Are adolescents more vulnerable to the harmful effects of cannabis than adults? A placebo-controlled study in human males
Claire Mokrysz, Tom P. Freeman, Saana M. Korkki, Kirsty Griffiths, Helen Valerie Curran
Translational Psychiatry November 29, 2016 DOI: 10.1038/tp.2016.225 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Placebo-controlled, double-blind cross-over study Peer reviewed |
|---|---|
| Sample size | 40 |
| Population | Male cannabis users: 20 adolescents aged 16-17 years and 20 adults aged 24-28 years |
| Topics | Cannabis |
| Citations | 111 |
| Key points | On active cannabis, adolescents reported feeling less stoned and fewer psychotomimetic symptoms than adults, while adults showed greater anxiety, reduced alertness, and more impaired spatial working memory reaction time and delayed prose recall. Adolescents instead showed impaired response inhibition accuracy and, after dosing, wanted more cannabis regardless of active or placebo, unlike adults. The authors argue these contrasting profiles of adolescent resilience and vulnerability may contribute to escalated cannabis use by adolescents. |
Abstract
Preclinical research demonstrates that cannabinoids have differing effects in adolescent and adult animals. Whether these findings translate to humans has not yet been investigated. Here we believe we conducted the first study to compare the acute effects of cannabis in human adolescent (n=20; 16-17 years old) and adult (n=20; 24-28 years old) male cannabis users, in a placebo-controlled, double-blind cross-over design. After inhaling vaporized active or placebo cannabis, participants completed tasks assessing spatial working memory, episodic memory and response inhibition, alongside measures of blood pressure and heart rate, psychotomimetic symptoms and subjective drug effects (for example, 'stoned', 'want to have cannabis'). Results showed that on active cannabis, adolescents felt less stoned and reported fewer psychotomimetic symptoms than adults. Further, adults but not adolescents were more anxious and less alert during the active cannabis session (both pre- and post-drug administration). Following cannabis, cognitive impairment (reaction time on spatial working memory and prose recall following a delay) was greater in adults than adolescents. By contrast, cannabis impaired response inhibition accuracy in adolescents but not in adults. Moreover, following drug administration, the adolescents did not show satiety; instead they wanted more cannabis regardless of whether they had taken active or placebo cannabis, while the opposite was seen for adults. These contrasting profiles of adolescent resilience (blunted subjective, memory, physiological and psychotomimetic effects) and vulnerability (lack of satiety, impaired inhibitory processes) show some degree of translation from preclinical findings, and may contribute to escalated cannabis use by human adolescents.
Comparable studies
Other randomized controlled trials on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Cannabidiol inhibits THC-elicited paranoid symptoms and hippocampal-dependent memory impairment Healthy participants | 2012 | Randomized controlled trial | n = 48 |
| Distinct Effects of Δ9-Tetrahydrocannabinol and Cannabidiol on Neural Activation During Emotional Processing Healthy, English-native, right-handed men who had used cannabis 15 times or less in... | 2009 | Double-blind, randomized, placebo-controlled crossover trial | n = 15 |
| Acute Effects of a Single, Oral dose of d9-tetrahydrocannabinol (THC) and Cannabidiol (CBD) Administration in Healthy Volunteers Healthy male subjects | 2012 | Randomized controlled trial | n = 16 |
| Modulation of Mediotemporal and Ventrostriatal Function in Humans by Δ9-Tetrahydrocannabinol Healthy, native English-speaking, right-handed men of white race/ethnicity who had used... | 2009 | Randomized controlled trial | n = 15 |
| Cannabidiol (CBD) content in vaporized cannabis does not prevent tetrahydrocannabinol (THC)-induced impairment of driving and cognition Healthy volunteers with a history of light cannabis use | 2019 | Randomized, double-blind, within-subjects crossover | n = 14 |
Citations in the library
Cited by 34
- The neuropsychopharmacology of cannabis: A review of human imaging studies Pharmacology & Therapeutics October 20, 2018
- 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
- Acute memory and psychotomimetic effects of cannabis and tobacco both ‘joint’ and individually: a placebo-controlled trial Psychological Medicine May 30, 2017
- Dissociable effects of cannabis with and without cannabidiol on the human brain’s resting-state functional connectivity Journal of Psychopharmacology April 23, 2019
- Cannabis Dampens the Effects of Music in Brain Regions Sensitive to Reward and Emotion The International Journal of Neuropsychopharmacology August 30, 2017
and 29 more in the library
Cites 23
- Acute and chronic effects of cannabinoids on effort-related decision-making and reward learning: an evaluation of the cannabis ‘amotivational’ hypotheses Psychopharmacology September 2, 2016
- Human Laboratory Studies on Cannabinoids and Psychosis. Biological Psychiatry April 1, 2016
- Cannabis and tolerance: acute drug impairment as a function of cannabis use history Scientific Reports May 26, 2016
- Acute and Chronic Effects of Cannabinoids on Human Cognition-A Systematic Review. Biological Psychiatry April 1, 2016
- White matter fractional anisotropy over two time points in early onset schizophrenia and adolescent cannabis use disorder: A naturalistic diffusion tensor imaging study. Psychiatry Research April 30, 2015
and 18 more in the library