Acute and chronic effects of cannabinoids on effort-related decision-making and reward learning: an evaluation of the cannabis ‘amotivational’ hypotheses
Will Lawn, Tom P. Freeman, Rebecca Pope, Alyssa Joye, Lisa A. Harvey, Chandni Hindocha, Claire Mokrysz, Abigail Moss, Matthew B. Wall, Michael Bloomfield, Ravi Das, Celia J. A. Morgan, David Nutt, Helen Valerie Curran
Psychopharmacology September 2, 2016 DOI: 10.1007/s00213-016-4383-x (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Peer reviewed |
|---|---|
| Sample size | 17 |
| Population | Participants receiving acute vaporized treatments |
| Interventions | Cann-CBD (8 mg THC) Cann + CBD (8 mg THC + 10 mg CBD) placebo |
| Dose | 8 mg THC, 10 mg CBD, 50 % dose top-up 1.5 h later |
| Topics | Cannabis CBD |
| Keywords | Placebo Cannabinoid |
| Citations | 177 |
| Key findings | THC-only cannabis acutely reduced high-effort choices, while cannabis dependence was linked to impaired reward learning but not motivation. |
Abstract
Rationale: Anecdotally, both acute and chronic cannabis use have been associated with apathy, amotivation, and other reward processing deficits. To date, empirical support for these effects is limited, and no previous studies have assessed both acute effects of Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), as well as associations with cannabis dependence.
Objectives: The objectives of this study were (1) to examine acute effects of cannabis with CBD (Cann + CBD) and without CBD (Cann-CBD) on effort-related decision-making and (2) to examine associations between cannabis dependence, effort-related decision-making and reward learning.
Methods: In study 1, 17 participants each received three acute vaporized treatments, namely Cann-CBD (8 mg THC), Cann + CBD (8 mg THC + 10 mg CBD) and matched placebo, followed by a 50 % dose top-up 1.5 h later, and completed the Effort Expenditure for Rewards Task (EEfRT). In study 2, 20 cannabis-dependent participants were compared with 20 non-dependent, drug-using control participants on the EEfRT and the Probabilistic Reward Task (PRT) in a non-intoxicated state.
Results: Cann-CBD reduced the likelihood of high-effort choices relative to placebo (p = 0.042) and increased sensitivity to expected value compared to both placebo (p = 0.014) and Cann + CBD (p = 0.006). The cannabis-dependent and control groups did not differ on the EEfRT. However, the cannabis-dependent group exhibited a weaker response bias than the control group on the PRT (p = 0.007).
Conclusions: Cannabis acutely induced a transient amotivational state and CBD influenced the effects of THC on expected value. In contrast, cannabis dependence was associated with preserved motivation alongside impaired reward learning, although confounding factors, including depression, cannot be disregarded. This is the first well powered, fully controlled study to objectively demonstrate the acute amotivational effects of THC.
In the evidence
This study is part of the evidence base for a synthesis in the library. Here is how each one recorded it.
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THC-only cannabis reduced high-effort choices relative to placebo, while adding CBD to THC did not produce that reduction; cannabis dependence was linked to weaker reward learning but not to differences in effort-based choice.
Synthesized
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 32
- Are adolescents more vulnerable to the harmful effects of cannabis than adults? A placebo-controlled study in human males Translational Psychiatry November 29, 2016
- 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
- Cannabis and Psychosis Through the Lens of DSM-5 International Journal of Environmental Research and Public Health October 28, 2019
and 27 more in the library
Cites 13
- Cannabidiol inhibits THC-elicited paranoid symptoms and hippocampal-dependent memory impairment Journal of Psychopharmacology October 5, 2012
- Cannabis, motivation, and life satisfaction in an internet sample Substance Abuse Treatment, Prevention, and Policy January 12, 2006
- Oral Cannabidiol does not Alter the Subjective, Reinforcing or Cardiovascular Effects of Smoked Cannabis. Neuropsychopharmacology July 2016
- Acute effects of delta-9-tetrahydrocannabinol, cannabidiol and their combination on facial emotion recognition: a randomised, double-blind, placebo-controlled study in cannabis users. European Neuropsychopharmacology March 2015
- Just say 'know': how do cannabinoid concentrations influence users' estimates of cannabis potency and the amount they roll in joints? Addiction October 2014
and 8 more in the library