Neural substrates of faulty decision-making in abstinent marijuana users.
Karen I Bolla, Dana A Eldreth, John A Matochik, Jean L Cadet
Neuroimage June 2005 DOI: 10.1016/j.neuroimage.2005.02.012 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational case-control study Peer reviewed |
|---|---|
| Sample size | 22 |
| Population | 11 heavy marijuana users abstinent for 25 days and 11 non-drug users |
| Duration | 25-day abstinence before testing |
| Measures | Iowa Gambling Task (IGT), PET H(2)(15)O |
| Topics | Cannabis |
| Key findings | The authors report a dose-related association between heavier marijuana use and lower Iowa Gambling Task performance plus altered brain activity, with heavy users (53-84 joints/week) showing less left medial orbitofrontal and greater left cerebellar activation than moderate users (8-35 joints/week). Moderate users performed and activated similarly to controls, suggesting a "threshold effect." They propose that heavy users may focus on immediate reinforcement while ignoring negative consequences, possibly increasing vulnerability to addiction. |
Abstract
Persistent dose-related cognitive decrements have been reported in 28-day abstinent heavy marijuana (MJ) users. However, the neural substrates of these decrements in cognitive performance are not known. This study aimed to determine if 25-day abstinent MJ users show persistent dose-related alterations in performance and brain activity using PET H(2)(15)O during the Iowa Gambling Task-IGT (a decision-making task). Eleven heavy MJ users and 11 non-drug users participated. The MJ group resided in an inpatient research unit at the NIH/NIDA-IRP for 25 days prior to testing to ensure abstinence. A dose-related association was found between increased MJ use and lower IGT performance and alterations in brain activity. The MJ group showed greater activation in the left cerebellum and less activation in the right lateral orbitofrontal cortex (OFC) and the right dorsolateral prefrontal cortex (DLPFC) than the Control group. When the MJ group was divided into Moderate (8-35 joints/week) and Heavy users (53-84 joints/week), the Heavy MJ group showed less activation in the left medial OFC and greater activation in the left cerebellum than the Moderate group. However, brain activity and task performance were similar between the Moderate MJ users and the Control group, suggesting a "threshold effect". These preliminary findings indicate that very heavy users of MJ have persistent decision-making deficits and alterations in brain activity. Specifically, the Heavy MJ users may focus on only the immediate reinforcing aspects of a situation (i.e., getting high) while ignoring the negative consequences. Thus, faulty decision-making could make an individual more prone to addictive behavior and more resistant to treatment. Finally, it is unclear if these neurologic findings will become progressively worse with continued heavy MJ use or if they will resolve with abstinence from MJ use.
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
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- The neuropsychopharmacology of cannabis: A review of human imaging studies Pharmacology & Therapeutics October 20, 2018
- Neuroimaging in cannabis use: a systematic review of the literature Psychological Medicine July 23, 2009
- Effects of Cannabis on Impulsivity: A Systematic Review of Neuroimaging Findings Current Pharmaceutical Design May 10, 2014
- Differences in Inhibitory Control and Resting Brain Metabolism between Older Chronic Users of Tetrahydrocannabinol (THC) or Cannabidiol (CBD)—A Pilot Study Brain Sciences June 23, 2022
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Cites 6
- Altered brain tissue composition in heavy marijuana users. Drug and Alcohol Dependence January 7, 2005
- Abnormal brain activity in prefrontal brain regions in abstinent marijuana users. Neuroimage November 2004
- Marijuana alters the human cerebellar clock. Neuroreport June 11, 2003
- Effects of smoking marijuana on brain perfusion and cognition. Neuropsychopharmacology June 2002
- Effects of frequent marijuana use on memory-related regional cerebral blood flow. Pharmacology, Biochemistry, and Behavior May 2002
and 1 more in the library