Ecological momentary assessment of working memory under conditions of simultaneous marijuana and tobacco use

The underrepresentation of racial/ethnic minorities in research on co-use of nicotine, alcohol, and/or cannabis via ecological momentary assessment methods: A narrative review

BACKGROUND

Co-use of nicotine, alcohol and/or cannabis is common among adults in the United States. Co-use may represent greater addiction severity than single substance use. Recent studies have examined the extent to which the frequency, order, simultaneity, motivations, and contextual factors associated with co-use differ from that of single use. Co-use has become prevalent among racial/ethnic minority individuals who exhibit distinct co-use patterns and related outcomes; however, most of these studies rely on cross-sectional or sparse longitudinal observations. Ecological momentary assessment (EMA) can illuminate such patterns and associations with time-varying contexts. This review summarizes EMA studies on co-use published from 2008 to 2023 involving racial/ethnic minority individuals and point to gaps. Our review addresses: 1) whether use of one substance leads to substitution or complementary use of another, 2) whether antecedents/contexts differ by co-use patterns and minority status, and 3) what consequences of co-use have been documented across co-use patterns or minority status.

METHODS

Search results yielded 465 articles, with 33 meeting inclusion criteria. We extracted study-level characteristics and synthesized the findings.

RESULTS

The findings largely focused on co-use patterns, categories of co-use, proximal antecedents and contexts, and consequences. Variations by minority status were rarely examined; few examined acute effects of unique experiences that may contribute to co-use among racial/ethnic minority adults.

CONCLUSIONS

The EMA literature on co-use is burgeoning in recent years and supports complementary hypothesis. More research to capture time-intensive data on experiences to contextualize the co-use among racial/ethnic minority groups with greater diversity in race/ethnicity is warranted.

Extended ambulatory assessment of executive function: within-person reliability of working memory and inhibitory control tasks

INTRODUCTION

Ambulatory assessment of executive function - particularly in the form working memory (WM) - is increasingly common. Few studies to date, however, have also incorporated ambulatory measures of inhibitory control. Critically, the extended within-person reliability of ambulatory tasks tapping each of these constructs has been largely overlooked.

METHOD

Participants (N = 283, Mage = 23.74 years, SD = 9.04) received notifications every 3 days (for 4 weeks) to undertake ambulatory assessment versions of the n-Back and Stop-Signal Tasks (SST) via the smartphone application CheckCog. Within-person reliability of these measures was explored.

RESULTS

Compliance ranged from 66% (for eight sessions) to 89% (for four sessions). Our results reveal significant changes in performance within the first two sessions for both the n-Back and SST, with performance remaining largely consistent across the remaining (two to eight) sessions. In terms of test-retest reliability, the ICC (C, 1) values ranged from .29 to .68 on the n-Back (with overall accuracy being .51) and .31-.73 on the SST (with stop-signal reaction time being .53).

CONCLUSION

The results of the current study contribute to the literature by demonstrating the reliability of brief measures of executive function - in the form of inhibitory control and WM - delivered using smartphones in participants' natural environments. Based on our findings, the CheckCog app reliability tracks baseline systematic changes in WM and response inhibition across multiple time points and for an extended period in healthy individuals.

The Combined Effects of Nicotine and Cannabis on Cortical Thickness Estimates in Adolescents and Emerging Adults

Early life substance use, including cannabis and nicotine, may result in deleterious effects on the maturation of brain tissue and gray matter cortical development. The current study employed linear regression models to investigate the main and interactive effects of past-year nicotine and cannabis use on gray matter cortical thickness estimates in 11 bilateral independent frontal cortical regions in 223 16-22-year-olds. As the frontal cortex develops throughout late adolescence and young adulthood, this period becomes crucial for studying the impact of substance use on brain structure. The distinct effects of nicotine and cannabis use status on cortical thickness were found bilaterally, as cannabis and nicotine users both had thinner cortices than non-users. Interactions between nicotine and cannabis were also observed, in which cannabis use was associated with thicker cortices for those with a history of nicotine and tobacco product (NTP) use in three left frontal regions. This study sheds light on the intricate relationship between substance use and brain structure, suggesting a potential modulation of cannabis' impact on cortical thickness by nicotine exposure, and emphasizing the need for further longitudinal research to characterize these interactions and their implications for brain health and development.

Development of Mobile Contingency Management for Cannabis Use Reduction

Many interventions for cannabis use disorder (CUD) are associated with decreases in frequency and quantity of use but fail to increase overall rates of sustained abstinence. It is currently unknown whether reductions in use (in the absence of sustained abstinence) result in clinically significant improvements in functioning. The objective of this study was to refine a mobile contingency management approach to reduce cannabis use to ultimately evaluate whether reductions in frequency and quantity of cannabis are related to improvements in functional and mental health status. Three cohorts of participants (n = 18 total, n = 10 women) were enrolled and completed 2 weeks of ecological momentary assessment (EMA) during a baseline ad lib cannabis use period, followed by a 6-week reduction period. Participants completed EMA assessments multiple times per day and were prompted to provide videotaped saliva cannabis testing 2-3 times daily. Data from participants who were at least 80% adherent to all EMA prompts were analyzed (13 out of 18). During the ad lib phase, participants were using cannabis on 94% of the days and reported using a mean of 1.42 grams daily. The intervention was a mobile application that participants used to record cannabis use by saliva tests to bioverify abstinence and participants completed electronic diaries to report their grams used. During the 6-week intervention phase, participants reported reducing their use days to 47% of the days with a reported mean of .61 grams daily. In the last cohort, at least 50% of the heavy users were able to reduce their cannabis use by at least 50%. The effect of cannabis reduction (versus abstinence) is largely unknown. Observations suggest that it is possible to develop a mobile intervention to reduce cannabis use among heavy users, and this paradigm can be utilized in future work to evaluate whether reductions in cannabis use among heavy users will result in improvements in functional and mental health status.

Associations of daily alcohol, cannabis, combustible tobacco, and e-cigarette use with same-day co-use and poly-use of the other substances

BACKGROUND

Young adults frequently use alcohol, cannabis, and tobacco together. Given the increased prevalence of e-cigarette use and recreational cannabis use, we investigated daily patterns of alcohol, cannabis, and tobacco use and distinguished combustible tobacco from e-cigarettes.

METHODS

Young adult college students (N=341) reporting past-month alcohol and cannabis use "at the same time so that their effects overlapped" completed two 28-day bursts of repeated daily surveys. Exposures were day- and person-level use of each substance. Outcomes were (1) same-day co-use of each remaining substance or (2) poly-use of the other substances.

RESULTS

Daily use of alcohol, cannabis, combustible cigarettes, and e-cigarettes increased the odds of same-day co-use of the other substances (except combustible tobacco with e-cigarettes) and each poly-use outcome. The influence of person-level substance use on daily substance use was less consistent. Only e-cigarette use increased the odds of daily alcohol use. Use of either tobacco product but not alcohol increased the odds of daily cannabis use. Person-level alcohol and cannabis use increased the odds of daily use of either tobacco product but use of one tobacco product was not associated with daily use of the other product.

CONCLUSIONS

These findings increase our understanding of emerging daily patterns of alcohol, cannabis, and tobacco co-use, and the impact of different tobacco products. Future work is needed to extend this research into non-college samples and people who use tobacco but do not use alcohol and cannabis simultaneously, and examine daily chronologies of multiple substances that could serve as dynamic markers of risk.

An ecological momentary assessment study to examine covariates and effects of concurrent and simultaneous use of electronic cigarettes and marijuana among college students

INTRODUCTION

The prevalence of concurrent and simultaneous use of e-cigarette and marijuana among college students is high. Yet, the literature was mainly based on cross-sectional surveys with emphasis on the smoking route. This is the first ecological momentary assessment (EMA) study that examined the vaping route of nicotine-marijuana co-use and the associated short-term psychological effects.

METHODS

This study recruited 686 college student e-cigarette users to participate in an on-line survey and 7-day EMA. Frequent marijuana users (247) - using marijuana weekly or daily - were compared with infrequent/non-users (439) on academic performance, e-cigarette use patterns, and dependence and respiratory symptoms. EMA data from the frequent users were used to study the association between marijuana vaping and e-cigarette consumption and the short-term psychological effects of e-cigarette and marijuana use.

RESULTS

The results show that e-cigarette users who frequently used marijuana tended to have lower academic performance, be involved in higher-risk use patterns, and have higher levels of e-cigarette dependence, marijuana problems, and respiratory symptoms, compared to infrequent/non-users. Marijuana vaping was associated with a higher level of e-cigarette consumption. E-cigarette use and marijuana use were both associated with higher levels of positive affect, physiological sensation, and craving for e-cigarettes. While marijuana use was linked to a lower level of negative affect, e-cigarette use did not have a significant effect. Further, none of the interaction effects between e-cigarette and marijuana use on psychological states were significant.

CONCLUSIONS

The results showed additive effects of e-cigarette and marijuana use although the hypothesized synergistic effects were not supported.

Impact of cannabis legalization in the United States on trends in cannabis use and daily cannabis use among individuals who smoke cigarettes

BACKGROUND

Cannabis legalization and increases in cannabis use are occurring rapidly in the United States (US). Cannabis and tobacco are often used together, but it is unclear whether cannabis legalization will differentially affect cannabis use among those using cigarettes. This study estimated changes from 2004 to 2017 in the prevalence of cannabis use and daily cannabis use by cigarette use status and examined whether state-level cannabis policy modified these trends.

METHODS

Public and restricted-use data from the 2004-2017 National Survey on Drug Use and Health were analyzed. Weighted logistic regressions were used to examine time trends in past-30-day cannabis use and daily caunabis use by cigarette use and cannabis law status from 2004 to 2017.

RESULTS

Cannabis use and daily use increased significantly among those with and without cigarette smoking. Cannabis use and daily cannabis use were consistently 2-10x more common throughout this time among those with, versus without, cigarette smoking. In 2017, cannabis use and daily cannabis use were substantially more common among individuals who use cigarettes, and even greater among those who live in states where cannabis was legal for medical or recreational (i.e., non-medical) use.

CONCLUSIONS

Cannabis use and daily cannabis use are increasing among US individuals who both smoke and do not smoke cigarettes. Cannabis and daily cannabis use are more common among those who smoke cigarettes and elevated even further among those residing in states that have legalized cannabis for recreational (i.e., non-medical) use. Tobacco control efforts should be adjusted to address increases in cannabis use among Americans who smoke cigarettes.

Simultaneous Alcohol and Marijuana Use Among Young Adults: A Scoping Review of Prevalence, Patterns, Psychosocial Correlates, and Consequences

BACKGROUND

Alcohol and marijuana are commonly used by young adults, and use of both substances, particularly at the same time, is prevalent among this population. Understanding the prevalence, patterns, correlates, and consequences of simultaneous alcohol and marijuana (SAM) use is important to inform interventions. However, this literature is complicated by myriad terms used to describe SAM use, including use with overlapping effects and same-day co-use.

OBJECTIVES

This scoping review identifies and describes the peer-reviewed literature focused on SAM use by young adults and distinguishes simultaneous use from same-day co-use of alcohol and marijuana. This review also provides a narrative summary of the prevalence of SAM use, patterns of SAM and other substance use, psychosocial correlates, and consequences of SAM use.

ELIGIBILITY CRITERIA

This review is limited to papers written in English and published in peer-reviewed journals between January 2000 and August 2021. It includes papers assessing simultaneous use or same-day co-use of alcohol and marijuana among young adults ages 18 to 30. Review papers, qualitative interviews, experimental lab studies, policy work, toxicology or medical reports, and papers focused on neurological outcomes are excluded.

SOURCES OF EVIDENCE

PubMed, PsycINFO, and Web of Science databases were searched. Databases were selected and the search strategy developed in consultation with an information specialist.

CHARTING METHODS

A data charting form was utilized to specify which information would be extracted from included papers. Eight categories of data were extracted: (1) research questions and hypotheses; (2) sample characteristics; (3) study procedures; (4) definition of SAM use; (5) prevalence of SAM use; (6) patterns of SAM and other substance use; (7) psychosocial correlates of SAM use; and (8) consequences of SAM use.

RESULTS

A total of 1,282 papers were identified through initial search terms. Through double-blind title/abstract screening and full-text review, the review was narrowed to 74 papers that met review inclusion criteria. Review of these papers demonstrated that SAM use was prevalent among young adults, particularly among those who reported heavier quantities and more frequent use of alcohol and marijuana. Enhancement-related motives for use were consistently positively associated with SAM use. SAM use was associated with greater perceived positive and negative consequences of alcohol and/or marijuana use. Inconsistencies in prevalence, patterns, correlates, and consequences were found between studies, which may be due to large variations in measurement of SAM use, populations studied, methodological design (e.g., cross-sectional vs. intensive longitudinal), and the covariates included in models.

CONCLUSIONS

The literature on simultaneous use and same-day co-use of alcohol and marijuana has expanded rapidly. Of the 74 included papers (61 on SAM use; 13 on same-day co-use), 60 papers (47 on SAM use; 13 on same-day co-use) were published within the last 5 years. Future research focusing on the ways in which SAM use confers acute risk, above and beyond the risks associated with separate consumption of alcohol and marijuana, is needed for understanding potential targets for intervention.

Smartphone-Based Neuropsychological Assessment in Parkinson's Disease: Feasibility, Validity, and Contextually Driven Variability in Cognition

OBJECTIVES

The prevalence of neurodegenerative disorders demands methods of accessible assessment that reliably captures cognition in daily life contexts. We investigated the feasibility of smartphone cognitive assessment in people with Parkinson's disease (PD), who may have cognitive impairment in addition to motor-related problems that limit attending in-person clinics. We examined how daily-life factors predicted smartphone cognitive performance and examined the convergent validity of smartphone assessment with traditional neuropsychological tests.

METHODS

Twenty-seven nondemented individuals with mild-moderate PD attended one in-lab session and responded to smartphone notifications over 10 days. The smartphone app queried participants 5x/day about their location, mood, alertness, exercise, and medication state and administered mobile games of working memory and executive function.

RESULTS

Response rate to prompts was high, demonstrating feasibility of the approach. Between-subject reliability was high on both cognitive games. Within-subject variability was higher for working memory than executive function. Strong convergent validity was seen between traditional tests and smartphone working memory but not executive function, reflecting the latter's ceiling effects. Participants performed better on mobile working memory tasks when at home and after recent exercise. Less self-reported daytime sleepiness and lower PD symptom burden predicted a stronger association between later time of day and higher smartphone test performance.

CONCLUSIONS

These findings support feasibility and validity of repeat smartphone assessments of cognition and provide preliminary evidence of the effects of context on cognitive variability in PD. Further development of this accessible assessment method could increase sensitivity and specificity regarding daily cognitive dysfunction for PD and other clinical populations.

The Effects of Nicotine and Cannabis Co-Use During Late Adolescence on White Matter Fiber Tract Microstructure

OBJECTIVE

Co-use of cannabis and nicotine and tobacco products (NTPs) in adolescence/young adulthood is common and associated with worse outcomes than the use of either substance in isolation. Despite this, little is known about the unique contributions of co-use to neurostructural microstructure during this neurodevelopmentally important period. This study sought to investigate the interactive effects of nicotine and cannabis co-use on white matter fiber tract microstructure in emerging adulthood.

METHOD

A total of 111 late adolescent (16-22 years old) nicotine (NTP; n = 55, all past-year cannabis users) and non-nicotine users (non-NTP; n = 56, 61% reporting cannabis use in the past year) completed demographic and clinical interviews and a neuroimaging session comprising anatomical and diffusion-weighted imaging scans. Group connectometry analysis identified white matter tracts significantly associated with the interaction between nicotine group and past-year cannabis use according to generalized fractional anisotropy (GFA).

RESULTS

Nicotine Group × Cannabis Use interactions were observed in the right and left cingulum and left fornix tracts (false discovery rate = 0.053), where greater cannabis use was associated with increased GFA in the cingulum and left fornix, but only when co-used with nicotine.

CONCLUSIONS

This report represents the first group connectometry analysis in late adolescent/young adult cannabis and/or NTP users. Results suggest that co-use of cannabis and NTPs results in a structurally distinct white matter phenotype as compared with cannabis use only, although to what extent this may change over time with more chronic nicotine and cannabis use remains to be examined in future work.

The Effects of Nicotine and Cannabis Co-Use During Late Adolescence on White Matter Fiber Tract Microstructure

OBJECTIVE

Co-use of cannabis and nicotine and tobacco products (NTPs) in adolescence/young adulthood is common and associated with worse outcomes than the use of either substance in isolation. Despite this, little is known about the unique contributions of co-use to neurostructural microstructure during this neurodevelopmentally important period. This study sought to investigate the interactive effects of nicotine and cannabis co-use on white matter fiber tract microstructure in emerging adulthood.

METHOD

A total of 111 late adolescent (16-22 years old) nicotine (NTP; n = 55, all past-year cannabis users) and non-nicotine users (non-NTP; n = 56, 61% reporting cannabis use in the past year) completed demographic and clinical interviews and a neuroimaging session comprising anatomical and diffusion-weighted imaging scans. Group connectometry analysis identified white matter tracts significantly associated with the interaction between nicotine group and past-year cannabis use according to generalized fractional anisotropy (GFA).

RESULTS

Nicotine Group × Cannabis Use interactions were observed in the right and left cingulum and left fornix tracts (false discovery rate = 0.053), where greater cannabis use was associated with increased GFA in the cingulum and left fornix, but only when co-used with nicotine.

CONCLUSIONS

This report represents the first group connectometry analysis in late adolescent/young adult cannabis and/or NTP users. Results suggest that co-use of cannabis and NTPs results in a structurally distinct white matter phenotype as compared with cannabis use only, although to what extent this may change over time with more chronic nicotine and cannabis use remains to be examined in future work.

Applications of technology in the assessment and treatment of cannabis use disorder

Cannabis use and Cannabis Use Disorder (CUD) have been increasing. There are no FDA approved medications and evidence-based psychotherapy is limited by insufficient providers, serving very few patients effectively. The lack of resources for prevention and treatment of CUD has resulted in a significant gap between the need for services and access to treatment. The creation of a scalable system to prevent, screen, refer and provide treatment for a chronic, relapsing diagnosis like CUD could be achieved through the application of technology. Many studies have utilized ecological momentary assessments (EMA) in treatment seeking and non-treatment seeking cannabis users. EMA allows for repeated, intensive, longitudinal data collection in vivo. EMA has been studied in cannabis use and its association with affect, craving, withdrawal, other substances, impulsivity, and interpersonal behaviors. EMA has the potential to serve as a valuable monitoring tool in prevention, screening, and treatment for CUD. Research has also focused on the development of internet and application-based treatments for CUD, including a currently available prescription digital therapeutic. Treatment options have expanded to more broadly incorporate telehealth as an option for CUD treatment with broad acceptance and change in regulation following the COVID-19 pandemic. While technology has limitations, including cost, privacy concerns, and issues with engagement, it will be a necessary medium to meet societal health needs as a consequence of an ever-changing cannabis regulatory landscape. Future work should focus on improving existing platforms while ethically incorporating other functions (e.g., sensors) to optimize a public and clinical health approach to CUD.

Acute effect of alcohol on working memory updating

AIMS

To examine the acute effects of alcohol on working memory (WM) updating, including potential variation across the ascending limb (AL) and descending limb (DL) of the blood alcohol concentration (BAC) time-course.

DESIGN

A two-session experiment in which participants were randomly assigned to one of three beverage conditions [alcohol (males: 0.80 g/kg; females: 0.72 g/kg), active placebo (0.04 g/kg) or non-alcohol control (tonic)] and one of two BAC limb testing conditions (AL and DL or DL-only) for the second session, yielding a 3 (beverage) × 2 (time-points tested) × 3 (time-point) mixed factorial design with repeated measures on the latter factor. One of the repeated assessments is 'missing by design' in the DL-only condition.

SETTING

A psychology laboratory at the University of Missouri campus in Columbia, MO, USA.

PARTICIPANTS

Two hundred thirty-one community-dwelling young adults (51% female; aged 21-34 years) recruited from Columbia, MO, USA, tested between 2011 and 2013.

MEASUREMENTS

Latent WM updating performance as indexed by shared variance in accuracy on three WM updating tasks (letter memory, keep track, spatial 2-back) at three time-points.

FINDINGS

Multi-group modeling of latent WM updating indicated that performance among participants who consumed placebo or control beverages improved during the second session at time-points corresponding to AL (∆ from baseline in latent mean ± standard error (SE) + 0.5 ± 0.01, P < 0.001) and DL (+ 0.08 ± 0.01, P < 0.001). Alcohol consumption did not impair WM updating (∆ from baseline in latent mean ± SE, at AL: + 0.01 ± 0.01, P = 0.56; at DL: + 0.05 ± 0.01, P < 0.001), but attenuated performance improvements (equality of latent means across beverage groups at AL or DL: Δχ2(1)  ≥ 7.53, P < 0.01).

CONCLUSIONS

Acute alcohol-induced impairment in working memory updating may be limited, but dampening of practice effects by alcohol could interfere with the completion of novel, unpracticed tasks.

The Society for Prevention Research 20 Years Later: a Summary of Training Needs

The Society for Prevention Research (SPR) aims to continually provide relevant professional development training opportunities to advance scientific investigation of ways to improve the health, well-being, and social and educational outcomes of individuals and communities. Our study, led by the Training Needs Assessment Task Force, designed a quantitative questionnaire informed by semistructured, qualitative interviews of 13 key prevention science informants. The questionnaire was deployed to all SPR members, of which 347 completed it. Questions about training topics were asked along 8 categories: (1) theory; (2) preventive interventions; (3) research methods, design, and evaluation; (4) teaching and mentoring; (5) practical and interpersonal skills; (6) communication; (7) project management; and (8) data analysis. Across all categories, respondents reported a high level of interest in receiving training: more than 80% were interested in training in data analytic methods; about 70% indicated interest in theory, preventive interventions, and research methods, design, and evaluation; about 65% were interested in at least 1 communication and project management topic; and 60% showed interest in at least 1 practical and interpersonal skills topic. Training-related interests varied across career level and race/ethnicity, with early-career individuals and people of color typically indicating the most interest. Participants were most likely to endorse self-initiated learning and webinars. SPR preconference training workshops were strongly endorsed for data analysis and preventive intervention topics. Recommendations from our study include a need for SPR to more strongly support self-initiated learning opportunities and continue preconference training programs, with special focuses in statistical methods and preventive interventions and regular assessment of members’ training preferences.

Compliance With Mobile Ecological Momentary Assessment of Self-Reported Health-Related Behaviors and Psychological Constructs in Adults: Systematic Review and Meta-analysis

Background

Mobile ecological momentary assessment (mEMA) permits real-time capture of self-reported participant behaviors and perceptual experiences. Reporting of mEMA protocols and compliance has been identified as problematic within systematic reviews of children, youth, and specific clinical populations of adults.

Objective

This study aimed to describe the use of mEMA for self-reported behaviors and psychological constructs, mEMA protocol and compliance reporting, and associations between key components of mEMA protocols and compliance in studies of nonclinical and clinical samples of adults.

Methods

In total, 9 electronic databases were searched (2006-2016) for observational studies reporting compliance to mEMA for health-related data from adults (>18 years) in nonclinical and clinical settings. Screening and data extraction were undertaken by independent reviewers, with discrepancies resolved by consensus. Narrative synthesis described participants, mEMA target, protocol, and compliance. Random effects meta-analysis explored factors associated with cohort compliance (monitoring duration, daily prompt frequency or schedule, device type, training, incentives, and burden score). Random effects analysis of variance (P≤.05) assessed differences between nonclinical and clinical data sets.

Results

Of the 168 eligible studies, 97/105 (57.7%) reported compliance in unique data sets (nonclinical=64/105 [61%], clinical=41/105 [39%]). The most common self-reported mEMA target was affect (primary target: 31/105, 29.5% data sets; secondary target: 50/105, 47.6% data sets). The median duration of the mEMA protocol was 7 days (nonclinical=7, clinical=12). Most protocols used a single time-based (random or interval) prompt type (69/105, 65.7%); median prompt frequency was 5 per day. The median number of items per prompt was similar for nonclinical (8) and clinical data sets (10). More than half of the data sets reported mEMA training (84/105, 80%) and provision of participant incentives (66/105, 62.9%). Less than half of the data sets reported number of prompts delivered (22/105, 21%), answered (43/105, 41%), criterion for valid mEMA data (37/105, 35.2%), or response latency (38/105, 36.2%). Meta-analysis (nonclinical=41, clinical=27) estimated an overall compliance of 81.9% (95% CI 79.1-84.4), with no significant difference between nonclinical and clinical data sets or estimates before or after data exclusions. Compliance was associated with prompts per day and items per prompt for nonclinical data sets. Although widespread heterogeneity existed across analysis (I²>90%), no compelling relationship was identified between key features of mEMA protocols representing burden and mEMA compliance.

Conclusions

In this 10-year sample of studies using the mEMA of self-reported health-related behaviors and psychological constructs in adult nonclinical and clinical populations, mEMA was applied across contexts and health conditions and to collect a range of health-related data. There was inconsistent reporting of compliance and key features within protocols, which limited the ability to confidently identify components of mEMA schedules likely to have a specific impact on compliance.

Perceived reward from using cigarettes with alcohol or cannabis and concurrent use: A smartphone-based daily diary study

INTRODUCTION

Smoking cigarettes under the influence of alcohol or cannabis is associated with perceived pleasure. However, it is unclear whether these changes in perceived reward impact the extent of concurrent use of cigarettes with alcohol or cannabis. The current study investigated if self-reported changes in perceived reward from concurrent use of cigarettes with alcohol or cannabis are related to the extent of concurrent use in real-world contexts using a smartphone-based Ecological Momentary Assessment (EMA) study.

METHODS

The sample included 126 diverse young adult smokers in the San Francisco Bay Area who reported current alcohol or cannabis use at baseline (M = 22.8 years, 50.8% male, 40.5% sexual minority, 39.7% Non-Hispanic White). Participants completed an online baseline survey and 30 days of smartphone-based daily EMA surveys of cigarette, alcohol, and cannabis use. The baseline assessed self-reported changes in perceived pleasure of smoking cigarettes while using alcohol or cannabis separately. EMA surveys included detailed questions about concurrent use (i.e., the extent of smoking while using another substance) covering the previous day. A total of 2,600 daily assessments were analyzed using mixed models.

RESULTS

Higher perceived pleasure from smoking cigarettes while drinking alcohol or using cannabis at baseline were both associated with a greater extent of concurrent use of cigarettes with alcohol (b = 0.140; SE = 0.066; t = 2.1; p = .035) and cannabis (b = 0.136; SE = 0.058; t = 2.4; p = .019) on a given day.

CONCLUSIONS

Results suggest that perceived reward from concurrently using cigarettes with alcohol or cannabis is associated with the extent of concurrent use. Findings can inform tailored smoking cessation interventions.

The Influence of Cannabis and Nicotine Co-use on Neuromaturation: A Systematic Review of Adolescent and Young Adult Studies

Accumulating evidence suggests that the use of cannabis and nicotine and tobacco-related products (NTPs) during the adolescent years has harmful effects on the developing brain. Yet, few studies have focused on the developing brain as it relates to the co-administration of cannabis and NTPs, despite the high prevalence rates of co-use in adolescence. This review aims to synthesize the existing literature on neurocognitive, structural neuroimaging, and functional neuroimaging outcomes associated with cannabis and NTP co-use. A systematic search of peer-reviewed articles resulted in a pool of 1107 articles. Inclusion criteria were 1) data-based study; 2) age range of 13 to 35 years or, for preclinical studies, nonadult subjects; 3) cannabis and NTP group jointly considered; and 4) neurocognitive, structural neuroimaging, or functional neuroimaging as an outcome measure. Twelve studies met inclusion criteria. Consistent with the literature, cannabis and nicotine were found to have independent effects on cognition. The available research on the co-use of cannabis and NTPs demonstrates a potential nicotine-related masking effect on cognitive deficits associated with cannabis use, yet there is little research on co-use and associations with neuroimaging indices. In neuroimaging studies, there is preliminary evidence for hippocampal volume differences in co-users and a lack of evidence for co-use differences related to nucleus accumbens activity during reward processing. Notably, no structural neuroimaging studies were found to examine the combined effects of nicotine and cannabis in adolescent-only populations. Further research, including longitudinal studies, is warranted to investigate the influence of cannabis and NTP co-use on maturation.

The effects of nicotine and cannabis co-use during adolescence and young adulthood on white matter cerebral blood flow estimates

RATIONALE

Co-use of cannabis and nicotine is common among adolescents/young adults and is associated with poorer psychological and physical outcomes, compared with single substance use. Little is known about the impact of co-use on the developing brain.

OBJECTIVES

Preliminary investigation of the effects of nicotine on white matter (WM) cerebral blood flow (CBF) in adolescents/young adults and its potential moderation by cannabis use.

METHODS

Adolescent/young adult (16-22 years old) nicotine and tobacco product users (NTP; N = 37) and non-nicotine users (non-NTP; N = 26) underwent a neuroimaging session comprised of anatomical, optimized pseudo-continuous arterial spin labeling, and diffusion tensor imaging scans. Groups were compared on whole-brain WM CBF estimates and their relation to past-year cannabis use. Follow-up analyses assessed correlations between identified CBF clusters and corresponding fractional anisotropy (FA) values.

RESULTS

Group by cannabis effects were observed in five clusters (voxel-wise alpha < 0.001, cluster-wise alpha < 0.05; ≥ 11 contiguous voxels): non-NTP exhibited positive correlations between CBF and cannabis use in all clusters, whereas no significant relationships were observed for NTP. Greater CBF extracted from one cluster (including portions of right superior longitudinal fasciculus) was associated with reduced FA for non-NTP group only.

CONCLUSIONS

This is the first investigation of WM health as indexed by CBF, and its association with FA, in adolescents/young adults with nicotine and/or cannabis use. Results suggest that cannabis use by itself may be related to increased CBF in WM fiber tracts demonstrating poorer structural intergrity, yet the occurrence of even infrequent NTP use (greater than once per month) appears to diminish this relationship.

Independent and Combined Effects of Nicotine or Chronic Tobacco Smoking and HIV on the Brain: A Review of Preclinical and Clinical Studies

Tobacco smoking is highly prevalent among HIV-infected individuals. Chronic smokers with HIV showed greater cognitive deficits and impulsivity, and had more psychopathological symptoms and greater neuroinflammation than HIV non-smokers or smokers without HIV infection. However, preclinical studies that evaluated the combined effects of HIV-infection and tobacco smoking are scare. The preclinical models typically used cell cultures or animal models that involved specific HIV viral proteins or the administration of nicotine to rodents. These preclinical models consistently demonstrated that nicotine had neuroprotective and anti-inflammatory effects, leading to cognitive enhancement. Although the major addictive ingredient in tobacco smoking is nicotine, chronic smoking does not lead to improved cognitive function in humans. Therefore, preclinical studies designed to unravel the interactive effects of chronic tobacco smoking and HIV infection are needed. In this review, we summarized the preclinical studies that demonstrated the neuroprotective effects of nicotine, the neurotoxic effects of the HIV viral proteins, and the scant literature on nicotine or tobacco smoke in HIV transgenic rat models. We also reviewed the clinical studies that evaluated the neurotoxic effects of tobacco smoking, HIV infection and their combined effects on the brain, including studies that evaluated the cognitive and behavioral assessments, as well as neuroimaging measures. Lastly, we compared the different approaches between preclinical and clinical studies, identified some gaps and proposed some future directions. Graphical abstract Independent and combined effects of HIV and tobacco/nicotine. Left top and bottom panels: Both clinical studies of HIV infected persons and preclinical studies using viral proteins in vitro or in vivo in animal models showed that HIV infection could lead to neurotoxicity and neuroinflammation. Right top and bottom panels: While clinical studies of tobacco smoking consistently showed deleterious effects of smoking, clinical and preclinical studies that used nicotine show mild cognitive enhancement, neuroprotective and possibly anti-inflammatory effects. In the developing brain, however, nicotine is neurotoxic. Middle overlapping panels: Clinical studies of persons with HIV who were smokers typically showed additive deleterious effects of HIV and tobacco smoking. However, in the preclinical studies, when nicotine was administered to the HIV-1 Tg rats, the neurotoxic effects of HIV were attenuated, but tobacco smoke worsened the inflammatory cascade.

Risk and Protective Factors for Alcohol Use Disorders Across the Lifespan

Purpose of Review

Losing and regaining control over alcohol intake varies as a function of individual-level predictors across the lifespan. Specifically, the interplay of protective and risk factors for losing and regaining control, particularly in real-life settings, is thus far poorly understood. Individual differences in cognition, affect, emotion regulation, social factors, and personality traits, together with individual differences in brain structure and function, and biological markers of stress exposure may have different effects on alcohol consumption in different age groups. We will review current evidence for age-specific effects for losing and regaining control over alcohol intake and propose a framework for investigation across age groups.

Recent Findings

We find evidence for differences in relative impact of psychosocial predictors of alcohol consumption as a function of age that varies by gender. There is theoretical reason to assume that predictors vary in the time course of their taking effect: While e.g., early trauma and personality traits may be conceptualized as more distant antecedents of alcohol consumption, cognition, affect and emotion regulation can be conceptualized as co-correlates, where variation over periods of months may go along with changes in alcohol consumption. At the same time, craving, current stressors, and priming events may serve as short-term or immediate causes of alcohol consumption.

Summary

We propose a combination of longitudinal age cohorts to (i) identify individual-level differences (using latent growth curve models) and profiles (using latent growth mixture models) of the psychosocial and biological variables of interest that predict regaining or losing control, and ambulatory assessments every 2 days, in order to (ii) investigate effects of triggers and risk factors on current alcohol consumption. This approach will allow us to characterize age-related differences in the interplay between these factors in real-life settings.

Digital health for assessment and intervention targeting tobacco and cannabis co-use

Purpose of review

This article aims to summarize current research on digital health for assessment and intervention targeting tobacco and cannabis co-use and to answer the following questions: Which digital tools have been used? Which populations have been targeted? And what are implications for future research?

Recent findings

Ecological Momentary Assessment (EMA) via text messages or interactive voice response calls has been used to capture co-use patterns within a time window or co-administration of both substances via blunts among young adults. Feasibility of multicomponent interventions targeting dual cessation of both substances among adult co-users with cannabis use disorder, delivered via smartphone apps, online, and computer modules has been demonstrated.

Summary

Digital tools, particularly those using EMAs and mobile sensors, should be expanded to assess co-use of emerging tobacco and cannabis products. Digital cessation interventions should be tailored to different groups of co-users and address specific mechanisms underlying different co-use patterns.

Mobile Assessment of Acute Effects of Marijuana on Cognitive Functioning in Young Adults: Observational Study

Background

Mobile assessment of the effects of acute marijuana on cognitive functioning in the natural environment would provide an ecologically valid measure of the impacts of marijuana use on daily functioning.

Objective

This study aimed to examine the association of reported acute subjective marijuana high (rated 0-10) with performance on 3 mobile cognitive tasks measuring visuospatial working memory (Flowers task), attentional bias to marijuana-related cues (marijuana Stroop), and information processing and psychomotor speed (digit symbol substitution task [DSST]). The effect of distraction as a moderator of the association between the rating of subjective marijuana high and task performance (ie, reaction time and number of correct responses) was explored.

Methods

Young adults (aged 18-25 years; 37/60, 62% female) who reported marijuana use at least twice per week were recruited through advertisements and a participant registry in Pittsburgh, Pennsylvania. Phone surveys and mobile cognitive tasks were delivered 3 times per day and were self-initiated when starting marijuana use. Completion of phone surveys triggered the delivery of cognitive tasks. Participants completed up to 30 days of daily data collection. Multilevel models examined associations between ratings of subjective marijuana high (rated 0-10) and performance on each cognitive task (reaction time and number of correct responses) and tested the number of distractions (rated 0-4) during the mobile task session as a moderator of the association between ratings of subjective marijuana high and task performance.

Results

Participants provided 2703 data points, representing 451 reports (451/2703, 16.7%) of marijuana use. Consistent with slight impairing effects of acute marijuana use, an increase in the average rating of subjective marijuana high was associated with slower average reaction time on all 3 tasks—Flowers (B=2.29; SE 0.86; P=.008), marijuana Stroop (B=2.74; SE 1.09; P=.01), and DSST (B=3.08; SE 1.41; P=.03)—and with fewer correct responses for Flowers (B=−0.03; SE 0.01; P=.01) and DSST (B=−0.18; SE 0.07; P=.01), but not marijuana Stroop (P=.45). Results for distraction as a moderator were statistically significant only for certain cognitive tasks and outcomes. Specifically, as hypothesized, a person’s average number of reported distractions moderated the association of the average rating of subjective marijuana high (over and above a session’s rating) with the reaction time for marijuana Stroop (B=−52.93; SE 19.38; P=.006) and DSST (B=−109.72; SE 42.50; P=.01) and the number of correct responses for marijuana Stroop (B=−0.22; SE 0.10; P=.02) and DSST (B=4.62; SE 1.81; P=.01).

Conclusions

Young adults’ performance on mobile cognitive tasks in the natural environment was associated with ratings of acute subjective marijuana high, consistent with slight decreases in cognitive functioning. Monitoring cognitive functioning in real time in the natural environment holds promise for providing immediate feedback to guide personal decision making.

Digital assessment of working memory and processing speed in everyday life: Feasibility, validation, and lessons-learned

OBJECTIVES

Cognitive functioning is often impaired in mental and neurological conditions and might fluctuate throughout the day. An existing experience-sampling tool was upgraded to assess individual's cognition in everyday life. The objectives were to test the feasibility and validity of two momentary cognition tasks.

METHODS

The momentary Visuospatial Working Memory Task (mVSWMT) and momentary Digit Symbol Substitution Task (mDSST) were add-ons to an experience sampling method (ESM) smartphone app. Healthy adults (n = 49) between 19 and 73 years of age performed the tasks within an ESM questionnaire 8 times a day, over 6 consecutive days. Feasibility was determined through completion rate and participant experience. Validity was assessed through contextualization of cognitive performance within intrapersonal and situational factors in everyday life.

FINDINGS

Participants experienced the tasks as pleasant, felt motivated, and the completion rate was high (71%). Social context, age, and distraction influenced cognitive performance in everyday life. The mVSWMT was too difficult as only 37% of recalls were correct and thus requires adjustments (i.e. fixed time between encoding and recall; more trials per moment). The mDSST speed outcome seems the most sensitive outcome measure to capture between- and within-person variance.

CONCLUSIONS

Short momentary cognition tasks for repeated assessment are feasible and hold promise, but more research is needed to improve validity and applicability in different samples. Recommendations for teams engaging in the field include matching task design with traditional neuropsychological tests and involving a multidisciplinary team as well as users. Special attention for individual needs can improve motivation and prevent frustration. Finally, tests should be attractive and competitive to stimulate engagement, but still reflect actual cognitive functioning.

Mobile Sensing in Substance Use Research: A Scoping Review

Background: Addictive disorders and substance use are significant health challenges worldwide, and relapse is a core component of addictive disorders. The dynamics surrounding relapse and especially the immediate period before it occurs is only partly understood, much due to difficulties collecting reliable and sufficient data from this narrow period. Mobile sensing has been an important way to improve data quality and enhance predictive capabilities for symptom worsening within physical and mental health care, but is less developed within substance use research. Methodology: This scoping review aimed to reviewing the currently available research on mobile sensing of substance use and relapse in substance use disorders. The search was conducted in January 2019 using PubMed and Web of Science. Results: Six articles were identified, all concerning subjects using alcohol. In the studies a range of mobile sensors and derived aggregated features were employed. Data collected through mobile sensing were predominantly used to make dichotomous inference on ongoing substance use or not and in some cases on the quantity of substance intake. Only one of the identified studies predicted later substance use. A range of statistical machine learning techniques was employed. Conclusions: The research on mobile sensing in this field remains scarce. The issues requiring further attention include more research on clinical populations in naturalistic settings, use of a priori knowledge in statistical modeling, focus on prediction of substance use rather than purely identification, and finally research on other substances than alcohol.

Is Cannabis Use Associated With Increased Risk of Cigarette Smoking Initiation, Persistence, and Relapse? Longitudinal Data From a Representative Sample of US Adults

OBJECTIVE

The current study prospectively investigated the relationship between cannabis use and cigarette smoking initiation, persistence, and relapse during a 3-year period among adults in the United States.

METHODS

Analyses included respondents who completed Waves 1 (2001-2002) and 2 (2004-2005) of the National Epidemiologic Survey on Alcohol and Related Conditions and responded to questions about cannabis use and smoking status (n = 34,639). Multivariable logistic regression models were used to calculate the odds of cigarette use at Wave 2 among Wave 1 daily smokers, nondaily smokers, former smokers, and nonsmokers by Wave 1 cannabis use.

RESULTS

In unadjusted analyses, Wave 1 cannabis use was associated with increased odds of Wave 2 daily and nondaily smoking for Wave 1 nonsmokers (daily OR = 2.90; 95% CI, 2.10-4.00; nondaily OR = 4.45; 95% CI, 3.97-5.00) and Wave 2 relapse to daily and nondaily smoking for Wave 1 former smokers (daily OR = 4.18, 95% CI, 3.01-5.81; nondaily OR = 5.24; 95% CI, 3.74-7.34). Wave 1 cannabis use was associated with decreased odds of Wave 2 smoking cessation for Wave 1 daily cigarette smokers (OR = 0.57; 95% CI, 0.51-0.64). The associations remained significant for daily smoking initiation (OR = 1.43; 95% CI, 1.06-1.93), daily smoking relapse (OR = 1.47; 95% CI, 1.00-2.16), and smoking cessation (OR = 0.77; 95% CI, 0.69-0.87) after adjusting for demographics and psychiatric disorders. Associations remained significant for nondaily smoking initiation (OR = 1.85; 95% CI, 1.59-2.16) and nondaily smoking relapse (OR = 1.63; 95% CI, 1.05-2.54) after adjusting for these covariates as well as for alcohol and substance use disorders.

CONCLUSIONS

Cannabis use was associated with increased initiation of, persistence of, and relapse to cigarette smoking. Additional attention to cannabis use in tobacco control efforts and in clinical settings aimed at reducing cigarette smoking and smoking-related negative consequences may be warranted.

Cigarette smoking quit ratios among adults in the USA with cannabis use and cannabis use disorders, 2002-2016

BACKGROUND

The prevalence of cigarette smoking is nearly three times higher among persons who use cannabis and have cannabis use disorders (CUDs), relative to those who do not. The current study examined cigarette quit ratios from 2002 to 2016 among US adults with and without cannabis use and CUDs.

METHODS

The current study analysed US adults aged 18 years and older from the National Survey on Drug Use and Health, an annual cross-sectional study. Quit ratios (ie, proportion of former smokers among ever-smokers) were calculated annually from 2002 to 2016. Time trends in quit ratios by cannabis use/CUDs were tested using logistic regression.

RESULTS

In 2016, the quit ratios for people with any cannabis use (23%) and CUDs (15%) were less than half the quit ratios of those without cannabis use and CUDs (51% and 48%, respectively). After controlling for demographics and substance use disorders, the quit ratio did not change from 2002 to 2016 among persons with CUD, though it non-linearly increased among persons with cannabis use, without cannabis use and without CUDs. Quit ratios increased more rapidly among those who reported past-month cannabis use compared with those without past-month cannabis use.

CONCLUSIONS

Cigarette smoking quit ratios remain dramatically lower among people who use cannabis and have CUDs and quit ratios did not change significantly from 2002 to 2016 among those with CUDs. Public health and clinical attention are needed to increase quit ratios and reduce harmful cigarette smoking consequences for persons with cannabis use and CUDs.

Compliance with ecological momentary assessment protocols in substance users: a meta-analysis

BACKGROUND AND AIMS

While there are considerable benefits to Ecological Momentary Assessment (EMA), poor compliance with assessment protocols has been identified as a limitation, particularly in substance users. Our aim was to identify the pooled compliance rate of EMA studies in substance users and examine variables that may influence compliance with EMA protocols, such as the length and frequency of assessments.

DESIGN

A meta-analysis and meta-regression of all possible studies (randomized controlled trials and longitudinal) which incorporated EMA protocols, examining substance use.

SETTING

Studies took place from 1998 to 2017, in numerous countries world-wide.

PARTICIPANTS

One hundred and twenty-six studies were identified, contributing a total of 19 431 participants (52.32% male, mean age = 28.86).

MEASUREMENTS

Compliance data, the proportion of responses to the study protocol, were extracted from each study alongside prompt frequency, total length of assessment period, substance use population and device used to administer EMA prompts.

FINDINGS

The pooled compliance rate across all studies was 75.06% [95% confidence interval (CI) = 72.37%, 77.65%]. There was no evidence that compliance rates were significantly associated with prompt frequency [Q(3) = 7.35, P = 0.061], length of assessment period [Q(2) = 2.40, P = 0.301], substance type [Q(3) = 6.30, P = 0.098] or device administration [Q(4) = 4.28, P = 0.369]. However, dependent samples (69.80%) had lower compliance rates than non-dependent samples [76.02%; Q(1) = 4.13, P = 0.042].

CONCLUSIONS

The pooled compliance rate for Ecological Momentary Assessment studies in substance-using populations from 1998 to 2017 was lower than the recommended rate of 80%, and was not associated with frequency or duration of assessments.

Trends in cannabis use disorder by cigarette smoking status in the United States, 2002-2016

BACKGROUND

Cannabis use is on the rise in the United States (US) and is disproportionately common among cigarette smokers. Cannabis use disorder (CUD) occurs among a small subset of cannabis users and may impact cigarette use. The objective of this study was to estimate trends in the prevalence of CUD among daily, non-daily, former, and never cigarette smokers from 2002 to 2016.

METHODS

Data were drawn from cross-sectional, nationally representative samples of individuals ages 12 and older in the US that were collected annually. The prevalence of past 12-month CUD was estimated each year from 2002 to 2016 among daily, non-daily, former, and never cigarette smokers (total analytic N = 837,326).

RESULTS

Overall, the prevalence of CUD decreased from 2002 to 2016. Yet, trends differed by cigarette smoking status. Adjusting for demographics, the prevalence of CUD increased significantly among non-daily smokers (aOR = 1.02; 95% CI = 1.01-1.03) from 2002 to 2016 and did not change among daily, former, or never smokers. CUD was significantly more common among non-daily (4.32%) and daily cigarette smokers (2.92%) compared with former (0.99%) and never smokers (1.11%) in 2016. Approximately one in five (18.11%-22.87%) youth ages 12-17 who smoke cigarettes met criteria for CUD in 2016, compared with approximately 2% of non-smoking youth.

CONCLUSIONS

Despite downward trends in CUD observed at the general population level, the prevalence of CUD significantly increased among non-daily cigarette smokers from 2002 to 2016. In the US, CUD remains significantly higher among cigarette smokers relative to non-cigarette smokers.

Alcohol Use in Adolescence and Later Working Memory: Findings From a Large Population-Based Birth Cohort

Aims

The study aimed to examine the association between adolescent alcohol use and working memory (WM) using a large population sample.

Methods

Data from the Avon Longitudinal Study of Parents and Children were used to investigate the association between alcohol use at age 15 years and WM 3 years later, assessed using the N-back task (N ~ 3300). A three-category ordinal variable captured mutually exclusive alcohol groupings ranging in order of severity (i.e. low alcohol users, frequent drinkers and frequent/binge drinkers). Differential dropout was accounted for using multiple imputation and inverse probability weighting. Adjustment was made for potential confounders.

Results

There was evidence of an association between frequent/binge drinking (compared to the low alcohol group) and poorer performance on the 3-back task after adjusting for sociodemographic confounding variables, WM at age 11 years, and experience of a head injury/unconsciousness before age 11 years (β = −0.23, 95% CI = −0.37 to −0.09, P = 0.001). However, this association was attenuated (β = −0.12, 95% CI = −0.27 to 0.03, P = 0.11) when further adjusted for baseline measures of weekly cigarette tobacco and cannabis use. Weaker associations were found for the less demanding 2-back task. We found no evidence to suggest frequent drinking was associated with performance on either task.

Conclusions

We found weak evidence of an association between sustained heavy alcohol use in mid-adolescence and impaired WM 3 years later. Although we cannot fully rule out the possibility of reverse causation, several potential confounding variables were included to address the directionality of the relationship between WM and alcohol use problems.

Combining ecological momentary assessment with objective, ambulatory measures of behavior and physiology in substance-use research

Whereas substance-use researchers have long combined self-report with objective measures of behavior and physiology inside the laboratory, developments in mobile/wearable electronic technology are increasingly allowing for the collection of both subjective and objective information in participants' daily lives. For self-report, ecological momentary assessment (EMA), as implemented on contemporary smartphones or personal digital assistants, can provide researchers with near-real-time information on participants' behavior and mood in their natural environments. Data from portable/wearable electronic sensors measuring participants' internal and external environments can be combined with EMA (e.g., by timestamps recorded on questionnaires) to provide objective information useful in determining the momentary context of behavior and mood and/or validating participants' self-reports. Here, we review three objective ambulatory monitoring techniques that have been combined with EMA, with a focus on detecting drug use and/or measuring the behavioral or physiological correlates of mental events (i.e., emotions, cognitions): (1) collection and processing of biological samples in the field to measure drug use or participants' physiological activity (e.g., hypothalamic-pituitary-adrenal axis activity); (2) global positioning system (GPS) location information to link environmental characteristics (disorder/disadvantage, retail drug outlets) to drug use and affect; (3) ambulatory electronic physiological monitoring (e.g., electrocardiography) to detect drug use and mental events, as advances in machine learning algorithms make it possible to distinguish target changes from confounds (e.g., physical activity). Finally, we consider several other mobile/wearable technologies that hold promise to be combined with EMA, as well as potential challenges faced by researchers working with multiple mobile/wearable technologies simultaneously in the field.

A Practical Guide to Analyzing Time-Varying Associations between Physical Activity and Affect Using Multilevel Modeling

There is growing interest in within-person associations of objectively measured physical and physiological variables with psychological states in daily life. Here we provide a practical guide with SAS code of multilevel modeling for analyzing physical activity data obtained by accelerometer and self-report data from intensive and repeated measures using ecological momentary assessments (EMA). We review previous applications of EMA in research and clinical settings and the analytical tools that are useful for EMA research. We exemplify the analyses of EMA data with cases on physical activity data and affect and discuss the future challenges in the field.

Can an app help identify psychomotor function impairments during drinking occasions in the real world? A mixed-method pilot study

BACKGROUND

Being able to measure the acute effects of alcohol consumption on psychomotor functions in natural settings could be useful in injury prevention interventions. This study examined the feasibility and acceptability of collecting app-based measures of information processing, working memory, and gait stability during times of typical alcohol consumption among young adults.

METHODS

Ten young adults (aged 21-26) with hazardous drinking completed a baseline assessment and ecological momentary assessments (EMA) on 4 consecutive Fridays and Saturdays, every hour from 8 pm to 12 am. EMA assessed alcohol consumption and perceived intoxication, followed by a digit symbol substitution task (DSST), a visuospatial working memory task (VSWMT), and a 5-step tandem gait task (TGT). Exit interviews probed user experiences. Multilevel models explored relationships between estimated blood alcohol concentration (eBAC; mg/dL) and DSST and VSWMT performance.

RESULTS

Participants completed 32% of EMA. Higher rates of noninitiation occurred later in the evening and over time. In multilevel models, higher eBAC was associated with lower DSST scores. Eight out of 10 individuals had at least 1 drinking occasion when they did not perceive any intoxication. Lower DSST scores would identify impairment in 45% of these occasions. Exit interviews indicated that adding real-time feedback on task performance could increase awareness of alcohol effects.

CONCLUSIONS

Collecting app-based psychomotor performance data from young adults during drinking occasions is feasible and acceptable, but strategies to reduce barriers to task initiation are needed. Mobile DSST is sensitive to eBAC levels and could identify occasions when an individual may not perceive impairments.

Co-use of cannabis, tobacco, and alcohol during adolescence: policy and regulatory implications

Legislative reforms have legalized use of cannabis for medical and recreational purposes. Efforts to evaluate the public health impact of these changes have predominantly focused on determining whether liberalizing cannabis policies has increased cannabis use patterns. Co-use of cannabis and other licit substances, namely tobacco and alcohol, is common during the developmental period of adolescence, which is generally characterized by an increase in risk-taking and novelty-seeking. However, limited research has sought to evaluate the potential implications of reforms to medical and recreational cannabis laws on concurrent and simultaneous use of cannabis, tobacco, and alcohol during adolescence. The current report reviews the extant literature detailing the prevalence and outcomes associated with concurrent and simultaneous cannabis-tobacco and cannabis-alcohol use, including recent work that has examined how concurrent and simultaneous use may be influenced by cannabis reform. This review details how the cannabis landscape and cannabis retail marketplace have evolved and briefly summarizes the corresponding policy and regulatory challenges that have emerged. The report concludes with a focused cannabis co-use research agenda that adopts different strategies including behavioural economic, self-administration, and survey research methods.

Marijuana use among US tobacco users: Findings from wave 1 of the population assessment of tobacco health (PATH) study

BACKGROUND

With an increase in marijuana use among adults in the United States (US), understanding the potential impact of marijuana use on tobacco use and associated behavioral and health consequences, including respiratory conditions, is necessary.

METHOD

Survey responses from Wave 1 of the nationally representative Population Assessment of Tobacco and Health (PATH) Study were used to assess tobacco use and marijuana use among non-current tobacco users (n = 17,952) and current established tobacco-users classified as: cigarette only users (n = 8689), e-cigarette only users (n = 437), cigar only (traditional, cigarillo, or filtered) users (n = 706), hookah only users (n = 461), smokeless tobacco only users (n = 971), cigarette + e-cigarette users (n = 709), and users of multiple tobacco products (n = 2314).

RESULTS

When compared to non-current tobacco users, each tobacco user group except smokeless only users had higher odds (odds ratios ranging from 3.86-8.07) of reporting current marijuana use. Among current tobacco users, higher levels of tobacco dependence did not explain the relationship between tobacco use and marijuana use. Additionally, concurrent marijuana use was associated with lower odds of attempts to quit tobacco (OR = 0.86, 95% CI = 0.79, 0.94, p < 0.001) and a higher probability (OR = 1.35, 95CI = 1.21, 1.51, p < 0.01) of reporting a history of respiratory disease.

CONCLUSIONS

The association between concurrent use of tobacco and marijuana and higher tobacco dependence and lower rates of quit attempts suggests the potential for sustained tobacco use and deleterious health effects. Further, marijuana use may represent an additive risk for respiratory harm among concurrent users of tobacco and marijuana.

Concurrent and Simultaneous Use of Cannabis and Tobacco and Its Relationship with Academic Achievement amongst University Students

The combined use of cannabis and tobacco is frequent in Europe. Few studies have nonetheless explored this pattern of consumption and its relationship with academic achievement in Spanish population. The aim of the present study was to analyze (1) the frequency of four patterns of polydrug use the last year (non-dual users of cannabis and tobacco; concurrent users: cannabis and tobacco separately; simultaneous users: tobacco in cannabis "joints"; simultaneous users: tobacco in cannabis joints alongside alcohol) by gender and age; (2) grade point average (GPA) by gender and age; (3) the association between the frequency of the four patterns of use and the GPA amongst a sample of 477 Spanish university students. The use of cannabis and tobacco (concurrent and simultaneous) and GPA were assessed by means of self-reported questionnaires. Statistically significant differences were found for the GPA with respect to gender. The GPA by the non-dual users of cannabis and tobacco was significantly higher than the GPA corresponding to the concurrent and simultaneous users. The combined use of cannabis and tobacco, regardless of the type of use (concurrent or simultaneous), is moderately related to poor academic achievement amongst university students.

Adolescent brain cognitive development (ABCD) study: Overview of substance use assessment methods

One of the objectives of the Adolescent Brain Cognitive Development (ABCD) Study (https://abcdstudy.org/) is to establish a national longitudinal cohort of 9 and 10 year olds that will be followed for 10 years in order to prospectively study the risk and protective factors influencing substance use and its consequences, examine the impact of substance use on neurocognitive, health and psychosocial outcomes, and to understand the relationship between substance use and psychopathology. This article provides an overview of the ABCD Study Substance Use Workgroup, provides the goals for the workgroup, rationale for the substance use battery, and includes details on the substance use module methods and measurement tools used during baseline, 6-month and 1-year follow-up assessment time-points. Prospective, longitudinal assessment of these substance use domains over a period of ten years in a nationwide sample of youth presents an unprecedented opportunity to further understand the timing and interactive relationships between substance use and neurocognitive, health, and psychopathology outcomes in youth living in the United States.

Mobile Phone Ownership Is Not a Serious Barrier to Participation in Studies: Descriptive Study

BACKGROUND

Rather than providing participants with study-specific data collection devices, their personal mobile phones are increasingly being used as a means for collecting geolocation and ecological momentary assessment (EMA) data in public health research.

OBJECTIVE

The purpose of this study was to (1) describe the sociodemographic characteristics of respondents to an online survey screener assessing eligibility to participate in a mixed methods study collecting geolocation and EMA data via the participants' personal mobile phones, and (2) examine how eligibility criteria requiring mobile phone ownership and an unlimited text messaging plan affected participant inclusion.

METHODS

Adult (≥18 years) daily smokers were recruited via public advertisements, free weekly newspapers, printed flyers, and word of mouth. An online survey screener was used as the initial method of determining eligibility for study participation. The survey screened for twenty-eight inclusion criteria grouped into three categories, which included (1) cell phone use, (2) tobacco use, and (3) additional criteria.

RESULTS

A total of 1003 individuals completed the online screener. Respondents were predominantly African American (605/1003, 60.3%) (60.4%), male (514/1003, 51.3%), and had a median age of 35 years (IQR 26-50). Nearly 50% (496/1003, 49.5%) were unemployed. Most smoked menthol cigarettes (699/1003, 69.7%), and had a median smoking history of 11 years (IQR 5-21). The majority owned a mobile phone (739/1003, 73.7%), could install apps (86.8%), used their mobile phone daily (89.5%), and had an unlimited text messaging plan (871/1003, 86.8%). Of those who completed the online screener, 302 were eligible to participate in the study; 163 were eligible after rescreening, and 117 were enrolled in the study. Compared to employed individuals, a significantly greater proportion of those who were unemployed were ineligible for the study based on mobile phone inclusion criteria (P<.001); yet, 46.4% (333/717) of the individuals who were unemployed met all mobile phone inclusion criteria.

CONCLUSIONS

Inclusion criteria requiring participants to use their personal mobile phones for data collection was not a major barrier to study participation for most respondents who completed the online screener, including those who were unemployed.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02261363; https://clinicaltrials.gov/ct2/show/NCT02261363 (Archived by WebCite at http://www.webcitation.org/6wOmDluSt).

Trends in Daily Cannabis Use Among Cigarette Smokers: United States, 2002-2014

OBJECTIVES

To estimate changes in the prevalence of daily cannabis use among current, former, and never cigarette smokers from 2002 to 2014 in the United States.

METHODS

The National Survey on Drug Use and Health is a nationally representative cross-sectional study conducted annually among persons aged 12 years and older in the United States.

RESULTS

Daily cannabis use occurs nearly exclusively among nondaily and daily cigarette smokers compared with former and never smokers (8.03%, 9.01%, 2.79%, 1.05%, respectively). Daily cannabis use increased over the past decade among both nondaily (8.03% [2014] vs 2.85% [2002]; linear trend P < .001) and daily smokers (9.01% [2014]; 4.92% [2002]; linear trend P < .001). Daily cannabis use increased most rapidly among former cigarette smokers (2.79% [2014] vs 0.98% [2002]; linear trend P < .001).

CONCLUSIONS

Daily cannabis use occurs predominantly among cigarette smokers in the United States. Daily cannabis use increased among current, former, and never smokers over the past decade, with particularly rapid increases among youth and female cigarette smokers. Future research is needed to monitor the observed increase in daily cannabis use, especially among youths and adults who smoke cigarettes.

Acute memory and psychotomimetic effects of cannabis and tobacco both 'joint' and individually: a placebo-controlled trial

BACKGROUND

Cannabis and tobacco have contrasting cognitive effects. Smoking cannabis with tobacco is prevalent in many countries and although this may well influence cognitive and mental health outcomes, the possibility has rarely been investigated in human experimental psychopharmacological research.

METHOD

The individual and interactive effects of cannabis and tobacco were evaluated in 24 non-dependent cannabis and tobacco smokers in a randomized, placebo-controlled, double-blind, 2 (cannabis, placebo) × 2 (tobacco, placebo) crossover design. Verbal memory (prose recall), working memory (WM) performance including maintenance, manipulation and attention (N-back), psychotomimetic, subjective and cardiovascular measures were recorded on each of four sessions.

RESULTS

Cannabis alone impaired verbal memory. A priori contrasts indicated that tobacco offset the effects of cannabis on delayed recall. However, this was not supported by linear mixed model analysis. Cannabis load-dependently impaired WM. By contrast, tobacco improved WM across all load levels. The acute psychotomimetic effects and ratings of 'stoned' and 'dizzy' induced by cannabis were not altered by tobacco. Cannabis and tobacco had independent effects on increasing heart rate and interacting effects on increasing diastolic blood pressure.

CONCLUSIONS

Relative to placebo, acute cannabis impaired verbal memory and WM. Tobacco enhanced performance on WM, independently of cannabis. Moreover, we found some preliminary evidence that tobacco may offset the effects of cannabis on delayed, but not immediate, verbal recall. In contrast, the psychotomimetic and subjective effects of cannabis were unaffected by tobacco co-administration. By reducing the cognitive impairment from cannabis, tobacco co-administration may perpetuate use despite adverse health consequences.

Anatomy of a Joint: Comparing Self-Reported and Actual Dose of Cannabis and Tobacco in a Joint, and How These Are Influenced by Controlled Acute Administration

Introduction: Major gaps exist in the measurement of cannabis exposure. The accuracy of self-reported cannabis and tobacco dose per joint is poorly characterized and has never been investigated following acute cannabis/tobacco exposure. Using an innovative "Roll a Joint" paradigm, this study aims to (1) compare estimated and actual dose of cannabis and tobacco per joint at baseline and (2) examine the acute effects of cannabis and/or tobacco on estimated and actual dose. Materials and Methods: We investigated this by using a randomized, double-blind, placebo-controlled crossover 2 (active cannabis, placebo cannabis)×2 (active tobacco, placebo tobacco) design in a laboratory setting. Participants were 24 recreational cousers of cannabis and tobacco. At baseline, they were asked to measure out the amount of cannabis and tobacco they would put in an average joint for themselves (dose per joint). Then, on each of four drug administration sessions, participants were again asked to do this for a joint they would want to smoke "right now." Self-reported and actual amount was recorded (g). Results: At baseline, the estimated amount of cannabis per joint (0.28±0.23 g) was double the actual amount (0.14±0.12 g) (p=0.003, d=0.723). No difference emerged between estimated (0.43±0.25 g) and actual (0.35±0.15 g) (p=0.125) amount of tobacco per joint. Compared to placebo, active cannabis reduced the actual dose of both cannabis (p=0.035) and tobacco (p<0.001) they put in a joint. Participants accurately estimated this reduction for tobacco (p=0.014), but not for cannabis (p=0.680). Conclusions: Self-reported dose per joint is accurate for tobacco but dramatically overestimates cannabis exposure and therefore should be viewed with caution. Cannabis administration reduced the amount of cannabis and tobacco added to joints, suggesting a reduction in dose during a smoking session. The "Roll A Joint" paradigm should be implemented for better accuracy in assessing dose per joint.

The social context moderates the relationship between neighborhood safety and adolescents' activities

Studies of neighborhood safety and physical activity have typically neglected to consider the youth's peer context as a modifier of these relationships. This study fills this gap in testing the independent and interactive effects of perceived neighborhood safety and time spent with friends and peers on young adolescents' physical activity and sedentary behavior. Participants (N = 80; ages 13-17) completed the Pedestrian/Traffic Safety and Crime Safety subscales of the adolescent version of the Neighborhood Environment Walkability Scale (NEWS). An experience sampling methodology was used to assess sedentary behaviors/screen time and the social context in which physical activity and sedentary time/behavior occurred. Physical activity was assessed via accelerometry. Multilevel models were used to estimate the relationships between predictors (neighborhood safety and social context) and outcomes (physical activity and sedentary time/behavior). Frequency of peer/friend interactions moderated the relationships between neighborhood safety and adolescents' physical activity and sedentary behavior. Specifically, physical activity was more strongly influenced by neighborhood safety among adolescents who reported spending less time with peers and friends than among those who reported frequent peer interactions. Among youths who perceived that their neighborhoods were safer, spending more time with friends and peers was related to greater engagement in sedentary activities, whereas this was not the case among adolescents who perceived that their neighborhoods were less safe. The peer social context moderates the relationship between perceived neighborhood safety and adolescents' physical activity and sedentary behavior. Improving social interactions at the individual level within neighborhoods may decrease concerns of safety.

Individual and combined effects of cannabis and tobacco on drug reward processing in non-dependent users

RATIONALE

Cannabis and tobacco are often smoked simultaneously in joints, and this practice may increase the risks of developing tobacco and/or cannabis use disorders. Currently, there is no human experimental research on how these drugs interact on addiction-related measures.

OBJECTIVES

This study aimed to investigate how cannabis and tobacco, each alone and combined together in joints, affected individuals' demand for cannabis puffs and cigarettes, explicit liking of drug and non-drug-related stimuli and craving.

METHOD

A double-blind, 2 (active cannabis, placebo cannabis) × 2 (active tobacco, placebo tobacco) crossover design was used with 24 non-dependent cannabis and tobacco smokers. They completed a pleasantness rating task (PRT), a marijuana purchase task (MPT) and a cigarette purchase task (CPT) alongside measures of craving pre- and post-drug administration.

RESULTS

Relative to placebo cannabis, active cannabis reduced liking of cannabis-associated stimuli and increased response time to all stimuli except cigarette-related stimuli. Relative to placebo cannabis, active cannabis decreased demand for cannabis puffs (trends for breakpoint and elasticity) and cigarettes (breakpoint, P _max, O _max) on several characteristics of the purchase tasks. We found no evidence that active tobacco, both alone or combined with cannabis, had an effect on liking, demand or craving.

CONCLUSIONS

Acutely, cannabis reduced liking of cannabis-related stimuli and demand for cannabis itself. Acute cannabis also reduced demand for cigarettes on the CPT. Acute tobacco administration did not affect demand or pleasantness ratings for cigarettes themselves or cannabis. In non-dependent cannabis and tobacco co-users, tobacco did not influence the rewarding effects of cannabis.

Are adolescents more vulnerable to the harmful effects of cannabis than adults? A placebo-controlled study in human males

Preclinical research demonstrates that cannabinoids have differing effects in adolescent and adult animals. Whether these findings translate to humans has not yet been investigated. Here we believe we conducted the first study to compare the acute effects of cannabis in human adolescent (n=20; 16-17 years old) and adult (n=20; 24-28 years old) male cannabis users, in a placebo-controlled, double-blind cross-over design. After inhaling vaporized active or placebo cannabis, participants completed tasks assessing spatial working memory, episodic memory and response inhibition, alongside measures of blood pressure and heart rate, psychotomimetic symptoms and subjective drug effects (for example, 'stoned', 'want to have cannabis'). Results showed that on active cannabis, adolescents felt less stoned and reported fewer psychotomimetic symptoms than adults. Further, adults but not adolescents were more anxious and less alert during the active cannabis session (both pre- and post-drug administration). Following cannabis, cognitive impairment (reaction time on spatial working memory and prose recall following a delay) was greater in adults than adolescents. By contrast, cannabis impaired response inhibition accuracy in adolescents but not in adults. Moreover, following drug administration, the adolescents did not show satiety; instead they wanted more cannabis regardless of whether they had taken active or placebo cannabis, while the opposite was seen for adults. These contrasting profiles of adolescent resilience (blunted subjective, memory, physiological and psychotomimetic effects) and vulnerability (lack of satiety, impaired inhibitory processes) show some degree of translation from preclinical findings, and may contribute to escalated cannabis use by human adolescents.

Friends and social contexts as unshared environments: a discordant sibling analysis of obesity- and health-related behaviors in young adolescents

OBJECTIVE

This study examines the contribution of best friends' weight and the peer social context (time spent alone versus with friends) as sources of unshared environment associated with variability in weight and health behaviors among weight-discordant siblings.

METHODS

Pairs of same-sex biologic siblings (N=40 pairs; ages 13-17) were originally recruited as part of a study evaluating putative factors contributing to differences in adiposity among weight-discordant siblings. Siblings were asked to bring their best friends to the laboratory and siblings and friends' height and weight were objectively measured. Siblings also completed multi-pass dietary recalls to assess energy intake and sugar sweetened beverage (SSB) consumption. Siblings' physical activity was measured using accelerometry. Experience sampling methodology was used to assess sedentary behaviors/screen time and the number of occasions siblings spent alone and in the presence of friends. Multilevel models were used to estimate the relationships between predictors (best friends' zBMI, time spent alone or with friends) and outcomes (siblings' zBMI and obesity-related health behaviors).

RESULTS

Best friends' zBMI was the best predictor of participants' zBMI, even when controlling for child's birth weight. Best friends' weight (zBMI) further predicted participants' SSB intake and time engaged in sedentary behaviors. Being active with friends was positively associated with participants' overall physical activity, whereas spending time alone was negatively associated with accelerometer counts regardless of siblings' adiposity.

CONCLUSIONS

A friends' weight and the social context are unshared environmental factors associated with variability in adiposity among biologically-related weight-discordant siblings.

No Smoke without Tobacco: A Global Overview of Cannabis and Tobacco Routes of Administration and Their Association with Intention to Quit

Cannabis and tobacco are common drugs of abuse worldwide and are often used in combination through various routes of administration (ROAs). Here, we aimed to provide an overview of how cannabis and tobacco routes varied across countries and assess the impact of tobacco-based ROAs on motivation to use less cannabis, and less tobacco, in different models. A cross-sectional online survey (Global Drugs Survey 2014) was completed by 33,687 respondents (mean age = 27.9; % female = 25.9) who smoked cannabis at least once in the last 12 months. Most common ROA, frequency of cannabis/tobacco use, and questions about motivation to use less cannabis/tobacco were recorded. Tobacco-based ROA were used by 65.6% of respondents. These were most common in Europe (77.2-90.9%) and Australasia (20.7-51.6%) and uncommon in the Americas (4.4-16.0%). Vaporizer use was most common in Canada (13.2%) and the United States (11.2%). Using a non-tobacco ROA was associated with a 10.7% increase in odds for "desire to use less" tobacco (OR: 1.107, 95% CI: 1.003, 1.221), 80.6% increase in odds for "like help to use less tobacco" (OR: 1.806, 95% CI: 1.556, 2.095), and a 103.9% increase in the odds for "planning to seek help to use less tobacco" (OR: 2.039, 95% CI: 1.638, 2.539), in comparison to using a tobacco-based ROA. Associations between ROA and intentions to use less cannabis were inconsistent. Results support considerable global variation in cannabis and tobacco ROA. Tobacco routes are common, especially "joints with tobacco," especially in Europe, but not in the Americas. Non-tobacco-based routes are associated with increased motivation to change tobacco use. Interventions addressing tobacco and cannabis need to accommodate this finding and encourage non-tobacco routes.