Sex Differences in Neuropsychological Functioning are Domain-Specific in Adolescent and Young Adult Regular Cannabis Users

Investigating sex differences and age of onset in emotion regulation, executive functioning, and cannabis use in adolescents and young adults

BACKGROUND

Young adults have historically high levels of cannabis use at a time which coincides with emotional and cognitive development. Age of regular onset of cannabis use and sex at birth are hypothesized to influence the relationship between cannabis use and cognition. Here we investigated past 6-month cannabis use in relation to emotional and executive functioning. We further considered age of onset and sex in subgroup analyses.

METHOD

Young adults (N = 225; ages 16-22) completed a substance use interview and cognitive battery, including the Emotional Word-Emotional Face Stroop and NIH toolbox executive functioning tasks. Linear regressions examined relationships between past 6-month cannabis use episodes and performance. Subgroup analyses investigated whether age of onset or sex impacted relationships.

RESULTS

After correcting for multiple comparisons, greater past 6-month cannabis use episodes were related to poorer Emotional Stroop Congruent Accuracy (p = .0004, FDR-p = .002) and List Sorting Working Memory (p = .02, FDR-p = .10) performance. Younger age of regular use onset marginally related to lower Emotional Stroop Congruent Accuracy performance (p = .03, FDR-p = .13). There were no cannabis use by sex interactions on cognition.

CONCLUSIONS

Consistent with prior findings, results suggest small reductions in cannabis-related performance in processing speed during emotional Stroop and working memory tasks. Age of onset was modestly related to Stroop performance, but not sex. Longitudinal studies which detail patterns of cannabis and other substance use are needed to better assess brain-behavior relationships and other factors (e.g., age of onset of regular use, sex) which could influence cannabis-related impairments in cognitive functioning.

Measuring cannabis quantities in online surveys: A rapid review and proposals for ways forward

OBJECTIVES

Cannabis use quantities are relevant for determining cannabis-related harms. This research aims to provide an overview of the available methods to assess quantities through self-report.

METHODS

A rapid review of various strategies to collect information on cannabis use quantities through self-report. Two independent literature searches resulted in n = 38 studies included for review.

RESULTS

A total of n = 14 studies employed methods for collecting cannabis use quantities that are not suitable for online surveys (e.g., rolling a fake joint). Of the remaining n = 24 studies with items that are suitable for online surveys, the quantity assessment was performed in three different ways. The data collection was either carried out by asking (a) for the total number of joints (i.e., crude joint method), (b) for the total weight (i.e., crude weight method), or (c) for specific products separately, for example, for the amount of flower and resin (i.e., product-specific method). In only n = 8 studies, cannabis use quantities were ascertained by providing visual aids (e.g., illustration of various amounts of flower).

CONCLUSIONS

The crude joint method and the product-specific method are the two most promising methods to collect information on cannabis use quantities. Using visual aids may potentially improve the accuracy of those methods.

A Meta-Analysis of fMRI Studies of Youth Cannabis Use: Alterations in Executive Control, Social Cognition/Emotion Processing, and Reward Processing in Cannabis Using Youth

Background: Adolescent cannabis use (CU) is associated with adverse health outcomes and may be increasing in response to changing cannabis laws. Recent imaging studies have identified differences in brain activity between adult CU and controls that are more prominent in early onset users. Whether these differences are present in adolescent CU and relate to age/developmental stage, sex, or cannabis exposure is unknown. Methods: A systematic review and subsequent effect-size seed-based d mapping (SDM) meta-analysis were conducted to examine differences in blood-oxygen-level-dependent (BOLD) response during fMRI studies between CU and non-using typically developing (TD) youth. Supplemental analyses investigated differences in BOLD signal in CU and TD youth as a function of sex, psychiatric comorbidity, and the dose and severity of cannabis exposure. Results: From 1371 citations, 45 fMRI studies were identified for inclusion in the SDM meta-analysis. These studies compared BOLD response contrasts in 1216 CU and 1486 non-using TD participants. In primary meta-analyses stratified by cognitive paradigms, CU (compared to TD) youth showed greater activation in the rostral medial prefrontal cortex (rmPFC) and decreased activation in the dorsal mPFC (dmPFC) and dorsal anterior cingulate cortex (dACC) during executive control and social cognition/emotion processing, respectively. In meta-regression analyses and subgroup meta-analyses, sex, cannabis use disorder (CUD) severity, and psychiatric comorbidity were correlated with brain activation differences between CU and TD youth in mPFC and insular cortical regions. Activation differences in the caudate, thalamus, insula, dmPFC/dACC, and precentral and postcentral gyri varied as a function of the length of abstinence. Conclusions: Using an SDM meta-analytic approach, this report identified differences in neuronal response between CU and TD youth during executive control, emotion processing, and reward processing in cortical and subcortical brain regions that varied as a function of sex, CUD severity, psychiatric comorbidity, and length of abstinence. Whether aberrant brain function in CU youth is attributable to common predispositional factors, cannabis-induced neuroadaptive changes, or both warrants further investigation.

The role of sex in the association between cannabis use and working memory-related brain activity

Although cannabis use patterns differ between men and women, studies on sex differences on the effects of cannabis on the brain and cognitive control are largely lacking. Working memory (WM) is a component of cognitive control believed to be involved in the development and maintenance of addiction. In this study, we evaluated the association between cannabis use and WM (load) related brain activity in a large sample, enabling us to assess sex effects in this association. The brain activity of 104 frequent cannabis users (63% men) and 85 controls (53% men) was recorded during an N‐back WM task. Behavioral results showed a significant interaction between WM load and group for both accuracy and reaction time, with cannabis users showing a relatively larger decrease in performance with increasing WM load. Cannabis users compared to controls showed a relatively smaller reduction in WM (load) related activity in the precuneus and posterior cingulate cortex at higher WM load. This WM (load) related activity was not associated with performance nor cannabis use and related problems. An exploratory analysis showed higher WM‐related activity in the superior frontal gyrus in men compared to women. While cannabis users showed higher WM (load) related activity in central nodes of the default mode network, this was not directly attributable to group specific worsening of performance under higher cognitive load. Further research is necessary to assess whether observed group differences increase with higher cognitive load, how group differences relate to measures of cannabis use, and how sex affects these group differences.

Clouding up cognition?: Secondhand cannabis and tobacco exposure related to cognitive functioning in youth

Background

Increasing legalization of cannabis, in addition to longstanding rates of tobacco use, raises concerns for possible cognitive decrements from secondhand smoke or environmental exposure, although little research exists. We investigate the relation between cognition and secondhand and environmental cannabis and tobacco exposure in youth.

Methods

The Adolescent Brain Cognitive Development (ABCD) Study year 2 follow-up (N = 5580; 48% female) cognitive performance and secondhand or environmental cannabis or tobacco exposure data were used. Principal components analysis identified a global cognition factor. Linear mixed-effects models assessed global cognition and individual cognitive task performance by cannabis and/or tobacco environmental exposure. Sociodemographics and other potential confounds were examined. p values were adjusted using the false discovery rate method.

Results

Global cognition was not related to any exposure group after testing corrections and considering confounds. Beyond covariates and family- and site-level factors, secondhand tobacco was related to poorer visual memory (p = .02), and environmental tobacco was associated with poorer visuospatial (p = .02) and language (p = .008) skills. Secondhand cannabis was related to cognition, but not after controlling for potential confounders (p > .05). Environmental cannabis was related to better oral reading (p = .01). Including covariates attenuated effect sizes.

Conclusions

Secondhand tobacco exposure was associated with poorer visual memory, while environmental tobacco exposure was related to poorer language and visuospatial skills. Secondhand cannabis was not related to cognition after controlling for sociodemographic factors, but environmental cannabis exposure was related to better reading. Because, to our knowledge, this is the first known study of its kind and thus preliminary, secondhand cannabis should continue to be investigated to confirm results.