Cognitive Functioning of Adolescent and Young Adult Cannabis Users in the Philadelphia Neurodevelopmental Cohort
J. Scott, Daniel H. Wolf, Monica E. Calkins, Emily C. Bach, Jennifer Weidner, Kosha Ruparel, Tyler M Moore, Jason D. Jones, Chad Jackson, Raquel E. Gur, R. Gur
Psychology of Addictive Behaviors April 17, 2017 DOI: 10.1037/adb0000268 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Longitudinal Peer reviewed |
|---|---|
| Sample size | 4,568 |
| Population | Adolescents and young adults ages 14–21 from the Philadelphia Neurodevelopmental Cohort |
| Topics | Cannabis |
| Key findings | Frequent cannabis use in adolescence, but not young adulthood, was associated with worse executive control performance compared with non-use, and earlier initiation was linked to worse executive control in occasional users. However, occasional users performed better than non-users on executive control, memory, and social cognition. The authors conclude that relationships between cannabis use and cognition in youth are complex and require longitudinal study. |
Abstract
Cannabis use in youth is rising and has been linked to deficits in cognitive functioning. However, cognitive findings have primarily been based on small samples of users seeking treatment, and few studies have evaluated cognition in occasional cannabis users. Here, we examined 4,568 adolescents and young adults (ages 14–21 years) drawn from the Philadelphia Neurodevelopmental Cohort, a prospective, population-based study. Participants were classified as cannabis Non-Users (n = 3,401), Occasional Users (twice per week or less; n = 940), or Frequent Users (>3 times per week; n = 227). Mixed-model analyses examined main effects of cannabis use and interactions between age and cannabis use on cognitive functioning. There was a significant interaction between cannabis group and age such that adolescent (but not young adult) Frequent Users performed worse than Non-Users on measures of executive control (p = .002). Earlier age of cannabis use was associated with worse performance in executive control in Occasional Users (p = .04). Unexpectedly, Occasional Users exhibited better executive control, memory, and social cognition than Non-Users (ps < .05). Although mild executive control deficits in adolescent frequent users and a relation between early cannabis initiation and cognitive performance are partially consistent with prior research, cognitive deficits were not found in other hypothesized domains in this community-based sample. Moreover, occasional cannabis users displayed equivalent or even slightly better executive control, social–cognitive, and memory abilities compared with nonusers, suggesting complex relationships between cannabis use and cognition in youth. Longitudinal studies with community samples are needed to identify variables affecting risk and resilience to cognitive deficits associated with cannabis.
Comparable studies
Other observational and cohort studies on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| High-potency cannabis and the risk of psychosis People with first episode of psychosis and healthy controls from the local population | 2009 | Case-control study | n = 454 |
| Ayahuasca-Assisted Therapy for Addiction: Results from a Preliminary Observational Study in Canada Rural aboriginal population | 2013 | Observational study | |
| Impaired cognitive performance in drug free users of recreational ecstasy (MDMA) Otherwise healthy young people | 2000 | Observational | |
| Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study Individuals from the general population in Germany aged 14-24 at baseline | 2011 | Observational cohort | n = 1,923 |
| Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases Patients treated for cannabis-induced psychotic symptoms in Denmark between 1994 and... | 2005 | Observational cohort | n = 535 |
Citations in the library
Cited by 12
- Age-related differences in the impact of cannabis use on the brain and cognition: a systematic review European Archives of Psychiatry and Clinical Neuroscience January 24, 2019
- The CannTeen study: verbal episodic memory, spatial working memory, and response inhibition in adolescent and adult cannabis users and age-matched controls Psychopharmacology April 29, 2022
- Cannabis use and glutamate across the psychosis spectrum: in vivo evidence from 7T proton magnetic resonance spectroscopy Molecular Psychiatry June 27, 2026
- The CannTeen Study: Verbal Episodic Memory, Spatial Working Memory, and Response Inhibition in Adolescent and Adult Cannabis Users and Age-Matched Controls PRE-PRINT February 18, 2022
- Regulation of neural connectivity and oscillations by cannabinoids: A review. Neuroscience & Biobehavioral Reviews September 7, 2026
and 7 more in the library
Cites 11
- Cannabis use before age 15 and subsequent executive functioning The British Journal of Psychiatry May 31, 2011
- Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases The British Journal of Psychiatry November 30, 2005
- Smoked Cannabis' Psychomotor and Neurocognitive Effects in Occasional and Frequent Smokers Journal of Analytical Toxicology March 4, 2015
- Effects of cannabis on the adolescent brain. Current Pharmaceutical Design 2014
- Impulsivity, attention, memory, and decision-making among adolescent marijuana users. Psychopharmacology March 2013
and 6 more in the library