Project ID NS-MH2023_13


Co Supervisor 1A IoPPN/Addictions & Addictions CAGWebsite

Co Supervisor 1B IoPPN/PsychologyWebsite

Additional Supervisor Ted Barker, Ed Chesney

Understanding the biopsychosocial mechanisms underpinning the development of and recovery from adolescent cannabis addiction

Adolescents are thought to be more vulnerable to the harmful effects of cannabis than adults. Adolescents are reliably at a greater risk of developing cannabis use disorder (CUD) than adults. Cannabis addiction is the leading cause of <18-year-olds seeking drug treatment in the UK (>75% of cases). However, the mechanisms underpinning this greater risk of CUD and the most effective ways to treat adolescent CUD are unknown.

Study 1 (Year 1): Meta-analysis. Empirically quantify: (1) the augmented risk to CUD in adolescence; (2) predictors of adolescent CUD development.

Study 2 (Year 1 & 2): Longitudinal data analysis of existing MRC-funded ‘CannTeen’ data set (n=274), using multilevel modelling. Test predictors of CUD identified in meta-analysis, and examine fMRI-derived, urinary cannabinoid, epigenetic, and cognitive predictors of adolescent CUD. See methods (video):

Study 3 (Years 2 & 3): A cannabis withdrawal and app-aided quit attempt study in daily adolescent and adult cannabis users. Participants randomised to a quit-weed app or control app; outcomes measured by ecological momentary assessment. Test: (1) if adolescents differ from adults in their responses to THC abstinence; (2) if the quit-weed app is effective; (3) predictors of quit success.

Collaborate with addiction clinicians in SLaM to ensure clinical validity.
Work with a PPI group made up of adolescents who use cannabis.
Inform drug education and harm reduction strategies.

Techniques: meta-analysis, longitudinal data analysis, multilevel modelling, fMRI, epigenetics, randomised controlled trial, ecological momentary assessment, apps

Collaborators: Professor Ted Barker (3rd supervisor, adolescent development expert), Dr Ed Chesney (psychiatrist with cannabis expertise), Dr Matt Wall (fMRI expert)

Representative Publications

Lawn, W., Mokrysz, C., Lees, R., Trinci, K., Petrilli, K., Skumlien, M., … & Curran, V. (2022). The CannTeen Study: Cannabis use disorder, depression, anxiety, and psychotic-like symptoms in adolescent and adult cannabis users and age-matched controls. Journal of Psychopharmacology

Cunningham, J.A., Schell, C., Bertholet, N., Wardell, J.D., Quilty, L.C., Agic, B., & Godinho, A. (2021). Online personalized feedback intervention to reduce risky cannabis use. Randomized controlled trial. Internet Interventions. 26, 100484.

Takahashi, Y., Yamagata, S., Ritchie, S. J., Barker, E. D., & Ando, J. (2021). Etiological pathways of depressive and anxiety symptoms linked to personality traits: A genetically-informative longitudinal study. Journal of Affective Disorders, 291, 261-269.