Altered affective response in marijuana smokers: an FMRI study.
Staci A Gruber, Jadwiga Rogowska, Deborah A Yurgelun-Todd
Drug and Alcohol Dependence November 1, 2009 DOI: 10.1016/j.drugalcdep.2009.06.019 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Case-control fMRI study Peer reviewed |
|---|---|
| Sample size | 30 |
| Population | 15 chronic heavy marijuana smokers and 15 non-marijuana-smoking control subjects |
| Topics | Cannabis |
| Key findings | Chronic heavy marijuana smokers showed relatively decreased anterior cingulate and amygdalar activity while viewing masked happy and fearful faces, whereas controls showed relative increases in these regions. The authors suggest this indicates that chronic smokers process emotional information differently, even below the level of conscious processing. |
Abstract
More than 94 million Americans have tried marijuana, and it remains the most widely used illicit drug in the nation. Investigations of the cognitive effects of marijuana report alterations in brain function during tasks requiring executive control, including inhibition and decision-making. Endogenous cannabinoids regulate a variety of emotional responses, including anxiety, mood control, and aggression; nevertheless, little is known about smokers' responses to affective stimuli. The anterior cingulate and amygdala play key roles in the inhibition of impulsive behavior and affective regulation, and studies using PET and fMRI have demonstrated changes within these regions in marijuana smokers. Given alterations in mood and perception often observed in smokers, we hypothesized altered fMRI patterns of response in 15 chronic heavy marijuana smokers relative to 15 non-marijuana smoking control subjects during the viewing of masked happy and fearful faces. Despite no between-group differences on clinical or demographic measures, smokers demonstrated a relative decrease in both anterior cingulate and amygdalar activity during masked affective stimuli compared to controls, who showed relative increases in activation within these regions during the viewing of masked faces. Findings indicate that chronic heavy marijuana smokers demonstrate altered activation of frontal and limbic systems while viewing masked faces, consistent with autoradiographic studies reporting high CB-1 receptor density in these regions. These data suggest differences in affective processing in chronic smokers, even when stimuli are presented below the level of conscious processing, and underscore the likelihood that marijuana smokers process emotional information differently from those who do not smoke, which may result in negative consequences.
Comparable studies
Other experimental studies on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Smoked Cannabis' Psychomotor and Neurocognitive Effects in Occasional and Frequent Smokers Occasional (<2x/week) and frequent (≥4x/week) cannabis smokers | 2015 | Controlled within-subjects study | n = 25 |
| Dissociable effects of cannabis with and without cannabidiol on the human brain’s resting-state functional connectivity Healthy volunteers experienced with cannabis but not regular users | 2019 | Within-subjects experimental design | n = 17 |
| Which biological and self-report measures of cannabis use predict cannabis dependency and acute psychotic-like effects? Young cannabis users | 2018 | Observational study (naturalistic, within-subject counterbalanced design) | n = 410 |
| Cannabis Essential Oil: A Preliminary Study for the Evaluation of the Brain Effects Healthy volunteers | 2018 | Experimental study | n = 5 |
| Coming off cannabis: a cognitive and magnetic resonance imaging study in patients with multiple sclerosis Patients with multiple sclerosis who began using cannabis after disease onset, used it... | 2019 | Quasi-experimental study with odd-even allocation | n = 40 |
Citations in the library
Cited by 24
- The neuropsychopharmacology of cannabis: A review of human imaging studies Pharmacology & Therapeutics October 20, 2018
- Attenuated frontal and sensory inputs to the basal ganglia in cannabis users Addiction Biology March 3, 2016
- Effects of delta-9-tetrahydrocannabinol on evaluation of emotional images Journal of Psychopharmacology May 13, 2012
- Cannabinoid Modulation of Amygdala Subregion Functional Connectivity to Social Signals of Threat The International Journal of Neuropsychopharmacology December 28, 2014
- Cannabis-induced oceanic boundlessness Journal of Psychopharmacology March 28, 2021
and 19 more in the library
Cites 12
- Antidepressant-like activity and modulation of brain monoaminergic transmission by blockade of anandamide hydrolysis Proceedings of the National Academy of Sciences December 13, 2005
- Cannabinoid Modulation of Amygdala Reactivity to Social Signals of Threat in Humans Journal of Neuroscience March 5, 2008
- A role for cannabinoid CB1 receptors in mood and anxiety disorders. Behavioural Pharmacology September 2005
- Neuroimaging of marijuana smokers during inhibitory processing: a pilot investigation. Brain research. Cognitive brain research April 2005
- Abnormal brain activity in prefrontal brain regions in abstinent marijuana users. Neuroimage November 2004
and 7 more in the library