New research from King’s College London and the University of Bath has uncovered key links between cannabis use, paranoia, and childhood trauma.
The findings, based on data from the Cannabis & Me survey—the largest of its kind—highlight the psychological risks associated with cannabis use, particularly for individuals who begin using it to self-medicate.
Published in BMJ Mental Health, this study analyzed responses from 3,389 adult cannabis users.
It explored their reasons for starting cannabis, weekly THC consumption, and mental health outcomes.
Key findings include:
Those who began using cannabis to manage physical or mental health conditions (e.g., pain, anxiety, depression, or minor psychotic symptoms) had significantly higher paranoia, anxiety, and depression scores.
Those who started out of curiosity or social reasons had the lowest scores in these areas.
Average weekly THC consumption was around 206 units. Users who started for mental health reasons or due to household exposure consumed more THC (248–287 units).
Researchers suggest using standard THC units like alcohol units to help individuals monitor their intake.
Published in Psychological Medicine, this study explored how childhood trauma affects paranoia and cannabis consumption.
Key findings include:
52% of respondents reported childhood trauma, with emotional and physical abuse being the strongest predictors of paranoia.
Trauma types like emotional abuse and household discord were linked to both higher THC use and paranoia. Other trauma types (e.g., bullying, neglect) did not show the same effect.
Cannabis use was found to worsen the link between childhood trauma and paranoia.
These findings underline the need for: Early screening for trauma in individuals with paranoia. Public education on the risks of self-medicating with cannabis. Better support systems and awareness around the mental health impacts of cannabis use, especially as legalization debates continue globally.
The Cannabis & Me project was supported by the Medical Research Council (MRC). Key contributors include Dr. Edoardo Spinazzola, Dr. Giulia Trotta, Professor Tom Freeman, Professor Marta Di Forti, and others at King’s IoPPN and the University of Bath.
If you care about mental health, please read studies about Middle-aged women with no kids may have this mental issue and findings of scientists find a cause of mental illnesses induced by childhood abuse.
For more about mental health, please read studies about Frequent painkiller use linked to mental health risks in these people and findings of Common depression drugs may offer new treatment for bipolar disorder.
The study is published in BMJ Mental Health.
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