Summary: Young individuals who use high-potency cannabis between ages 16 and 18 are twice as likely to experience psychosis by their mid-twenties compared to those who use lower-potency strains.
This research utilized data from the Children of the 90s study, tracking thousands of participants from Bristol. It is the first longitudinal study to correlate early cannabis use with specific potency levels to later psychotic experiences.
The findings underscore the significant mental health risks associated with stronger forms of cannabis, highlighting an urgent need for public health education and policy adjustments.
Key Facts:
- Participants who used high-potency cannabis reported a doubled rate of psychotic experiences compared to those using less potent forms.
- The study indicates that 10.1% of high-potency cannabis users developed new psychotic symptoms post-use, significantly higher than the 3.8% using lower-potency variants.
- This research contributes to a broader discourse on cannabis potency, with THC levels having risen dramatically over several decades, potentially exacerbating mental health issues among young users.
Source: University of Bath
Young individuals consuming higher-potency cannabis, such as skunk, between ages 16 and 18, are twice as likely to have psychotic experiences from age 19 to 24 compared to those using lower-potency cannabis.
That’s according to a new University of Bath study published today in the scientific journal, Addiction.
Previous studies from the Addiction and Mental Health Group at the University of Bath have found that the concentration of THC in cannabis – the main psychoactive component of cannabis – has increased by 14% from 1970 to 2017, meaning today the UK cannabis market is dominated by high-potency cannabis varieties like skunk.
This new study is the first longitudinal examination of early adolescent psychosis measures and detailed cannabis potency.
This data stems from the Children of the 90s study, the most comprehensive research project of its kind. It commenced in Bristol over 30 years ago, gathering information and data from thousands of families across the city.
Nearly 14,000 individuals were recruited into the study from birth, many of which continue to take part in the study to the present day. At ages 16 to 18, participants were asked about recent cannabis use. By age 24, they disclosed their primary cannabis type and any experiences of psychotic experiences such as hallucinations or delusions.
Lead author, Dr Lindsey Hines from the University of Bath Department of Psychology said: “Young people using higher-potency forms of cannabis are twice as likely to have experiences associated with psychosis, such as hallucinations and delusions.
“Importantly, the young people we asked had not previously reported these experiences before starting their cannabis use. This adds to the evidence that use of higher-potency cannabis may negatively impact mental health.”
This study adds to a wealth of research stemming from the ALSPAC study, which examines various topics from links between medication taken while pregnant and a child’s well-being, to the way social media can lead to self-harm.
Key Findings from this study:
• 6.4% of young people using cannabis had new psychotic experiences, compared to 3.8% of non-users
• After starting to use cannabis, 10.1% of young people using higher-potency cannabis reported new psychotic experiences, compared to 3.8% using lower-potency.
• Those using higher-potency cannabis were more than twice as likely to report new psychotic experiences after starting to use cannabis, compared to those using lower-potency cannabis.
This research adds to the growing body of evidence indicating that high-potency cannabis use is associated with an increased likelihood, and now incidence, of psychotic experiences.
The researchers are now calling for better evidence on the long-term outcomes of use of higher-potency cannabis, and exploration of measures to reduce the potency of cannabis available to young people.
Dr Hines said: ”Cannabis is changing and higher-potency cannabis is increasingly available. These findings show the how important it is to understand the long-term effects of higher-potency use in young people. We need to improve messaging and information available to young people on the impacts of cannabis use in the 21st century.”
Funding: The study is published in the scientific journal, Addiction and was funded by The Wellcome Trust.
About this psychosis and THC research news
Author: Chris Melvin
Source: University of Bath
Contact: Chris Melvin – University of Bath
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Incident psychotic experiences following self-reported use of high-potency cannabis: Results from a longitudinal cohort study” by Lindsey Hines et al. Addiction
Abstract
Incident psychotic experiences following self-reported use of high-potency cannabis: Results from a longitudinal cohort study
Background and aims
High-potency cannabis has been associated with increased risk of psychosis, but a lack of prospective data hinders understanding of causality in this relationship. This study aimed to combine prospective report of cannabis use with retrospective report of potency to infer the potency of cannabis used in adolescence and explore whether use of cannabis, and the use of high-potency cannabis, in adolescence is associated with incident psychotic experiences.
Design
Population-based birth cohort study.
Setting
United Kingdom.
Participants
n = 5570 participants who reported on any cannabis use (yes/no) age 16 and 18 years, and n = 1560 participants from this group who also retrospectively reported on cannabis potency.
Measurements
In questionnaires at ages 16 and 18, individuals self-reported lifetime cannabis use, and at age 24, participants reported the type of cannabis they most commonly used in the whole time since first using cannabis. Psychotic experiences were assessed at age 24 years using the semi-structured Psychosis-Like Symptom Interview, with incident defined as new-onset occurring between ages 19 and 24 years.
Findings
Use of high-potency cannabis at age 16 or 18 was associated with twice the likelihood of experiencing incident psychotic experiences from age 19–24 (Odds Ratio 2.15, 95% Confidence Intervals 1.13–4.06). There was less evidence for an effect of any cannabis use on incident psychotic experiences (Odds Ratio 1.45, 95% Confidence Intervals 0.94–2.12).
Conclusions
Use of high-potency cannabis appears to be associated with increased likelihood of psychotic experiences.
