Emotion regulation deficits in regular marijuana users

The Effects of Cannabidiol and δ-9-Tetrahydrocannabinol in Social Cognition: A Naturalistic Controlled Study

Background: Social cognition abilities such as empathy and the Theory of Mind (ToM) have been shown to be impaired in neuropsychiatric conditions such as psychotic, autistic, and bipolar disorders. The endocannabinoid system (ECS) seems to play a role in social behavior and emotional processing while it also seems to play a role in those neuropsychiatric conditions showing social cognition impairments. Main plant cannabinoids delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) modulate the ECS and, due to their opposite effects, have been proposed as both cause and treatment for neuropsychiatric-related disorders such as schizophrenia, anxiety, or post-traumatic stress disorder (PTSD). The aim of this study was to test the effects of THC and CBD on social cognition abilities in chronic cannabis users. Method: Eighteen members from a cannabis social club were tested for social cognition effects under the effects of different full spectrum cannabis extracts containing either THC, CBD, THC+CBD, or placebo in a naturalistic randomized double-blind crossover placebo-controlled study. Results: Results showed that participants under the effects of THC showed lower cognitive empathy when compared with the effects of CBD but not when those were compared with THC+CBD or placebo. Also, participants showed higher cognitive ToM under the effects of CBD when compared with the effects of placebo, but not when those were compared with THC or THC+CBD. However, we did not find differences on the emotional scales for empathy or ToM. Conclusions: This study provides evidence for the interaction between the effects of THC and CBD and social cognition abilities in a naturalistic environment, which can be of special interest for the clinical practice of medical cannabis on neuropsychiatric disorders. We show for the first time that CBD can improve ToM abilities in chronic cannabis users. Our results might help to understand the role of the ECS in social cognition, and their association with psychiatric and neurodevelopmental disorders such as schizophrenia or autism. Finally, we demonstrate how reliable methodologies can be implemented in naturalistic environments to collect valid ecological evidence outside classic laboratory settings.

Examining the relationship between non-suicidal self-injury and mental health among female Arab minority students: the role of identity conflict and acculturation stress

Background and objective

Research suggests that individuals from minority backgrounds, including immigrants and ethnic minorities, may be at a higher risk for non-suicidal self-injury (NSSI). The aim of the present research is to examine the relationship between non-suicidal self-injury (NSSI) and identity conflict and acculturation stress, depression, and risk behaviors among female Arab minority students.

Methods

The sample analyzed consisted of 1,529 female Arab students (85.8% B.A. students, 14% M.A. students) aged 21-54 (M = 23, SD = 4.17). The participants completed self-reported questionnaires assessing NSSI engagement, identity conflict and acculturation stress, depression, and risky substance use behavior.

Results

As expected, we found a significant positive association between NSSI and identity crisis. In addition, an identity conflict and acculturation stress impact the effect of depression and risky substance use behaviors in engaging in self-injury. Namely, participants were more likely to engage in NSSI when they also experienced identity conflict and acculturation stress and exhibited depressive symptoms and tended to display risky substance use behavior.

Conclusion

These findings provide evidence that the relationship between depression, risky substance use behavior, and NSSI may be stronger among individuals who experience higher levels of identity conflict and acculturation stress. Implications for intervention and future research are briefly presented.

Sex Moderates Associations Between Dimensions of Emotion Dysregulation and Problematic Cannabis Use

The current study examined whether sex moderates associations between emotion dysregulation (overall and six dimensions of emotion dysregulation) and problematic cannabis use. 741 adult past-month cannabis users (31.44% female) completed questionnaires on problematic cannabis use (Marijuana Problems Scale) and emotion dysregulation (Difficulties in Emotion Regulation Scale). Mann-Whitney U tests and hierarchical multiple linear regressions were performed. Male cannabis users reported greater difficulties with overall emotion dysregulation, nonacceptance, goals, impulse, strategies, and clarity. Overall emotion dysregulation, nonacceptance, goals, impulse, and strategies were associated with more severe problematic cannabis use, with relationships weaker in female cannabis users. Lack of emotional awareness was associated with less severe problematic cannabis use in male cannabis users only. Examining individual differences in emotion dysregulation as they relate to problematic cannabis use suggests that treatments may need to be tailored for male cannabis users with a focus on specific emotion dysregulation dimensions.

Opposing and emotion-specific associations between frontal activation with depression and anxiety symptoms during facial emotion processing in generalized anxiety and depression

Major depression (MDD) and generalized anxiety disorder (GAD) have become one of the leading global causes of disability and both are characterized by marked interpersonal and social impairments. However, despite high comorbidity and overlapping social-emotional deficits, it remains unclear whether MDD and GAD share a common neural basis during interpersonal processing. In the present study, we combined an emotional face processing paradigm with fMRI and dimensional and categorical analyses in a sample of unmedicated MDD and GAD patients (N = 72) as well as healthy controls (N = 35). No group differences were found in categorical analyses. However, the dimensional analyses revealed that dorsolateral prefrontal cortex (dlPFC) reactivity to sad facial expressions was positively associated with depression symptom load, yet negatively associated with anxiety symptom load in the entire sample. On the network level depression symptom load was positively associated with functional connectivity between the bilateral amygdala and a widespread network including the anterior cingulate and insular cortex. Together, these findings suggest that the dlPFC - engaged in cognitive and emotional processing - exhibits symptom- and emotion-specific alteration during interpersonal processing. Dysregulated communication between the amygdala and core regions of the salience network may represent depression-specific neural dysregulations.

Individually delivered mindfulness-based cognitive therapy in concomitant problematic substance use and emotional symptoms: A process-based case study

The process-based approach assumes that transdiagnostic psychological processes are involved in the onset and maintenance of mental disorders. Case conceptualization is used to identify such psychological processes and to individualize the intervention accordingly. This approach is fundamentally different from syndrome-based approaches in which standardized treatments are administered for psychiatric diagnoses or symptoms. In the current case, we proposed a process-based conceptualization and treatment for a woman with concomitant problematic substance use and emotional symptoms. Our idiosyncratic process-based conceptualization showed that for this person, substance abuse consisted in a maladaptive coping strategy to deal with repetitive negative thinking and poor emotion regulation skills, for which we decided to use a mindfulness-based intervention. Treatment comprised 8 weeks of individually delivered mindfulness-based cognitive therapy sessions. A comprehensive assessment of psychiatric symptoms and psychological processes was conducted at baseline, post-intervention and 3-month follow-up. The post-treatment assessment revealed that psychological processes targeted by the intervention were improved, together with the mindfulness trait. At the symptom-based level, we observed a significant reduction in substance abuse and emotional symptoms. Treatment gains were maintained at follow-up. From a process-based perspective, this result implies that the intervention successfully targeted the psychological processes underlying the presenting symptoms. Adopting a process-based approach rather than symptom- or syndrome-based approaches is a valuable alternative in the conceptualization and treatment of complex cases presenting with multiple comorbidities.

Trauma exposure among cannabis use disorder individuals was associated with a craving-correlated non-habituating amygdala response to aversive cues

The relationship of cannabis-use disorder and trauma exposure at the level of the brain is not well-understood. Cue-reactivity paradigms have largely focused on characterizing aberrant subcortical function by averaging across the entire task. However, changes across the task, including a non-habituating amygdala response (NHAR), may be a useful biomarker for relapse vulnerability and other pathology. This secondary analysis utilized existing fMRI data from a CUD population with (TR-Y, n = 18) or without trauma (TR-N, n = 15). Amygdala reactivity to novel and repeated aversive cues was examined between TR-Y vs. TR-N groups, using a repeated measures ANOVA. Analysis revealed a significant interaction between TR-Y vs. TR-N and amygdala response to novel vs. repeated cues in the amygdala (right: F (1,31) = 5.31, p = 0.028; left: F (1,31) = 7.42, p = 0.011). In the TR-Y group, a NHAR was evident, while the TR-N group exhibited amygdala habituation, resulting in a significant difference between groups of amygdala reactivity to repeated cues (right: p = 0.002; left: p < 0.001). The NHAR in the TR-Y (but not TR-N) group was significantly correlated with higher cannabis craving scores, yielding a significant group difference (z = 2.1, p = 0.018). Results suggest trauma interacts with the brain's sensitivity to aversive cues, offering a neural explanation for the relationship between trauma and CUD vulnerability. These findings suggest the importance of considering the temporal dynamics of cue reactivity and trauma history in future studies and treatment planning, as this distinction may help decrease relapse vulnerability.

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 Pattern of Substance Use among People Who Use Drugs (PWUD) Receiving Treatment at University Malaya Medical Centre (UMMC) during the COVID-19 Pandemic and the Associated Factors

There was a change in the pattern of substance usage among people who use substances during the COVID-19 pandemic period. This study aims to determine the effects of the COVID-19 pandemic on the pattern of substance usage among people who use drugs (PWUD) receiving treatment at the University Malaya Medical Centre (UMMC) as well as levels of anxiety and depression together with coping mechanisms and the factors affecting the pattern of substance use during COVID-19 pandemic period. A cross-sectional study was applied. The questionnaire used was the Mini-European Web Survey on Drugs (EWSD): COVID-19, Hospital Anxiety and Depression Scale (HADS), and Brief COPE Scale. In total, 130 PWUD were recruited. Of the participants, 36.2% of PWUD had not used/stopped the usage of illicit drugs/alcohol, 26.2% increased their usage, 20% decreased, and 14.6% used the same amount of illicit substances/alcohol during the COVID-19 pandemic period/restrictions. In addition, 28.5% of PWUD had an increased intention to seek professional support for drug counseling/treatment during the COVID-19 pandemic period. The prevalence anxiety and depression symptoms in PWUD according to HADS was 33% and 41.5%, respectively, with depression (p = 0.05) and isolation status (adjusted OR = 2.63, p < 0.05) being associated with an increase in alcohol/illicit substance use during the COVID-19 pandemic. PWUD who had increased their intention to seek professional support had significantly higher odds (adjusted OR = 4.42, p < 0.01) of reducing their alcohol/illicit substance use during the COVID-19 pandemic period. There were increased odds of maintaining alcohol/illicit substance usage among PWUD who practiced dysfunctional coping (adjusted OR = 3.87, p < 0.025) during the COVID-19 pandemic period. In conclusion, depression, isolation status, dysfunctional coping, and intention to seek professional support affected the pattern of alcohol/illicit substance use during the COVID-19 pandemic period. Strategies, substance rehabilitation/counseling, and proper mental health screening and the associated risk factors must be emphasized to prevent a further epidemic of substance use during the pandemic.

Effort-based decision making and self-reported apathy in frequent cannabis users and healthy controls: A replication and extension

INTRODUCTION

Amotivational syndrome is a term used to refer to lack of motivation and passive personality related to chronic cannabis use. Given mixed findings, the current study aimed to replicate and extend previous research on frequent cannabis use, motivated behavior, and self-reported apathy.

METHOD

Cannabis users (on average, ≥3 days/week of cannabis use over the past year), and healthy controls (≤1 day/month of cannabis use over the past year) completed the Apathy Evaluation Scale (AES), and the Effort Expenditure for Rewards Task (EEfRT). Repeated measures analysis of covariance was used to 1) examine the effects of group, reward magnitude, probability, and their interaction on hard task selections on the EEfRT, and 2) examine between-group differences on the AES, controlling for alcohol use and depressive symptoms.

RESULTS

There were significant main effects of reward magnitude, probability, and an interaction between reward magnitude and probability on hard task selection (p's < 0.05). Specifically, as reward magnitude and probability of winning the reward increased, participants were more likely to select hard tasks on the EEfRT. Relative to healthy controls, cannabis users were significantly more likely to select hard tasks on the EEfRT (F(1,56) = 6.49, p = 0.014, η_p² = 0.10). When controlling for alcohol use and depressive symptoms, no significant group differences in self-reported apathy were present (p = 0.46).

CONCLUSIONS

Cannabis users exhibit a greater likelihood of exerting more effort for reward, suggesting enhanced motivation relative to healthy controls. Thus, the current results do not support amotivational syndrome in adult frequent cannabis users. Despite some harms of long-term cannabis use, amotivation may not be among them.

Cannabis consumption and prosociality

The existing literature largely focuses on health risks and other pharmacodynamics of using cannabis, with fewer investigations of other normative psychological effects from consumption among otherwise healthy people. We measured several basic constructs of social psychology corresponding to the concept of prosociality among 146 healthy young adults between 18 and 25 years (M = 18.9, SD = 1.4) with varying detectable levels of tetrahydrocannabinol (THC) in their urine, controlling for participant’s sex, age, ethnicity, and childhood socio-economic status. Compared to THC-free individuals, cannabis users scored higher than non-users on validated measures of Prosocial Behaviors (d = .34, p = .04), the Empathy Quotient (d = .36, p < .01), Moral Harmlessness (d = .76, p < .01) and Moral Fairness (d = .49, p < .01), but exhibited a lower sense of Ingroup Loyalty (d = .33, p = .04). Relative to THC-free, same-sex individuals, female cannabis users scored significantly higher on measurements of Aggression (ds = .65 and .57, ps < .05) and male users scored higher on the Agreeableness dimension of personality (d = .91, p < .01).. Linear associations were found between the recency of last cannabis usage and the Prosocial Behaviors, Empathy Quotient, Moral Harmlessness, Moral Fairness and Agreeableness personality scores (rs from − .24 to .38, ps < .05). The findings suggest cannabis usage is associated with an increased sense of prosociality and prioritization of humanitarian behaviors that declines with time following cannabis consumption. Further research should focus on heterogeneity in the effects of cannabis consumption across users.

Cigarette smoking is associated with difficulties in the use of reappraisal for emotion regulation

BACKGROUND

Negative emotions can promote smoking relapse during a quit attempt. The use of cognitive reappraisal to self-regulate these emotions may therefore aid smoking cessation. Determining whether smokers exhibit difficulties in the use of reappraisal, and which factors are associated with such difficulties, may aid smoking cessations.

METHODS

50 smokers and 50 non-smokers completed an online reappraisal task in which they either reappraised or naturally experienced emotions induced by negatively- and neutrally-valenced images that presented situations in either the 1st-person or 3rd-person perspective. Participants also completed the Difficulties in Emotion Regulation Scale (DERS).

RESULTS

Compared to non-smokers, smokers were less successful in using reappraisal to self-regulate emotions elicited by negatively-valenced images (but not neutrally-valenced images). Importantly, this effect was only true for images that were presented in the 1st-person (but not 3rd-person) perspective. Contrary to predictions, there were no group differences in DERS scores.

CONCLUSIONS

This study provides the first evidence that smokers experience difficulties in the use of reappraisal, particularly in situations that appear to be happening to themselves. Because the use of this regulation technique may help smokers to quit, improving smokers' abilities to use reappraisal, particularly during negatively-valenced situations that directly influence the smoker, may aid smoking cessation.

Systematic review of structural and functional neuroimaging studies of cannabis use in adolescence and emerging adulthood: evidence from 90 studies and 9441 participants

Cannabis use peaks in adolescence, and adolescents may be more vulnerable to the neural effects of cannabis and cannabis-related harms due to ongoing brain development during this period. In light of ongoing cannabis policy changes, increased availability, reduced perceptions of harm, heightened interest in medicinal applications of cannabis, and drastic increases in cannabis potency, it is essential to establish an understanding of cannabis effects on the developing adolescent brain. This systematic review aims to: (1) synthesize extant literature on functional and structural neural alterations associated with cannabis use during adolescence and emerging adulthood; (2) identify gaps in the literature that critically impede our ability to accurately assess the effect of cannabis on adolescent brain function and development; and (3) provide recommendations for future research to bridge these gaps and elucidate the mechanisms underlying cannabis-related harms in adolescence and emerging adulthood, with the long-term goal of facilitating the development of improved prevention, early intervention, and treatment approaches targeting adolescent cannabis users (CU). Based on a systematic search of Medline and PsycInfo and other non-systematic sources, we identified 90 studies including 9441 adolescents and emerging adults (n = 3924 CU, n = 5517 non-CU), which provide preliminary evidence for functional and structural alterations in frontoparietal, frontolimbic, frontostriatal, and cerebellar regions among adolescent cannabis users. Larger, more rigorous studies are essential to reconcile divergent results, assess potential moderators of cannabis effects on the developing brain, disentangle risk factors for use from consequences of exposure, and elucidate the extent to which cannabis effects are reversible with abstinence. Guidelines for conducting this work are provided.

Examining Inhibitory Affective Processing Within the Rostral Anterior Cingulate Cortex Among Abstinent Cannabis-Using Adolescents and Young Adults

Cannabis use has been associated with deficits in self-regulation, including inhibitory control. Cannabis users have previously exhibited both structural and functional deficits in the rostral anterior cingulate cortex (rACC), a region involved in self-regulation of emotional response and inhibitory control. The present study aimed to examine whether abstinent cannabis users demonstrated abnormal functional activation and connectivity of the bilateral rACC during an emotional inhibitory processing task, and whether gender moderated these relationships. Cannabis-using (N = 34) and non-using (N = 32) participants ages 16-25 underwent at least 2-weeks of monitored substance use abstinence (excluding tobacco) and fMRI scanning while completing a Go/No-go task using fearful and calm emotional faces as non-targets. Multiple linear regression and ANCOVA were used to determine if cannabis group status was related to rACC activation and context-dependent functional connectivity, and whether gender moderated these relationships. Results showed decreased bilateral rACC activation in cannabis users during fearful response inhibition, although groups did not show any context-dependent connectivity differences between the left or right rACC during calm or fearful inhibition. Gender findings revealed that cannabis-using females compared to males did show aberrant connectivity between the right rACC and right cerebellum. These results are consistent with literature demonstrating aberrant structural and functional rACC findings and suggest that chronic cannabis use may disrupt typical rACC development-even after abstinence-potentially conferring risk for later development of mood disorders. Marginal gender-specific connectivity findings bolster continued findings regarding female vulnerability to effects of cannabis on cognition and affect. Findings should be assessed in longitudinal studies to determine causality and timing effects.

Serotonin and early life stress interact to shape brain architecture and anxious avoidant behavior - a TPH2 imaging genetics approach

BACKGROUND

Early life stress has been associated with emotional dysregulations and altered architecture of limbic-prefrontal brain systems engaged in emotional processing. Serotonin regulates both, developmental and experience-dependent neuroplasticity in these circuits. Central serotonergic biosynthesis rates are regulated by Tryptophan hydroxylase 2 (TPH2) and transgenic animal models suggest that TPH2-gene associated differences in serotonergic signaling mediate the impact of aversive early life experiences on a phenotype characterized by anxious avoidance.

METHODS

The present study employed an imaging genetics approach that capitalized on individual differences in a TPH2 polymorphism (703G/T; rs4570625) to determine whether differences in serotonergic signaling modulate the effects of early life stress on brain structure and function and punishment sensitivity in humans (n = 252).

RESULTS

Higher maltreatment exposure before the age of 16 was associated with increased gray matter volumes in a circuitry spanning thalamic-limbic-prefrontal regions and decreased intrinsic communication in limbic-prefrontal circuits selectively in TT carriers. In an independent replication sample, associations between higher early life stress and increased frontal volumes in TT carriers were confirmed. On the phenotype level, the genotype moderated the association between higher early life stress exposure and higher punishment sensitivity. In TT carriers, the association between higher early life stress exposure and punishment sensitivity was critically mediated by increased thalamic-limbic-prefrontal volumes.

CONCLUSIONS

The present findings suggest that early life stress shapes the neural organization of the limbic-prefrontal circuits in interaction with individual variations in the TPH2 gene to promote a phenotype characterized by facilitated threat avoidance, thus promoting early adaptation to an adverse environment.

Reduced Segregation Between Cognitive and Emotional Processes in Cannabis Dependence

Addiction is characterized by an erosion of cognitive control toward drug taking that is accentuated by negative emotional states. Here we tested the hypothesis that enhanced interference on cognitive control reflects a loss of segregation between cognition and emotion in addiction. We analyzed Human Connectome Project data from 1206 young adults, including 89 with cannabis dependence (CD). Two composite factors, one for cognition and one for emotion, were derived using principal component (PC) analyses. Component scores for these PCs were significantly associated in the CD group, such that negative emotionality correlated with poor cognition. However, the corresponding component scores were uncorrelated in matched controls and nondependent recreational cannabis users (n = 87). In CD, but not controls or recreational users, functional magnetic resonance imaging activations to emotional stimuli (angry/fearful faces > shapes) correlated with activations to cognitive demand (working memory; 2-back > 0-back). Canonical correlation analyses linked individual differences in cognitive and emotional component scores with brain activations. In CD, there was substantial overlap between cognitive and emotional brain-behavior associations, but in controls, associations were more restricted to the cognitive domain. These findings support our hypothesis of impaired segregation between cognitive and emotional processes in CD that might contribute to poor cognitive control under conditions of increased emotional demand.

A unifying translational framework to advance treatment research for comorbid PTSD and substance use disorders

We provide a unifying translational framework that can be used to synthesize extant lines of human laboratory research in four neurofunctional domains that underlie the co-occurrence of posttraumatic stress and substance use disorders (PTSD+SUD). We draw upon the Alcohol and Addiction Research Domain Criteria (AARDOC) to include executive functioning, negative emotionality, reward, and added social cognition from the National Institute of Mental Health (NIMH) Research Domain Criteria into our framework. We review research findings across each of the four domains, emphasizing human experimental studies in PTSD, SUD, and PTSD+SUD for each domain. We also discuss the implications of research findings for treatment development by considering new ways of conceptualizing risk factors and outcomes at the level of the individual patient, which will enhance treatment matching and advance innovations in intervention.

Convergent cross-sectional and longitudinal evidence for gaming-cue specific posterior parietal dysregulations in early stages of internet gaming disorder

Exaggerated reactivity to drug-cues and emotional dysregulations represent key symptoms of early stages of substance use disorders. The diagnostic criteria for (Internet) gaming disorder strongly resemble symptoms for substance-related addictions. However, previous cross-sections studies revealed inconsistent results with respect to neural cue reactivity and emotional dysregulations in these populations. To this end, the present fMRI study applied a combined cross-sectional and longitudinal design in regular online gamers (n = 37) and gaming-naïve controls (n = 67). To separate gaming-associated changes from predisposing factors, gaming-naive subjects were randomly assigned to 6 weeks of daily Internet gaming or a non-gaming condition. At baseline and after the training, subjects underwent an fMRI paradigm presenting gaming-related cues and non-gaming-related emotional stimuli. Cross-sectional comparisons revealed gaming-cue specific enhanced valence attribution and neural reactivity in a parietal network, including the posterior cingulate in regular gamers as compared to gaming naïve-controls. Longitudinal analysis revealed that 6 weeks of gaming elevated valence ratings as well as neural cue-reactivity in a similar parietal network, specifically the posterior cingulate in previously gaming-naïve controls. Together, the longitudinal design did not reveal supporting evidence for altered emotional processing of non-gaming associated stimuli in regular gamers whereas convergent evidence for increased emotional and neural reactivity to gaming-associated stimuli was observed. Findings suggest that exaggerated neural reactivity in posterior parietal regions engaged in default mode and automated information processing already occur during early stages of regular gaming and probably promote continued engagement in gaming behavior.

A Mini-Review of Relationships Between Cannabis Use and Neural Foundations of Reward Processing, Inhibitory Control and Working Memory

Cannabis is commonly used, and use may be increasing in the setting of increasing legalization and social acceptance. The scope of the effects of cannabis products, including varieties with higher or lower levels of Δ9-tetrahydrocannabinol (THC) or cannabidiol (CBD), on domains related to addictive behavior deserves attention, particularly as legalization continues. Cannabis use may impact neural underpinnings of cognitive functions linked to propensities to engage in addictive behaviors. Here we consider these neurocognitive processes within the framework of the dual-process model of addictions. In this mini-review, we describe data on the relationships between two main constituents of cannabis (THC and CBD) and neural correlates of reward processing, inhibitory control and working memory.

The relationship between alcohol and cannabis use with nonsuicidal self-injury among adolescent inpatients: Examining the 90 days prior to psychiatric hospitalization

BACKGROUND

This study examined the trajectories of alcohol use, cannabis use, suicide planning (SP), and nonsuicidal self-injury (NSSI) prior to hospitalization and examined the role of alcohol and cannabis use, independently and jointly, in predicting NSSI on a daily level and over time.

METHODS

Participants included 71 adolescents hospitalized for suicide risk (75% female; 25% male; M_age = 15.79). All participants drank alcohol at least once in the prior 90-days. We conducted mixed effect models to assess the trajectories of alcohol use, cannabis use, and NSSI over the 90-days prior hospitalization. To test the effect of SP, alcohol use, and cannabis use on NSSI, we conducted logistic random effect models, while controlling for demographics.

RESULTS

SP (OR = 4.47, p < 0.001) and suicide ideation (SI) (OR = 10.09, p < 0.001) significantly increased the odds of engaging in NSSI. Neither cannabis nor alcohol use independently predicted the odds of engaging in NSSI, however, the co-occurrence of alcohol and cannabis use increased the odds of engaging in NSSI on a given day (OR = 30.5, p < 0.05).

CONCLUSIONS

Study findings extend current knowledge about the longitudinal and day-to-day relationships between alcohol and cannabis use and NSSI. Results underscore the importance of developing interventions that address polysubstance use among suicidal adolescents engaging in NSSI.

Emotion regulation in emerging adults with major depressive disorder and frequent cannabis use

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Linear mixed modelling was used to analyze fMRI data on an emotion task.

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Cannabis use and major depressive disorder interacted with emotion regulation.

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The biggest effects were observed in the left temporal lobe.

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Emotion regulation strategy and depressive symptoms also predicted activity.

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The combination of MDD and cannabis was more complex than strictly additive.

In people with mental health issues, approximately 20% have co-occurring substance use, often involving cannabis. Although emotion regulation can be affected both by major depressive disorder (MDD) and by cannabis use, the relationship among all three factors is unknown. In this study, we used fMRI to evaluate the effect that cannabis use and MDD have on brain activation during an emotion regulation task. Differences were assessed in 74 emerging adults aged 16–23 with and without MDD who either used or did not use cannabis. Severity of depressive symptoms, emotion regulation style, and age of cannabis use onset were also measured. Both MDD and cannabis use interacted with the emotion regulation task in the left temporal lobe, however the location of the interaction differed for each factor. Specifically, MDD showed an interaction with emotion regulation in the middle temporal gyrus, whereas cannabis use showed an interaction in the superior temporal gyrus. Emotion regulation style predicted activity in the right superior frontal gyrus, however, this did not interact with MDD or cannabis use. Severity of depressive symptoms interacted with the emotion regulation task in the left middle temporal gyrus. The results highlight the influence of cannabis use and MDD on emotion regulation processing, suggesting that both may have a broader impact on the brain than previously thought.

Altered resting functional connectivity patterns associated with problematic substance use and substance use disorders during adolescence

BACKGROUND

Adolescence is typified by increasing rates of substance use and the development of substance use disorders (SUD). Aberrant connectivity between cortical regions involved in executive control, and subcortical regions has been suggested to be associated with SUD and problematic substance use among adolescents. Few studies, however, have investigated system-level or whole-brain functional connectivity (FC) in order to test this hypothesis.

METHODS

In a sample of 114 adolescents (mean age = 17.62 years, SD = 1.23, 61F) from the community, the present study used resting-state functional magnetic resonance imaging and independent component analysis to study executive control-subcortical network (ECN-SCN) coupling in adolescent SUD (n=18) and problematic substance use (n=34). In addition, whole-brain FC analyses were also conducted.

RESULTS

Problematic substance use, but not SUD, was associated with increased negative ECN-SCN coupling (p = 0.026). The whole-brain FC analysis showed insula-associated hypoconnectivity in the SUD group (p = 0.037), which was negatively correlated with frequency of substance use.

CONCLUSIONS

Findings implicate different neural circuitry underlying adolescent SUD versus problematic use. Greater negative coupling between the SCN and ECN in adolescents with problematic substance use could underlie risk for future development of SUD or other mental health problems. Although we cannot infer directionality, hypoconnectivity within the insula in adolescents with SUD may indicate addiction-related alterations in interoceptive awareness or impairments in decision-making.

Cannabinoid use and self-injurious behaviours: A systematic review and meta-analysis

BACKGROUND

The increasing availability of high-potency cannabis-derived compounds and the use of synthetic cannabinoids may be responsible for severe side effects like cognitive impairment, psychosis or self-injurious behaviours (SIB). In particular, SIB like non-suicidal self-injury (NSSI) and deliberate self-harm (DSH) raise growing concern as a possible consequence of cannabis use. However, the research to date has not addressed the relationship between cannabinoid use and SIB systematically.

METHODS

We conducted a systematic review on PubMed up to March 2020, using search terms related to cannabinoids and SIB.

RESULTS

The search yielded a total of 440 abstracts. Of those, 37 studies published between 1995 and 2020 were eligible for inclusion. Cannabinoid use was significantly associated with SIB at the cross-sectional (OR=1.569, 95%CI [1.167-2.108]) and longitudinal (OR=2.569, 95%CI [2.207-3.256]) level. Chronic use, presence of mental disorders, depressive symptoms, emotional dysregulation and impulsive traits might further increase the likelihood of self-harm in cannabis users. Synthetic cannabinoids may trigger highly destructive SIB mainly through the psychotomimetic properties of these compounds.

CONCLUSION

Cannabinoid use was associated with an increased prevalence of self-injury and may act as a causative factor with a duration-dependent manner. Emotional regulation and behavioural impulsivity functions might crucially moderate this association. Future studies should further investigate the mechanisms underlying this association, while exploring potential therapeutic applications of substances modulating the endocannabinoid system.

Functional Impairment in Response to the COVID-19 Pandemic among Cannabis Users

BACKGROUND

The Coronavirus disease 2019 (COVID-19) pandemic has contributed to over 2 million deaths and hospitalization of many individuals worldwide. Although preliminary evidence suggests that cannabis use has increased during the pandemic, there has been little research on the impact of cannabis use on COVID-related psychological outcomes. Cannabis use among college students is associated with problematic psychosocial outcomes; thus, it follows that cannabis users during the pandemic may experience more functional impairment problems with daily living as a result of increased psychological distress from the pandemic and difficulty with regulating that distress.

METHODS

The current study tested whether cannabis use status was related to functional impairment in daily activities and whether this was due to difficulty with emotion regulation and COVID-related distress. The sample comprised of 727 (184 current cannabis users) young adults in Louisiana, a state that had some of the highest rates of COVID-19 deaths and infections in the U.S.

RESULTS

Cannabis use was related to greater functional impairment in daily activities and this relation was mediated by the sequential effects of difficulty with emotion regulation and COVID-related distress.

CONCLUSIONS

Results indicated that cannabis users during the COVID-19 pandemic are experiencing problematic psychosocial outcomes further highlighting the need for the development of interventions to help target COVID-related distress and improve psychosocial functioning during the pandemic.

Rt-fMRI neurofeedback-guided cognitive reappraisal training modulates amygdala responsivity in posttraumatic stress disorder

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We found neurofeedback-specific attenuation of amygdala responses.

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Trauma symptoms and the affective state improved in patients at one-month follow-up.

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Reduced amygdala responses were associated with improved well-being at follow-up.

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75% of individuals with PTSD used the learned strategies in daily life.

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Left lateral prefrontal cortex responses were reduced during neurofeedback training.

Background

Traumatic experiences are associated with neurofunctional dysregulations in key regions of the emotion regulation circuits. In particular, amygdala responsivity to negative stimuli is exaggerated while engagement of prefrontal regulatory control regions is attenuated. Successful application of emotion regulation (ER) strategies may counteract this disbalance, however, application of learned strategies in daily life is hampered in individuals afflicted by posttraumatic stress disorder (PTSD). We hypothesized that a single session of real-time fMRI (rtfMRI) guided upregulation of prefrontal regions during an emotion regulation task enhances self-control during exposure to negative stimuli and facilitates transfer of the learned ER skills to daily life.

Methods

In a cross-over design, individuals with a PTSD diagnosis after a single traumatic event (n = 20) according to DSM-IV-TR criteria and individuals without a formal psychiatric diagnosis (n = 21) underwent a cognitive reappraisal training. In randomized order, all participants completed two rtfMRI neurofeedback (NF) runs targeting the left lateral prefrontal cortex (lPFC) and two control runs without NF (NoNF) while using cognitive reappraisal to reduce their emotional response to negative scenes. During the NoNF runs, two %%-signs were displayed instead of the two-digit feedback (FB) to achieve a comparable visual stimulation. The project aimed at defining the clinical potential of the training according to three success markers: (1) NF induced changes in left lateral prefrontal cortex and bilateral amygdala activity during the regulation of aversive scenes compared to cognitive reappraisal alone (primary registered outcome), (2) associated changes on the symptomatic and behavioral level such as indicated by PTSD symptom severity and affect ratings, (3) clinical utility such as indicated by perceived efficacy, acceptance, and transfer to daily life measured four weeks after the training.

Results

In comparison to the reappraisal without feedback, a neurofeedback-specific decrease in the left lateral PFC (d = 0.54) alongside an attenuation of amygdala responses (d = 0.33) emerged. Reduced amygdala responses during NF were associated with symptom improvement (r = −0.42) and less negative affect (r = −0.63) at follow-up. The difference in symptom scores exceeds requirements for a minimal clinically important difference and corresponds to a medium effect size (d = 0.64). Importantly, 75% of individuals with PTSD used the strategies in daily life during a one-month follow-up period and perceived the training as efficient.

Conclusion

Our findings suggest beneficial effects of the NF training indicated by reduced amygdala responses that were associated with improved symptom severity and affective state four weeks after the NF training as well as patient-centered perceived control during the training, helpfulness and application of strategies in daily life. However, reduced prefrontal involvement was unexpected. The study suggests good tolerability of the training protocol and potential for clinical use in the treatment of PTSD.

Common and separable neural alterations in substance use disorders: A coordinate-based meta-analyses of functional neuroimaging studies in humans

Delineating common and separable neural alterations in substance use disorders (SUD) is imperative to understand the neurobiological basis of the addictive process and to inform substance‐specific treatment strategies. Given numerous functional MRI (fMRI) studies in different SUDs, a meta‐analysis could provide an opportunity to determine robust shared and substance‐specific alterations. The present study employed a coordinate‐based meta‐analysis covering fMRI studies in individuals with addictive cocaine, cannabis, alcohol, and nicotine use. The primary meta‐analysis demonstrated common alterations in primary dorsal striatal, and frontal circuits engaged in reward/salience processing, habit formation, and executive control across different substances and task‐paradigms. Subsequent sub‐analyses revealed substance‐specific alterations in frontal and limbic regions, with marked frontal and insula‐thalamic alterations in alcohol and nicotine use disorders respectively. Examining task‐specific alterations across substances revealed pronounced frontal alterations during cognitive processes yet stronger striatal alterations during reward‐related processes. Finally, an exploratory meta‐analysis revealed that neurofunctional alterations in striatal and frontal reward processing regions can already be determined with a high probability in studies with subjects with comparably short durations of use. Together the findings emphasize the role of dysregulations in frontostriatal circuits and dissociable contributions of these systems in the domains of reward‐related and cognitive processes which may contribute to substance‐specific behavioral alterations.

Oxytocin Differentially Modulates Amygdala Responses during Top-Down and Bottom-Up Aversive Anticipation

The ability to successfully regulate negative emotions such as fear and anxiety is vital for mental health. Intranasal administration of the neuropeptide oxytocin (OXT) has been shown to reduce amygdala activity but to increase amygdala-prefrontal cortex connectivity during exposure to threatening stimuli suggesting that it may act as an important modulator of emotion regulation. The present randomized, between-subject, placebo-controlled pharmacological study combines the intranasal administration of OXT with functional magnetic resonance imaging (fMRI) during an explicit emotion regulation paradigm in 65 healthy male participants to investigate the modulatory effects of OXT on both bottom-up and top-down emotion regulation. OXT attenuates the activation in the posterior insular cortex and amygdala during anticipation of top-down regulation of predictable threat stimuli in participants with high trait anxiety. In contrast, OXT enhances amygdala activity during the bottom-up anticipation of unpredictable threat stimuli in participants with low trait anxiety. OXT may facilitate top-down goal-directed attention by attenuating amygdala activity in high anxiety individuals, while promoting bottom-up attention/vigilance to unexpected threats by enhancing amygdala activity in low anxiety individuals. OXT may thus have the potential to promote an adaptive balance between bottom-up and top-down attention systems depending on an individual's trait anxiety level.

Stress-induced cortical dopamine response is altered in subjects at clinical high risk for psychosis using cannabis

Stress and cannabis use are risk factors for the development of psychosis. We have previously shown that subjects at clinical high risk for psychosis (CHR) exhibit a higher striatal dopamine response to stress compared with healthy volunteers (HV), with chronic cannabis use blunting this response. However, it is unknown if this abnormal dopamine response extends to the prefrontal cortex (PFC). Here, we investigated dorsolateral PFC (dlPFC) and medial PFC (mPFC) dopamine release using [¹¹ C]FLB457 positron emission tomography (PET) and a validated stress task. Thirty-three participants completed two PET scans (14 CHR without cannabis use, eight CHR regular cannabis users [CHR-CUs] and 11 HV) while performing a Sensory Motor Control Task (control scan) and the Montreal Imaging Stress Task (stress scan). Stress-induced dopamine release (ΔBP_ND ) was defined as percent change in D_2/3 receptor binding potential between both scans using a novel correction for injected mass of [¹¹ C]FLB457. ΔBP_ND was significantly different between groups in mPFC (F(2,30) = 5.40, .010), with CHR-CUs exhibiting lower ΔBP_ND compared with CHR (.008). Similarly, salivary cortisol response (ΔAUC_I ) was significantly lower in CHR-CU compared with CHR (F(2,29) = 5.08, .013; post hoc .018) and positively associated with ΔBP_ND . Furthermore, CHR-CUs had higher attenuated psychotic symptoms than CHR following the stress task, which were negatively associated with ΔBP_ND . Length of cannabis use was negatively associated with ΔBP_ND in mPFC when controlling for current cannabis use. Given the global trend to legalize cannabis, this study is important as it highlights the effects of regular cannabis use on cortical dopamine function in high-risk youth.

Targeting the endocannabinoid system: a predictive, preventive, and personalized medicine-directed approach to the management of brain pathologies

Cannabis-inspired medical products are garnering increasing attention from the scientific community, general public, and health policy makers. A plethora of scientific literature demonstrates intricate engagement of the endocannabinoid system with human immunology, psychology, developmental processes, neuronal plasticity, signal transduction, and metabolic regulation. Despite the therapeutic potential, the adverse psychoactive effects and historical stigma, cannabinoids have limited widespread clinical application. Therefore, it is plausible to weigh carefully the beneficial effects of cannabinoids against the potential adverse impacts for every individual. This is where the concept of "personalized medicine" as a promising approach for disease prediction and prevention may take into the account. The goal of this review is to provide an outline of the endocannabinoid system, including endocannabinoid metabolizing pathways, and will progress to a more in-depth discussion of the therapeutic interventions by endocannabinoids in various neurological disorders.

Balancing act: Neural correlates of affect dysregulation in youth depression and substance use - A systematic review of functional neuroimaging studies

Both depression and substance use problems have their highest incidence during youth (i.e., adolescence and emerging adulthood), and are characterized by emotion regulation deficits. Influential neurodevelopmental theories suggest that alterations in the function of limbic and frontal regions render youth susceptible to these deficits. However, whether depression and substance use in youth are associated with similar alterations in emotion regulation neural circuitry is unknown. In this systematic review we synthesized the results of functional magnetic resonance imaging (fMRI) studies investigating the neural correlates of emotion regulation in youth depression and substance use. Resting-state fMRI studies focusing on limbic connectivity were also reviewed. While findings were largely inconsistent within and between studies of depression and substance use, some patterns emerged. First, youth depression appears to be associated with exaggerated amygdala activity in response to negative stimuli; second, both depression and substance use appear to be associated with lower functional connectivity between the amygdala and prefrontal cortex during rest. Findings are discussed in relation to support for existing neurodevelopmental models, and avenues for future work are suggested, including studying neurodevelopmental trajectories from a network perspective.

Impaired cognitive performance under psychosocial stress in cannabis-dependent men is associated with attenuated precuneus activity

BACKGROUND

Deficient regulation of stress plays an important role in the escalation of substance use, addiction and relapse. Accumulating evidence suggests dysregulations in cognitive and reward-related processes and the underlying neural circuitry in cannabis dependence. However, despite the important regulatory role of the endocannabinoid system in the stress response, associations between chronic cannabis use and altered stress processing at the neural level have not been systematically examined.

METHODS

Against this background, the present functional MRI study examined psychosocial stress processing in cannabis-dependent men (n = 28) and matched controls (n = 23) using an established stress-induction paradigm (Montreal Imaging Stress Task) that combines computerized (adaptive) mental arithmetic challenges with social evaluative threat.

RESULTS

During psychosocial stress exposure, but not the no-stress condition, cannabis users demonstrated impaired performance relative to controls. In contrast, levels of experienced stress and cardiovascular stress responsivity did not differ from controls. Functional MRI data revealed that stress-induced performance deteriorations in cannabis users was accompanied by decreased precuneus activity and increased connectivity of this region with the superior frontal gyrus.

LIMITATIONS

Only male cannabis-dependent users were examined; the generalizability in female users remains to be determined.

CONCLUSION

Together, the present findings provide first evidence for exaggerated stress-induced cognitive performance deteriorations in cannabis users. The neural data suggest that deficient stress-related recruitment of the precuneus may be associated with the deterioration of performance at the behavioural level.

Modeling the Comorbidity of Cannabis Abuse and Conduct Disorder/Conduct Problems from a Cognitive Neuroscience Perspective

Objective: A cognitive neuroscience perspective seeks to understand behavior, in this case the comorbidity of cannabis abuse and conduct disorder/conduct problems, in terms of dysfunction in cognitive processes underpinned by neural processes. The goal of this review is to articulate a cognitive neuroscience account of this comorbidity. Methods: Literature on the following issues will be reviewed: (i) the longitudinal relationship between cannabis abuse and conduct disorder/conduct problems (CD/CP); (ii) the extent to which there are genetic and environmental (specifically maltreatment) factors that underpin this relationship; (iii) forms of neurocognitive function that are reported dysfunctional in CD/CP and also, when dysfunctional, appear to be risk factors for future cannabis abuse; and (iv) the extent to which cannabis abuse may further compromise these systems leading to increased future abuse and greater conduct problems. Results: CD/CP typically predate cannabis abuse. There appear to be shared genetic factors that contribute to the relationship between CD/CP and cannabis abuse. Moreover, trauma exposure increases risk for both cannabis abuse and CP/CD. One form of neurocognitive dysfunction, response disinhibition, that likely exacerbates the symptomatology of many individuals with CD also appears to increase the risk for cannabis abuse. The literature with respect to other forms of neurocognitive dysfunction remains inconclusive. Conclusions: Based on the literature, a causal model of the comorbidity of cannabis abuse and CD/CP is developed.

Altered Effective Connectivity of Central Autonomic Network in Response to Negative Facial Expression in Adults With Cannabis Use Disorder

BACKGROUND

Cannabis use is associated with an increased risk of stress-related adverse cardiovascular events. Because brain regions of the central autonomic network largely overlap with brain regions related to the neural response to emotion and stress, the central autonomic network may mediate the autonomic response to negative emotional stimuli. We aimed to obtain evidence to determine whether neural connectivity of the central autonomic network is altered in individuals with cannabis use disorder (CUD) when they are exposed to negative emotional stimuli.

METHODS

Effective (directional) connectivity (EC) analysis using dynamic causal modeling was applied to functional magnetic resonance imaging data acquired from 23 subjects with CUD and 23 control subjects of the Human Connectome Project while they performed an emotional face-matching task with interleaving periods of negative-face (fearful/angry) and neutral-shape stimuli. The EC difference (modulatory change) was measured during the negative-face trials relative to the neutral-shape trials.

RESULTS

The CUD group was similar to the control group in nonimaging measures and brain activations but showed greater modulatory changes in left amygdala to hypothalamus EC (positively associated with Perceived Stress Scale score), right amygdala to bilateral fusiform gyri ECs (positively associated with Perceived Stress Scale score), and left ventrolateral prefrontal cortex to bilateral fusiform gyri ECs (negatively associated with Perceived Stress Scale score).

CONCLUSIONS

Left amygdala to hypothalamus EC and right amygdala to bilateral fusiform gyri ECs are possibly part of circuits underlying the risk of individuals with CUD to stress-related disorders. Correspondingly, left ventrolateral prefrontal cortex to bilateral fusiform gyri ECs are possibly part of circuits reflecting a protective mechanism.

Emotion Dysregulation Moderates the Association Between Stress and Problematic Cannabis Use

Background: Research suggests emotion dysregulation is a transdiagnostic risk factor for substance use and addiction and that stress may lead to problematic cannabis use. Thus, the current study examines how emotion dysregulation moderates the associations between stress (stressful life events and perceived stress) and problematic cannabis use. Methods: Eight hundred and fifty-two adults reporting any lifetime cannabis use completed an anonymous online survey. Participants completed a brief demographic questionnaire and were asked to report their past 30-day use of cannabis, alcohol, nicotine, and illicit substances. Problematic cannabis use (via the Marijuana Problem Scale), emotion dysregulation (via the Difficulties in Emotion Regulation Scale), perceived stress (via the Perceived Stress Scale), and stressful life events (via the Holmes-Rahe Life Stress Inventory) were assessed. Hierarchical multiple linear regressions were conducted. Results: Findings indicate that when examining the moderating role of emotion dysregulation, more stressful life events and less perceived stress were associated with more severe problematic cannabis use, and these associations were stronger at higher levels of emotion dysregulation. Conclusions: These results demonstrate a strong step toward understanding how emotion dysregulation moderates the relationship between stress and problematic cannabis use; however, longitudinal studies are needed to determine directionality of effects. Overall, these results suggest the importance of examining emotion dysregulation as a moderator of both stressful life events and stress perception as they relate to problematic cannabis use.

Violence and Cannabis Use: A Focused Review of a Forgotten Aspect in the Era of Liberalizing Cannabis

There has been a shift surrounding societal and legal perspectives on cannabis reflecting changing public attitudes towards the perceived safety and social acceptability of cannabis use. With cannabis liberalization internationally, the focus of most cannabis-related harms has been on effects with users themselves. Harm-to-others including injuries from violence have nevertheless been unfortunately largely overlooked. While studies remain heterogeneous, there is meta-analytical evidence pointing towards an association. The aims of this focused review are two-fold: (I) review the evidence from meta-analyses on the association between cannabis and violence; and (II) provide an overview of possible mechanisms relating cannabis use to violence. First, evidence from meta-analytical studies in youths, intimate partners, and individuals with severe mental disorders have shown that there is a global moderate association between cannabis use and violence, which is stronger in the latter more at-risk population. Preliminary data has even highlighted a potential dose-response relationship with larger effects in more frequent users. Although of importance, this subject has remained essentially forgotten as a public health concern. While literature remains inconclusive, data has suggested potential increases in cannabis use following liberalization policies. This may increase violent outcomes if the effect is directly related to the use of cannabis by means of its psychophysiological modifications. However, for the moment, the mechanisms associating cannabis use and violence remain to be clearly resolved. Considering the recency of policy changes on cannabis, further methodologically sound research using longitudinal designs should examine the effects that cannabis use may have on different forms of violence and the trends that emerge, while evaluating the effects of possible confounding factors (e.g. other substance use). In addition, as evidence-based research from meta-analyses have shown that cannabis use is associated with violence, measures must be taken to mitigate the risks.

Alcohol use disorder and cannabis use disorder symptomatology in adolescents are differentially related to dysfunction in brain regions supporting face processing

Despite extensive behavioral evidence of impairments in face processing and expression recognition in adults with alcohol or cannabis use disorders (AUD/CUD), neuroimaging findings have been inconsistent. Moreover, relatively little work has examined the relationship of AUD or CUD symptoms with face or expression processing within adolescents. Given the high prevalence of alcohol and cannabis use during adolescence, understanding how these usage behaviors interact with neural mechanisms supporting face and expression processing could have important implications for youth social and emotional functioning. In this study, adolescents (N = 104) responded to morphed fearful and happy expressions during fMRI and their level of AUD and/or CUD symptoms were related to the BOLD response data. We found that AUD and CUD symptom severity were both negatively related to responses to faces generally. However, whereas this relationship was shown for AUD within ventromedial prefrontal cortex and lingual gyrus, it was shown for CUD within rostromedial prefrontal cortex including anterior cingulate cortex. Additionally, AUD symptom levels were associated with differential responses within medial temporal pole and inferior parietal lobule as a function of expression. These results have potential implications for understanding the social and emotional functioning of adolescents with AUD and CUD symptoms.

Neuroimaging Impaired Response Inhibition and Salience Attribution in Human Drug Addiction: A Systematic Review

The impaired response inhibition and salience attribution (iRISA) model proposes that impaired response inhibition and salience attribution underlie drug seeking and taking. To update this model, we systematically reviewed 105 task-related neuroimaging studies (n > 15/group) published since 2010. Results demonstrate specific impairments within six large-scale brain networks (reward, habit, salience, executive, memory, and self-directed networks) during drug cue exposure, decision making, inhibitory control, and social-emotional processing. Addicted individuals demonstrated increased recruitment of these networks during drug-related processing but a blunted response during non-drug-related processing, with the same networks also being implicated during resting state. Associations with real-life drug use, relapse, therapeutic interventions, and the relevance to initiation of drug use during adolescence support the clinical relevance of the results. Whereas the salience and executive networks showed impairments throughout the addiction cycle, the reward network was dysregulated at later stages of abuse. Effects were similar in alcohol, cannabis, and stimulant addiction.

Threat Responsiveness as a Function of Cannabis and Alcohol Use Disorder Severity

Objective: Two of the most commonly abused substances by adolescents in the United States are alcohol and cannabis, both of which are associated with adverse medical and psychiatric outcomes throughout the lifespan. Both are assumed to impact the development of emotional processing although findings on the direction of this impact have been mixed. Preclinical animal work and some functional magnetic resonance imaging (fMRI) work with humans have suggested cannabis use disorder (CUD) and alcohol use disorder (AUD) are associated with increased threat responsiveness. However, other fMRI work has indicated CUD/AUD are associated with diminished threat responsiveness. In this study, we report on a study examining the relationship of severity of CUD/AUD and threat responsiveness in an adolescent population. Methods: The study involved 87 (43 male) adolescents with varying levels of CUD/AUD symptomatology (N = 45 above clinical cutoffs for CUD or AUD). They were scanned with fMRI during a looming threat task that involved images of threatening and neutral human faces or animals that appeared to be either looming or receding. Results: Increasing levels of CUD symptomatology were associated with decreased responding to looming stimuli within regions, including rostral frontal and fusiform gyrus as well as the amygdala. There were no relationships with AUD symptomatology. Conclusions: These data indicate that CUD in particular is associated with a decrease in responsiveness to the looming threat cue possibly relating to the putative neurotoxic impact of cannabis abuse.

Investigating the psychometric properties of the Suicide Stroop Task

Behavioral measures are increasingly used to assess suicidal thoughts and behaviors. Some measures, such as the Suicide Stroop Task, have yielded mixed findings in the literature. An understudied feature of these behavioral measures has been their psychometric properties, which may affect the probability of detecting significant effects and reproducibility. In the largest investigation of its kind, we tested the internal consistency and concurrent validity of the Suicide Stroop Task in its current form, drawing from seven separate studies (N = 875 participants, 64% female, aged 12 to 81 years). Results indicated that the most common Suicide Stroop scoring approach, interference scores, yielded unacceptably low internal consistency (rs = -.09-.13) and failed to demonstrate concurrent validity. Internal consistency coefficients for mean reaction times (RTs) to each stimulus type ranged from rs = .93-.94. All scoring approaches for suicide-related interference demonstrated poor classification accuracy (AUCs = .52-.56) indicating that scores performed near chance in their ability to classify suicide attempters from nonattempters. In the case of mean RTs, we did not find evidence for concurrent validity despite our excellent reliability findings, highlighting that reliability does not guarantee a measure is clinically useful. These results are discussed in the context of the wider implications for testing and reporting psychometric properties of behavioral measures in mental health research. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Typology of cannabis use among adults: A latent class approach to risk and protective factors

BACKGROUND

Cannabis is among the most widely used substances worldwide. The United States has seen an increase in the number of adult daily cannabis users and in the number of adults diagnosed with cannabis use disorder. However, little work has examined patterns of use or unique subgroups of adult cannabis users, which may be useful in developing targeted treatment interventions for problematic cannabis users. Therefore, the current study used latent profile analysis to identify whether cannabis users can be categorized across distinct subgroups of adult users.

METHOD

The sample included 374 current cannabis using adults (64.2% Male; M_age = 32.6). Cannabis use frequency, quantity, and related problems were used to differentiate subgroups. Further, age, race, emotion dysregulation, affect, anxiety sensitivity, other substance use, and motives for cannabis use were examined as class correlates.

RESULTS

Results supported five unique classes of cannabis users, generally ranging from light, infrequent users with few problems to heavy, frequent users with more problems. Additionally, race, negative affectivity, anxiety sensitivity, emotion regulation, cannabis use motives, and alcohol use emerged as unique predictors of class membership. The current findings substantiate past work for heterogeneous latent classes that underlie the larger cannabis using population, however, this study provides novel evidence for subgroups of adult users.

CONCLUSION

The identification of different classes of cannabis users may inform future treatment interventions, and ultimately, lead to the development of personalized treatments for each class based on correlates of group membership.

Real-Time Functional Connectivity-Informed Neurofeedback of Amygdala-Frontal Pathways Reduces Anxiety

BACKGROUND

Deficient emotion regulation and exaggerated anxiety represent a major transdiagnostic psychopathological marker. On the neural level these deficits have been closely linked to impaired, yet treatment-sensitive, prefrontal regulatory control over the amygdala. Gaining direct control over these pathways could therefore provide an innovative and promising intervention to regulate exaggerated anxiety. To this end the current proof-of-concept study evaluated the feasibility, functional relevance and maintenance of a novel connectivity-informed real-time fMRI neurofeedback training.

METHODS

In a randomized crossover sham-controlled design, 26 healthy subjects with high anxiety underwent real-time fMRI-guided neurofeedback training to enhance connectivity between the ventrolateral prefrontal cortex (vlPFC) and the amygdala (target pathway) during threat exposure. Maintenance of regulatory control was assessed after 3 days and in the absence of feedback. Training-induced changes in functional connectivity of the target pathway and anxiety ratings served as primary outcomes.

RESULTS

Training of the target, yet not the sham control, pathway significantly increased amygdala-vlPFC connectivity and decreased levels of anxiety. Stronger connectivity increases were significantly associated with higher anxiety reduction on the group level. At the follow-up, volitional control over the target pathway was maintained in the absence of feedback.

CONCLUSIONS

The present results demonstrate for the first time that successful self-regulation of amygdala-prefrontal top-down regulatory circuits may represent a novel intervention to control anxiety. As such, the present findings underscore both the critical contribution of amygdala-prefrontal circuits to emotion regulation and the therapeutic potential of connectivity-informed real-time neurofeedback.

Cue Reactivity in the Ventral Striatum Characterizes Heavy Cannabis Use, Whereas Reactivity in the Dorsal Striatum Mediates Dependent Use

BACKGROUND

Animal models of addiction suggest that the transition from incentive-driven drug use to habitual and ultimately compulsive drug use is mediated by a shift from ventral to dorsal striatal cue control over drug seeking. Previous studies in human cannabis users reported elevated trait impulsivity and neural cue reactivity in striatal circuits; however, these studies were not able to separate addiction-related from exposure-related adaptations.

METHODS

To differentiate the adaptive changes, the current functional magnetic resonance imaging study examined behavioral and neural cue reactivity in dependent (n = 18) and nondependent (n = 20) heavy cannabis users and a nonusing reference group (n = 44).

RESULTS

Irrespective of dependence status, cannabis users demonstrated elevated trait impulsivity as well as increased ventral striatal reactivity and striatal frontal coupling in response to drug cues. Dependent users selectively exhibited dorsal striatal reactivity and decreased striatal limbic coupling during cue exposure. An exploratory analysis revealed that higher ventral caudate neural cue reactivity was associated with stronger cue-induced arousal and craving in dependent users, whereas this pattern was reversed in nondependent users.

CONCLUSIONS

Taken together, the current findings suggest that exaggerated responses of the ventral striatal reward system may promote excessive drug use in humans, whereas adaptations in dorsal striatal systems engaged in habit formation may promote the transition to addictive use.

Interactions between recreational cannabis use and cognitive function: lessons from functional magnetic resonance imaging

Cannabis use is becoming increasingly popular as a growing number of states pass legislation to legalize cannabis and cannabis-derived products for recreational and/or medical purposes. Given the widespread use of cannabis, it is critical to understand the neural consequences related to cannabis use. In this review, we focus on evidence from functional magnetic resonance imaging studies that document acute and residual alterations in brain function during tasks spanning a variety of cognitive domains: executive function, attention and working memory, memory, motor skills, error monitoring, and reward and affective processing. Although it is clear that cannabis affects brain function, the findings are somewhat inconsistent; variables that potentially affect study outcomes are outlined, including a discussion of the impact of chronological age and age of cannabis onset as well as length of abstinence at the time of assessment, which are important considerations when measuring cannabis use patterns. Inherent differences between recreational/adult cannabis use versus use for medical purposes are also discussed, given their importance to public policy decisions.

The neuropsychopharmacology of cannabis: A review of human imaging studies

The laws governing cannabis are evolving worldwide and associated with changing patterns of use. The main psychoactive drug in cannabis is Δ⁹-tetrahydrocannabinol (THC), a partial agonist at the endocannabinoid CB₁ receptor. Acutely, cannabis and THC produce a range of effects on several neurocognitive and pharmacological systems. These include effects on executive, emotional, reward and memory processing via direct interactions with the endocannabinoid system and indirect effects on the glutamatergic, GABAergic and dopaminergic systems. Cannabidiol, a non-intoxicating cannabinoid found in some forms of cannabis, may offset some of these acute effects. Heavy repeated cannabis use, particularly during adolescence, has been associated with adverse effects on these systems, which increase the risk of mental illnesses including addiction and psychosis. Here, we provide a comprehensive state of the art review on the acute and chronic neuropsychopharmacology of cannabis by synthesizing the available neuroimaging research in humans. We describe the effects of drug exposure during development, implications for understanding psychosis and cannabis use disorder, and methodological considerations. Greater understanding of the precise mechanisms underlying the effects of cannabis may also give rise to new treatment targets.

Shifted balance of dorsal versus ventral striatal communication with frontal reward and regulatory regions in cannabis-dependent males

The transition from voluntary to addictive behavior is characterized by a loss of regulatory control in favor of reward driven behavior. Animal models indicate that this process is neurally underpinned by a shift in ventral-dorsal striatal control of behavior; however, this shift has not been directly examined in humans. The present resting state functional magnetic resonance imaging (fMRI) study employed a two-step approach to: (a) precisely map striatal alterations using a novel, data-driven network classification strategy combining intrinsic connectivity contrast with multivoxel pattern analysis and, (b) to determine whether a ventral to dorsal striatal shift in connectivity with reward and regulatory control regions can be observed in abstinent (28 days) male cannabis-dependent individuals (n = 24) relative to matched controls (n = 28). Network classification revealed that the groups can be reliably discriminated by global connectivity profiles of two striatal regions that mapped onto the ventral (nucleus accumbens) and dorsal striatum (caudate). Subsequent functional connectivity analysis demonstrated a relative shift between ventral and dorsal striatal communication with fronto-limbic regions that have been consistently involved in reward processing (rostral anterior cingulate cortex [ACC]) and executive/regulatory functions (dorsomedial prefrontal cortex [PFC]). Specifically, in the cannabis-dependent subjects, connectivity between the ventral striatum with the rostral ACC increased, whereas both striatal regions were uncoupled from the regulatory dorsomedial PFC. Together, these findings suggest a shift in the balance between dorsal and ventral striatal control in cannabis dependence. Similar changes have been observed in animal models and may promote the loss of control central to addictive behavior.