Regular cannabis users showed impaired ability to regulate negative emotions in brain scans | Research

The takeaway

An fMRI study found that regular marijuana users had weaker ability to downregulate negative emotions, with disrupted communication between the amygdala and prefrontal cortex during emotional regulation tasks.

Read this if you use cannabis regularly and have noticed difficulty managing stress or negative emotions.

Disrupted amygdala-prefrontal connectivity during emotion regulation in cannabis users

What the researchers found

Researchers compared 23 regular marijuana users to 20 non-using controls using brain imaging during an emotion regulation task. Participants viewed negative images and were asked to use cognitive reappraisal, essentially reframing the meaning of what they saw to reduce its emotional impact.

Cannabis users showed significantly worse emotion regulation success on the behavioral level. Their brain scans revealed increased activity in frontal motor regions during reappraisal attempts, which the researchers interpreted as an unsuccessful attempt to recruit additional neural resources to compensate for impaired regulation.

Critically, cannabis users showed impaired ability to dampen amygdala activity during emotion regulation. This was accompanied by decreased functional connectivity between the amygdala and the dorsolateral prefrontal cortex, a connection considered essential for top-down emotional control. The amygdala essentially was not receiving the regulatory signals from higher brain regions as effectively.

Why it matters

Difficulty regulating negative emotions is a known risk factor for mental health problems and substance use disorders. If regular cannabis use impairs the brain circuits responsible for emotion regulation, this could create a feedback loop where cannabis is used to cope with negative emotions but simultaneously weakens the brain's own capacity to manage them.

The numbers in context

23 regular marijuana users and 20 non-using controls. Cannabis users showed significantly worse behavioral emotion regulation (p < 0.05). Increased frontal network activity in users during reappraisal (p < 0.05, FWE corrected). Impaired amygdala downregulation with decreased amygdala-DLPFC connectivity (p < 0.05, FWE corrected).

How the study worked

This was a cross-sectional fMRI study comparing 23 regular marijuana users to 20 demographically matched non-using controls. Participants completed a cognitive emotion regulation (reappraisal) paradigm during brain scanning. Both behavioral performance and neural activity patterns were measured and compared between groups.

What this study cannot tell us

The cross-sectional design cannot determine whether cannabis caused the emotion regulation deficits or whether people with pre-existing deficits were more likely to use cannabis. The sample was small. The study did not assess specific cannabis use parameters like potency, strain, or frequency in detail. Only one type of emotion regulation strategy (reappraisal) was tested.

How to read the evidence

This is a small cross-sectional neuroimaging study that identifies neural correlates but cannot establish causation.

When this study was published

Published in 2017. Neuroimaging research on cannabis and emotion has continued to develop since.

The bigger picture

This study connects cannabis use to a fundamental psychological process that underlies mental resilience. Emotion regulation deficits have been linked to depression, anxiety, PTSD, and continued substance use. Understanding how cannabis affects these neural circuits helps explain the complex relationship between cannabis use and mental health outcomes.

Questions still open

Do emotion regulation deficits reverse after cannabis cessation? Are certain individuals more susceptible to these neural changes based on genetics or baseline brain function? Does the age of onset of cannabis use affect the severity of emotion regulation impairment?

Common questions

Does cannabis help or hurt with managing emotions?

This study suggests that while people may use cannabis to feel better in the moment, regular use is associated with weaker brain circuits for emotion regulation. The amygdala-prefrontal connection that allows for top-down emotional control appeared disrupted in regular users.

Is this damage permanent?

The study could not answer this because it only measured users at one point in time. Whether these neural changes reverse with abstinence would require longitudinal research following users who stop consuming.

Read the original research

Emotion regulation deficits in regular marijuana users.

Human brain mapping, 38(8), 4270-4279

View on PubMed ↗Publisher’s paper ↗

Citation

Zimmermann, Kaeli; Walz, Christina; Derckx, Raissa T; Kendrick, Keith M; Weber, Bernd; Dore, Bruce; Ochsner, Kevin N; Hurlemann, René; Becker, Benjamin. (2017). Emotion regulation deficits in regular marijuana users.. Human brain mapping, 38(8), 4270-4279. https://doi.org/10.1002/hbm.23671