Cannabis Use, Age of Initiation, and Neurocognitive Performance: Findings from a Large Sample of Heavy Drinking Emerging Adults

Randomized controlled internal pilot trial of a diversion programme for adolescents in police custody who possess illicit substances

BACKGROUND

Adolescents involved in criminal proceedings are significantly more likely to re-offend than a similar population diverted away from criminal justice. Adolescents who use substances and offend are at higher risk of experiencing negative social, psychological and physical problems that often persist into adulthood. There is some evidence that brief interventions combined with appropriate psychoeducation may be effective in reducing adolescent substance use.

METHODS

Prospective two-armed, individually randomized internal pilot randomized controlled trial (RCT) with follow-up at 6 months. Young people across three police forces-Kent, Cornwall and Sefton-arrested in possession of class B or C illicit substances were randomly allocated to receive the ReFrame intervention or business as usual. In total, 102 participants were eligible of whom 76 consented and 73 were followed up at 6 months. Outcomes addressed offending behaviour, frequency of substance use, wellbeing and mental health. The study was conducted between February and December 2022.

RESULTS

All progression criteria were met, 80% of those eligible consented, 96% adhered to their allocated treatment and 88% were followed up at the primary endpoint.

CONCLUSIONS

The feasibility of conducting the pilot trial was a success and it will now proceed to a definitive RCT.

Leveraging related health phenotypes for polygenic prediction of impulsive choice, impulsive action, and impulsive personality traits in 1534 European ancestry community adults

Impulsivity refers to a number of conceptually related phenotypes reflecting self-regulatory capacity that are considered promising endophenotypes for mental and physical health. Measures of impulsivity can be broadly grouped into three domains, namely, impulsive choice, impulsive action, and impulsive personality traits. In a community-based sample of ancestral Europeans (n = 1534), we conducted genome-wide association studies (GWASs) of impulsive choice (delay discounting), impulsive action (behavioral inhibition), and impulsive personality traits (UPPS-P), and evaluated 11 polygenic risk scores (PRSs) of phenotypes previously linked to self-regulation. Although there were no individual genome-wide significant hits, the neuroticism PRS was positively associated with negative urgency (adjusted R²  = 1.61%, p = 3.6 × 10^-7 ) and the educational attainment PRS was inversely associated with delay discounting (adjusted R²  = 1.68%, p = 2.2 × 10^-7 ). There was also evidence implicating PRSs of attention-deficit/hyperactivity disorder, externalizing, risk-taking, smoking cessation, smoking initiation, and body mass index with one or more impulsivity phenotypes (adjusted R² s: 0.35%-1.07%; FDR adjusted ps = 0.05-0.0006). These significant associations between PRSs and impulsivity phenotypes are consistent with established genetic correlations. The combined PRS explained 0.91%-2.46% of the phenotypic variance for individual impulsivity measures, corresponding to 8.7%-32.5% of their reported single-nucleotide polymorphism (SNP)-based heritability, suggesting a non-negligible portion of the SNP-based heritability can be recovered by PRSs. These results support the predictive validity and utility of PRSs, even derived from related phenotypes, to inform the genetics of impulsivity phenotypes.

A multicomponent psychosocial intervention to reduce substance use by adolescents involved in the criminal justice system: the RISKIT-CJS RCT

Background

Substance use and offending are related in the context of other disinhibitory behaviours. Adolescents involved in the criminal justice system constitute a particularly vulnerable group, with a propensity to engage in risky behaviour that has long-term impact on their future health and well-being. Previous research of the RISKIT programme provided evidence of a potential effect in reducing substance use and risky behaviour in adolescents.

Objectives

To evaluate the clinical effectiveness and cost-effectiveness of a multicomponent psychosocial intervention compared with treatment as usual in reducing substance use for substance-using adolescents involved in the criminal justice system.

Design

A mixed-methods, prospective, pragmatic, two-arm, randomised controlled trial with follow-up at 6 and 12 months post randomisation.

Setting

The study was conducted across youth offending teams, pupil referral units and substance misuse teams across four areas of England (i.e. South East, London, North West, North East).

Participants

Adolescents aged between 13 and 17 years (inclusive), recruited between September 2017 and June 2020.

Interventions

Participants were randomised to treatment as usual or to treatment as usual in addition to the RISKIT-Criminal Justice System (RISKIT-CJS) programme. The RISKIT-CJS programme was a multicomponent intervention and consisted of two individual motivational interviews with a trained youth worker (lasting 45 minutes each) and two group sessions delivered over half a day on consecutive weeks.

Main outcome measures

At 12 months, we assessed per cent days abstinent from substance use over the previous 28 days. Secondary outcome measures included well-being, motivational state, situational confidence, quality of life, resource use and fidelity of interventions delivered.

Results

A total of 693 adolescents were assessed for eligibility, of whom 505 (73%) consented. Of these, 246 (49%) were allocated to the RISKIT-CJS intervention and 259 (51%) were allocated to treatment as usual only. At month 12, the overall follow-up rate was 57%: 55% in the RISKIT-CJS arm and 59% in the treatment-as-usual arm. At month 12, we observed an increase in per cent days abstinent from substances in both arms of the study, from 61% to 85%, but there was no evidence that the RISKIT-CJS intervention was superior to treatment as usual. A similar pattern was observed for secondary outcomes. The RISKIT-CJS intervention was not found to be any more cost-effective than treatment as usual. The qualitative research indicated that young people were positive about learning new skills and acquiring new knowledge. Although stakeholders considered the intervention worthwhile, they expressed concern that it came too late for the target population.

Limitations

Our original aim to collect data on offences was thwarted by the onset of the COVID-19 pandemic, and this affected both the statistical and economic analyses. Although 214 (87%) of the 246 participants allocated to the RISKIT-CJS intervention attended at least one individual face-to-face session, 98 (40%) attended a group session and only 47 (19%) attended all elements of the intervention.

Conclusions

The RISKIT-CJS intervention was no more clinically effective or cost-effective than treatment as usual in reducing substance use among adolescents involved in the criminal justice system.

Future research

The RISKIT-CJS intervention was considered more acceptable, and adherence was higher, in pupil referral units and substance misuse teams than in youth offending teams. Stakeholders in youth offending teams thought that the intervention was too late in the trajectory for their population.

Trial registration

This trial is registered as ISRCTN77037777.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 11, No. 3. See the NIHR Journals Library website for further project information.

Prescribing Stimulants for Children and Adolescents With Attention-Deficit/Hyperactivity Disorder and Co-occurring Cannabis Use: Considerations for Managing a Clinical Dilemma

Attention-deficit/hyperactivity disorder (ADHD) is highly prevalent in the pediatric population, with 11% of children and adolescents having ever been diagnosed with the disorder.¹ The management of ADHD in the setting of co-occurring cannabis use, which is more prevalent in adolescents with ADHD than in the general population, is an increasingly common dilemma facing clinicians, in part due to recent changes in social acceptability, access, usage, and state-level legal status of cannabis.² Clinicians face several considerations, including the following: the confounding effects of cannabis use on assessment and management of ADHD symptoms; the potential reduction in risk of substance use when ADHD symptoms are well managed; and the increased risk of misuse and diversion of stimulants in patients with ongoing cannabis use.².

How do cannabis users mentally travel in time? Evidence from an fMRI study of episodic future thinking

RATIONALE

Episodic future thinking (EFT) is a cognitive function that allows individuals to imagine novel experiences that may happen in the future. Prior studies show that EFT is impaired in different groups of substance users. However, there is no evidence regarding the neurobiological mechanisms of EFT in cannabis users.

OBJECTIVES

We aimed to compare brain activations of regular cannabis users and non-using controls during an EFT fMRI task. Exploratory analyses were also conducted to investigate the association between EFT and cannabis use variables (e.g., duration of use, age onset, frequency of use).

METHODS

Twenty current cannabis users and 22 drug-naïve controls underwent an fMRI scanning session while completing a task involving envisioning future-related events and retrieval of past memories as a control condition. The EFT fMRI task was adapted from the autobiographical interview and composed of 20 auditory cue sentences (10 cues for past and 10 cues for future events). Participants were asked to recall a past or generate a future event, in response to the cues, and then rate their vividness after each response.

RESULTS

We found that cannabis users compared to non-user controls had lower activation within the cerebellum, medial and superior temporal gyrus, lateral occipital cortex, and occipital fusiform gyrus while envisioning future events. Cannabis users rated the vividness of past events significantly lower than non-users (P < 0.005). There were marginal group differences for rating the vividness of future events (P = 0.052). Significant correlations were also found between the medial and superior temporal gyrus activities and behavioral measures of EFT and episodic memory.

CONCLUSIONS

Cannabis users, compared to drug-naïve controls, have lower brain activation in EFT relevant regions. Thus, any attempts to improve aberrant EFT performance in cannabis users may benefit from EFT training.