear signs of mechanism engagement. Taken together, evidence suggests that high-intensity exercise can be a beneficial therapeutic tool in the psychosis risk period.

An age-related decline in endocannabinoid system (ECS) activity may contribute to conditions such as chronic pain and Alzheimer’s disease. Although cannabis is increasingly used by older adults to alleviate age-related conditions, it remains unclear how cannabinoids affect ECS activity across the lifespan. The present study assayed levels of seven endocannabinoids (AEA, 2-AG, DEA, LEA, PEA, SEA, and OEA) in a sample of adults ( N  = 142; younger 21–24 years, n  = 38; midlife 25–54, n  = 73; older 55–71, n  = 31) assayed before cannabis use (baseline [pre-use]) and ~ 1 h after flower or ~ 2 h after edible cannabis use. At baseline, older adults exhibited lower AEA and DEA than younger adults, and lower LEA than midlife adults. Acute cannabis use increased AEA, DEA, LEA, PEA, SEA, and OEA across all age groups (all p  < .001). 2-AG showed no increase. For AEA and DEA, increases were larger in older adults (Time×Age). These findings indicate broad endocannabinoid elevations after cannabis use regardless of age, alongside age-related differences at baseline and in acute responses.

Abstract Background Incentive interventions have gained popularity to motivate health behavior change, but some psychological theorists caution that they may have deleterious effects on factors that potentiate behavior maintenance. Importantly, no empirical study has tested whether incentives indeed have iatrogenic effects on key psychological constructs associated with health behavior change and maintenance. Purpose The study aims to explore the effects of monetary incentives on theoretically informed psychological constructs and fruit and vegetable consumption. Methods Individuals reporting insufficient fruit and vegetable consumption were randomly assigned to receive either daily monetary incentives, delayed monetary incentives, or no incentives for their fruit and vegetable consumption during a 3-week intervention period. Behavior engagement and psychological factors were measured at baseline, at the end of the intervention, and 2 weeks following the cessation of the intervention. Results Participants in the daily incentive condition demonstrated the greatest increase in self-reported consumption during the intervention and at the follow-up. Moreover, increases in consumption during the intervention period were associated with increases in attitudes and self-efficacy, which, in turn, predicted behavior maintenance at follow-up. Intrinsic motivation to consume fruits and vegetables increased over time across the entire sample but did not differ between groups. Conclusions Monetary incentives can alter health behavior engagement without decreasing intrinsic motivation or other relevant cognitive and motivational constructs. Further, although incentives may serve as a vehicle to initiate behavior change, increased experience with the behavior may then lead to enhancements in key psychological constructs that serve as mechanisms to potentiate behavior maintenance following the cessation of incentives. Trial Registration Number The trial was registered with the ClinicalTrials.gov database (NCT02594319) https://www.clinicaltrials.gov/ct2/show/NCT02594319.

Objectives The Timeline Followback (TLFB) was originally developed to assess alcohol consumption patterns (American Journal of Public Health, 86, 1996, 966) and has been increasingly modified for Web‐based use. Additionally, new modes of substance use administration have emerged, creating a need for an adaptable TLFB tool than can capture data such as cannabis product potency or prescription drug use. Our goal was to validate an online TLFB that reliably assesses a wide range of substances in greater detail. Methods Using a within‐subjects counterbalanced design, daily substance use data were collected from 50 college students over a 14‐day retrospective period using both the traditional in‐person TLFB and online TLFB (O‐TLFB). Results All substance use variables, including detailed measures of cannabis metrics, correlated significantly (r's ranged from .653 to .944, p < .001) between TLFB versions. Further, results demonstrated that both the online TLFB and in‐person TLFB demonstrated concurrent validity with both the Alcohol Use Disorders Identification Test (AUDIT) and Marijuana Dependence Scale (MDS). Conclusion Overall, the data suggest that this new O‐TLFB demonstrates strong reliability and delivers a versatile and secure tool for substance use assessment that is relevant to a variety of biomedical and psychological research contexts. Using a within‐subjects counterbalanced design, a new online Timeline Followback (TLFB) tool was validated against the in‐person TLFB and other measures of substance use. Substance use variables, including detailed measures of cannabis metrics, correlated significantly between TLFB versions, suggesting the new online TLFB is an accessible, versatile, and secure tool for substance use assessment that is relevant to a variety of biomedical and psychological research contexts.

Inflammation has been implicated as an underlying pathology in negative affect and sleep disruption. Cannabinoids like delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) have demonstrated anti-inflammatory properties. This study aimed to assess if cannabis use altered cytokine concentration and whether inflammatory status moderated the influence of 4 weeks of cannabis use on negative affect and sleep quality in anxious individuals. Participants with mild or greater anxiety ( = 147) were assigned to one of three cannabis chemovars (THC + CBD, THC, CBD), asked to consume their products for 4 weeks, and were compared to a group of participants with anxiety who did not use cannabis ( = 24). Measures of negative affect (Depression Anxiety and Stress Scale-21: DASS-21), sleep quality (Pittsburgh Sleep Quality Index: PSQI), and plasma cytokine concentrations were measured at Baseline and Week-4. Multilevel modeling assessed if there were group-dependent changes in cytokine concentrations over time, and whether baseline inflammation moderated the association between cannabis use and both negative affect and sleep quality. There were no group-dependent changes in cytokine concentrations throughout the study ( = 0.12). It was observed that baseline inflammatory state moderated the group-by-time relationship for DASS-21 ( < 0.001) and PSQI ( = 0.04). In both models, chemovars higher in CBD produced more consistent improvements, while THC-associated improvements varied by baseline inflammatory state. These novel findings suggest that baseline inflammatory status influences the relationship between cannabis use, negative affect, and sleep quality in people with anxiety.

Objective The present study aimed to examine the acute effects of legal-market cannabis on regular cannabis users’ subjective responses to exercise in a controlled laboratory environment. Background Given the stereotype that cannabis is associated with extreme sedentary behavior, there are concerns that cannabis legalization may exacerbate the US physical inactivity epidemic. However, despite these concerns, recent years have seen considerable public interest in the use of cannabis concurrently with exercise (e.g., running). Methods The present study compared participants’ experiences of exercise without cannabis to their experiences of exercise after acute ad libitum use of one of two commercially available cannabis flower products: a Δ9-tetrahydrocannabinol-dominant or a cannabidiol-dominant product. Participants ( N  = 42) were regular cannabis users between the ages of 21 and 39 years (mean = 30.81 years, standard deviation = 4.72 years). Results Although participants reported a more positive affect ( p  < 0.001), enjoyment ( p  < 0.001), and runner’s high symptoms ( p  < 0.001) during their cannabis (vs non-cannabis) exercise appointment, they also reported more exertion ( p  = 0.04). Pain levels were very low and did not differ between appointments ( p  = 0.45). Effects appeared to depend, in part, on cannabinoid content; there was a larger difference in enjoyment ( p  = 0.02), and a smaller difference in exertion ( p  = 0.02), between the cannabis and non-cannabis exercise appointments among participants in the cannabidiol (vs Δ9-tetrahydrocannabinol) condition. Conclusions To our knowledge, this is the first study to investigate the acute effects of commercially available cannabis on subjective responses to exercise in a laboratory environment. Our findings suggest that, among regular cannabis users who use cannabis in combination with exercise, cannabis use prior to exercise may lead to increases in both positive and negative aspects of the subjective exercise experience. Research using diverse samples, exercise modalities, and methodologies (e.g., placebo-controlled trials) is needed to establish the generalizability of these findings.