Get a Clue - Weed

Details: Published: 14 October 2026; Hits: 4

People who use cannabis are about one and a half times as likely to become victims of violence, and the association is stronger among women than men.

That finding sits inside a review of 63 studies and more than 265,000 people, led by the Institute of Psychiatry, Psychology and Neuroscience at King’s College London and published in Psychological Medicine. Most of the coverage has led on the other half of the result, that cannabis users were roughly twice as likely to commit a violent act. The victimisation figure has been reported as a footnote, and it deserves better.

What being a victim means in this review
The researchers used the World Health Organization’s definition of violence, which covers physical, sexual and psychological violence against another person, inside intimate relationships as well as outside them. Where a study measured several kinds, the most serious one was counted.

So the victimisation finding is not confined to street assaults. It takes in violence inside the home and inside relationships, and it covers sexual and psychological harm alongside physical injury.

That matters for how the number is read. A person who uses cannabis is, on this evidence, more likely to be on the receiving end of all of it.

Why the gender difference deserves attention
The association was stronger in women. The review does not explain why, and the authors are careful not to claim a mechanism.

What can be said is that the usual public conversation about cannabis is built around a different person entirely: a young man, making a choice about his own body, whose risks are his own to carry. The victimisation finding does not fit that frame. It describes harm arriving from outside, and arriving more often for women.

Prevention work aimed at women and girls rarely covers cannabis at all. On this evidence it should.

The limits, stated plainly
The review identifies an association and does not prove that cannabis causes violence in either direction. The authors say so directly.

Cannabis use sits alongside other things that raise the risk of being harmed, including alcohol, other drugs and difficult social circumstances. Untangling those was beyond what the pooled studies allowed.

Only a small number of the included studies recorded how much or how often people used, so dose could not be tested. And most of the research was carried out before high potency products became common. The authors suggest that daily use of what is sold today could carry stronger effects, which means the figures in this review may understate the current picture rather than overstate it.

What the authors asked for
Two practical recommendations came out of the review. Mental health services should ask about cannabis use as a routine part of assessing violence risk. And public health information about cannabis should include the connection with violence.

Marta Di Forti, a co-author at King’s College London and the South London and Maudsley NHS Foundation Trust, put the clinical experience behind it:

” As a clinician, I’ve seen how heavy cannabis use can be a factor in violence. We’ve been cautious for a long time about how far we could go in describing this link, but a review of this size lets us speak with more confidence about the risks, while being careful not to stigmatise people who use cannabis more broadly.”

Senior author Sir Robin Murray made the wider point:

“As cannabis becomes more commercialised and legalised around the world, the conversation about its risks has focused mostly on the person using it. This review shows that violence, both committing it and experiencing it, needs to be part of that conversation too.”

The harm that never makes the label
Every argument for commercialising cannabis rests on a single idea: that the user is an adult making an informed choice about their own life. Harms to other people are treated as someone else’s problem, or as evidence of bad policing rather than bad product.

This review puts two findings in front of that argument. Users are more likely to harm others, and they are more likely to be harmed themselves. Neither appears on any packet, in any dispensary leaflet, or in the campaign material that sells legalisation as a matter of personal freedom.
Prevention starts from the opposite assumption, that a drug’s effects do not stop at the person using it. The question for anyone promoting cannabis as benign is which of these two numbers they intend to tell people about.

(Source: WRD News)

Details: Published: 14 October 2026; Hits: 5

Adults with hard to treat epilepsy who used cannabis almost every day had more than twice as many convulsive seizures a year as those who did not use it, and they reached the point of needing specialist inpatient monitoring thirteen years earlier.

The finding comes from a study published in Epilepsia on 28 September 2026, led by researchers at Washington University in St Louis using patient records from the University of Wisconsin School of Medicine and Public Health. It arrives while cannabis is still widely sold on the promise that it helps with sleep, anxiety and, in some marketing, seizures themselves.

What the researchers looked at
The team reviewed the records of 64 adults with drug resistant focal epilepsy who were admitted to an epilepsy monitoring unit between 2019 and 2024. Drug resistant means seizures that two or more antiseizure medicines have failed to control. In the unit, doctors watch seizures as they happen so they can adjust medication or assess whether surgery is an option.

Twenty two of the 64 had documented cannabis use on 20 or more days a month. Their average age was 31 and roughly a quarter were women. The 42 with no documented use averaged 40 years old and just over half were women.

The gap between the groups was wide. Convulsive seizures, the kind that spread across both sides of the brain, affected 91 per cent of the frequent users against 57 per cent of the nonusers. Frequent users had more than twice as many of those seizures a year. They were also on more antiseizure medicines and were more likely to have temporal lobe epilepsy.

Five years against eighteen
The clearest number in the study is how long it took each group to end up in specialist care. Frequent cannabis users were admitted to the monitoring unit an average of five years after their first seizure. For nonusers the average was 18.1 years. The difference was statistically significant.

That gap matters because admission to a monitoring unit usually marks the point at which standard treatment has stopped working. Reaching it in five years rather than eighteen suggests the condition hardened against medication far faster in the group using cannabis most days.
“We did not anticipate how striking the results would be,” senior author Aaron Struck told Healio.

Which came first
The obvious objection is that people with worse epilepsy might turn to cannabis for relief, which would explain the association without cannabis doing any harm. The records point the other way. Among the frequent users whose timelines were documented, cannabis use began before the seizures did.

The profile of that group was also unusual. They were mostly men in their twenties with none of the risk factors that normally sit behind severe epilepsy, such as the structural brain damage that typically shows up in patients whose seizures have resisted treatment for years.

Struck has said he started asking the question after seeing patients with severe seizures and no apparent reason for them.

Cannabis is not cannabidiol
Much of the public confusion here comes from treating one plant as one medicine. A purified cannabidiol extract has been approved for use alongside other medicines in a small number of rare epilepsy syndromes, including Dravet and Lennox-Gastaut, after randomised trials in children and adolescents. That approval covers a regulated, measured, single compound.

The cannabis people buy is a different product. Its main psychoactive ingredient is tetrahydrocannabinol, which can alter how readily neurons fire and may make seizures more likely rather than less. The same research group has published two case reports of men with focal epilepsy whose cannabis use coincided with breakthrough seizures and poor control, including a suggestion that it blunted the effect of implanted neurostimulation.

A regulatory approval for one compound in one group of patients is routinely stretched into a general claim that cannabis treats epilepsy. The new data give patients a reason to doubt that claim.

What the authors will and will not say
The researchers are careful about what 64 records can prove. The study is retrospective, the sample is small, and cannabis use was taken from what patients reported and what clinicians wrote down. An association is not causation, and the team says so plainly. A follow up study is planned to work out how much use matters and whether stopping helps.

First author Santiago Philibert-Rosas said the honest answer to a patient asking whether cannabis is affecting their seizures is that doctors do not yet know.

Struck drew a practical conclusion anyway. If a patient is using cannabis for anxiety or sleep, he said, “I’d prefer to treat those problems with drugs we understand” rather than something largely unregulated whose effect on the brain is unclear.

The question nobody is asking patients
The practical lesson is small and immediate. Cannabis use is rarely covered in a busy neurology appointment, and patients who use it for sleep or anxiety often do not think to mention it. Asking the question costs nothing and may change what a clinician recommends.

The wider lesson is harder. Daily and near daily cannabis use in the United States now outnumbers comparable daily drinking, and the products on sale have been normalised faster than anyone has measured what they do. This study looked at one condition, in one monitoring unit, over five years, and found a group of young men whose epilepsy ran out of treatment options in a third of the usual time.

That is the pattern worth watching. Where cannabis has been sold as low risk and quietly medicinal, the research keeps arriving afterwards, and it keeps pointing in the same direction.

(Source: WRD News)

Details: Published: 13 October 2026; Hits: 44

Marijuana industry funding is not the small, local story its supporters like to tell. A new tracker called Who Funds Marijuana Legalization? logs 62 entries showing that tobacco, alcohol and drug companies have put billions of dollars into the sector since 2018. The biggest marijuana operators, meanwhile, have spent heavily on ballot measures, lobbyists and political access in Washington.

The industry often calls itself a mom and pop movement. The records paint a different picture. Thetracker, last updated in September 2026, draws on company filings, campaign finance records and linked reporting. Its entries split into 9 tobacco, 12 alcohol, 8 pharma, 16 marijuana industry and 17 political cases.

Big Tobacco Buys Into Marijuana
Altria, maker of Marlboro, paid $1.8 billion in December 2018 for 45% of Canadian producer Cronos Group. It also took four of seven board seats and signed a global marijuana exclusivity deal. That investment is now worth $319 million.

British American Tobacco has been just as active. It has funded Canadian producer Organigram in three rounds, starting with C$221 million for 19.9% in 2021. Imperial Brands, for its part, bought a C$123 million convertible note in Auxly and took a board seat.

Marijuana industry funding from tobacco firms also extends to lobbying. Altria helped found a coalition called CPEAR with Molson Coors, Constellation Brands and the convenience store lobby. Its aim is a federal marijuana framework. The tracker’s warning is blunt: preventing another Big Tobacco starts with knowing who writes the cheques.

Alcohol and Pharma Place Their Own Bets
Constellation Brands, maker of Corona and Modelo, spent C$5 billion (US$4 billion) for about 37% of Canopy Growth. The tracker calls it the largest investment in the industry’s history. Most of it has since been written off.

Alcohol companies have now turned to hemp THC drinks. The Wine and Spirits Wholesalers of America launched a campaign to sell them through the alcohol system and cites $28.4 billion in potential market activity. NielsenIQ puts retail sales of THC drinks near $250 million, with about $150 million of that in liquor stores.

Pharma has its own stake. Jazz Pharmaceuticals paid $7.2 billion for GW Pharmaceuticals, maker of Epidiolex. Its lobbyists then worked on hemp and CBD rules covering products that compete with its prescription CBD. Insys Therapeutics went further. It gave $500,000 to defeat Arizona’s 2016 legalisation measure while telling the SEC that legal marijuana would compete with its synthetic THC drug.

Political Cash Follows the Same Path
Marijuana industry funding in politics comes largely from the five biggest operators, who supply nearly all the money behind marijuana legalisation. Trulieve provided $144.6 million of the $153.8 million (94%) behind Florida’s 2024 Amendment 3. It then added at least $32.4 million to a 2026 rerun, bringing its Florida total to about $177 million.

In June 2026, six marijuana companies gave $11.5 million in a single month to a super PAC linked to Trump. According to FEC filings cited by the tracker, marijuana money to Trump linked super PACs has passed $15 million since 2025.

Lobbying tells a similar story. OpenSecrets figures show marijuana clients reported $5.2 million in federal lobbying in 2024. More than half of the industry’s registered lobbyists that year had worked in government before.

The Revolving Door Keeps Turning
Marijuana industry funding has a people side too, and former officials appear throughout the list. Former House Speaker John Boehner joined the board of Acreage Holdings in April 2018. The New York Times reported that his shares carried the prospect of a payday as high as $20 million. Boehner and former HHS Secretary Kathleen Sebelius later became honorary chairs together of the National Cannabis Roundtable.
Other names include former Senate Majority Leader Tom Daschle, former Senator Cory Gardner and former Deputy Attorney General James Cole. Altogether, the tracker lists 17 politicians and regulators who took paid or advisory roles.

Why Marijuana Industry Funding Matters
Not every bet paid off, and the tracker says so. Several big investments were written down or sold. Even so, the spending shapes the rules, the ballot questions and the public debate.

Communities weighing legalisation deserve to know who is paying for the message. The money behind marijuana legalisation comes from companies with decades of experience selling products that harm health. Before the next ballot measure or federal ruling, voters should ask a simple question. Who paid for it?

(Source: WRD News)

Details: Published: 12 October 2026; Hits: 36

Cannabis and tobacco use often go hand in hand. For young people who already show early signs of psychosis, that habit may carry more weight than anyone assumed. Two linked studies from the same North American cohort point to a higher chance of developing a psychotic disorder, and weaker results on thinking tasks, among those who use both.

Daniel Bello and colleagues at Vanderbilt University Medical Center posted the first study on medRxiv in September 2025. Peer review hasn’t happened yet.

A second paper, in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging in August 2026, checks whether the pattern also shows up in memory, attention and learning.

Why Cannabis and Tobacco Use Matters for Young People at Risk
Psychosis and substance use overlap heavily, and the numbers show it. Up to 60 per cent of people with schizophrenia use tobacco, three times the general population rate. Cannabis use disorder affects 43 per cent of people with schizophrenia, against 15 per cent in the wider population. Tobacco is the leading preventable cause of early death in schizophrenia, and life expectancy runs about 20 years shorter.

The habits are converging, too. Among 18 to 25 year olds in the United States, one in five daily cigarette smokers also uses cannabis every day. Daily cannabis use among cigarette smokers rose from 4.9 per cent in 2002 to 9 per cent in 2014, according to the authors.

Still, few studies had asked what cannabis and tobacco use together means for people at clinical high risk of psychosis. That is the stage before illness fully arrives, when faint symptoms, low mood and social strain begin to show. Timing matters here. Substance use usually starts in adolescence, before psychosis does, and roughly 77 per cent of people report trying tobacco before their first psychotic symptoms.

Who Took Part in the Research
Both papers use NAPLS2, the North American Prodrome Longitudinal Study 2, which tracked young people across eight sites. The preprint analysed 1,014 people: 734 at clinical high risk and 280 healthy controls. Everyone reported their substance use over the past 30 days, and researchers then followed them for two years. In that time, 83 of the 734 at risk participants developed a psychotic disorder.

The team split the at risk group by use. Some used cannabis only, some tobacco only, some both, some other substances such as alcohol, and some nothing at all. In the cognition paper, 97 people used both, 78 used tobacco only and 79 used cannabis only. Average ages across groups ranged from about 17 to 21.

Combined Use of Cannabis and Tobacco and the Psychosis Hazard
The headline finding concerns risk. People who used both substances had a hazard ratio of 2.53 for developing psychosis, compared with people who used neither. Put simply, their risk more than doubled over follow up. The 95 per cent confidence interval ran from 1.44 to 4.45.
Heavy use lifted the number further. At that level, cannabis and tobacco use together produced a hazard ratio of 3.63, a more than threefold increase. By contrast, cannabis alone (1.54) and tobacco alone (1.69) did not reach statistical significance as separate groups.

Why might that be? The authors give two possible explanations. Using both could amplify what either does to the brain’s dopamine systems. Or the pairing may simply mark someone whose risk was already higher. The data can’t tell these apart.

Cannabis Appears to Carry the Heavier Weight
Cannabis held up when the team adjusted for tobacco. More frequent use carried a hazard ratio of 1.22. Tobacco’s link dropped to 1.15 and lost significance once cannabis entered the model. The authors call cannabis the primary culprit, although they point to earlier meta analyses that treat it as a contributor in predisposed people, not a sole cause.

Symptoms painted a muddier picture. Across the full sample, more frequent use of either substance went with worse psychosis, anxiety and depression scores. Within the at risk groups, though, baseline severity looked much the same. Neither substance showed any sign of easing symptoms.

What the Second Study Found About Thinking Skills
The Biological Psychiatry paper covered 1,012 people: 734 at risk and 278 healthy controls. Dr Heather Burrell Ward of Vanderbilt University Medical Center is the corresponding author. In this study, participants completed the MATRICS Consensus Cognitive Battery and an auditory continuous performance task.

Young people who used both substances scored below healthy controls on global cognition, working memory, verbal learning and attention. On the auditory task, the combined use group also showed weaker vigilance than either single substance group. The authors suggest those vigilance and working memory gaps might help explain the link to psychosis.

Reading the Cognitive Findings With Care
Not everything fits a simple story. Cannabis and tobacco use did not behave the same way on every measure. The cannabis only group matched healthy controls on global cognition. Their estimated IQ topped that of the combined use and tobacco groups, and heavier cannabis use went with better working memory. The authors suspect these young people may simply start out with stronger cognitive function.

Another oddity: at risk participants who used nothing scored lower on several measures and had the weakest social functioning of any at risk group. One explanation from the authors is that sociable young people meet substances more often, while those with severe negative symptoms step back from those settings.

None of this makes substance use protective. The study looked at one point in time, relied on self reported use over 30 days and couldn’t measure cannabis potency. Data came from 2009 to 2013, so potency has climbed since. Cause and direction remain open. As for nicotine, the authors doubt it worsens thinking. People with underlying cognitive difficulties may be drawn to it instead.

What This Means for Early Intervention
Clinicians should ask about both substances as a matter of routine, the authors say, because the pairing may flag a more severe cognitive risk profile than either alone. They add that reducing use in this group is warranted, since cutting back might delay or prevent psychosis for some people.

For families, schools and health services, the takeaway is simple. A conversation about cannabis and tobacco use costs little and can start early. However, asking about cannabis alone could miss half the picture. The researchers also want larger, longer studies that track people over time, measure use in finer detail and include newer high potency products and vaping.

Until that evidence arrives, the message holds. For young people already at risk of psychosis, cannabis and tobacco use deserves attention sooner rather than later.

Dalgarno Institute

Sources:
Cannabis and Tobacco Co-Use Predicts Psychosis in Clinical High Risk Cohorts
Cannabis and Tobacco Co-Use Is Associated With Impaired Neurocognitive Performance in Individuals at Clinical High Risk for Psychosis

Details: Published: 12 October 2026; Hits: 9

A new systematic review and meta-analysis in Psychological Medicine puts hard numbers on the cannabis violence risk. The authors pooled 63 peer reviewed studies covering 265,079 people. Cannabis users had significantly higher odds of committing violent acts. Giulia Trotta and colleagues from King’s College London and the South London and Maudsley NHS Foundation Trust searched the literature up to November 2024. Anyone debating cannabis policy should read their conclusion.

The timing matters. Professor Bobby Smyth, writing about the paper on LinkedIn, notes a recent flurry of reports and opinion pieces. They urge societies to dismantle drug laws in the name of women’s wellbeing. He calls this the latest gambit of a billionaire funded legalisation lobby. Whatever one makes of that framing, the new evidence on violence linked to cannabis use lands in the middle of the argument.

Inside the Cannabis Violence Risk Evidence
The headline numbers agree with each other. In the general population, cannabis users had odds of perpetrating violence of 2.05 (95 per cent confidence interval 1.74 to 2.41). Among psychiatric patients the figure was 2.49 (1.72 to 3.61). In plain terms, cannabis users had roughly twice the odds of committing violence as non-users in the same populations.

Cannabis use was also tied to a higher chance of becoming a victim of violence, with an odds ratio of 1.49 (1.38 to 1.60). That risk was higher for women (1.60) than for men (1.30). Across the populations studied, the picture is consistent.

Earlier reporting, including a July 2024 WRD News article, cited a meta-analysis of 30 studies and nearly 300,000 participants. It also found roughly twice the odds of violent behaviour among users. The new review draws on more than twice as many studies. It examines perpetrators and victims, yet it points the same way.

Convictions and Clinical Settings Tell the Starkest Story
Violence that led to a criminal conviction showed the largest effects. The odds ratio was 3.75 (2.54 to 5.53) in the general population and 4.21 (2.86 to 6.22) among psychiatric patients. Each figure rests on three studies. The authors call this finding particularly important. They point to the severity of the violence and the likely greater reliability of conviction data than self-report. By comparison, self-reported violence produced odds ratios of 2.02 and 2.18.

The clinical picture is just as serious. Four longitudinal studies of psychiatric populations produced a pooled odds ratio of 3.71 (2.73 to 5.05). The authors recommend that mental health professionals routinely assess cannabis use in people presenting with violent tendencies. They single out those with severe mental illness. Clinicians should also treat continued use as a modifiable risk factor. The paper adds that in England and Wales, substance misuse was common among people with schizophrenia who committed homicide. Cannabis was among the most frequently reported substances.

For clinicians, then, the cannabis violence risk is something to ask about and act on.

What the Authors Say About Causation
Honest reporting means noting what the paper does not claim. The authors state that the link probably reflects several interacting pathways, with no single direct cause. Effect sizes shrank in longitudinal studies of the general population, to 1.17 (1.07 to 1.28). Cross sectional work showed 2.37. Statistical heterogeneity was high, and tests suggested publication bias. The authors cannot exclude residual confounding by alcohol or other drugs. Most studies also lacked detail on how often people used cannabis and at what strength, so dose response could not be tested.

Yet the cannabis violence risk held up under the main checks the authors ran. Results stayed significant after they adjusted for possible publication bias. The longitudinal analyses, they say, suggest the association is not simply down to recall bias or reverse causation. They also note that most included studies predate the rise of high potency products. A risk factor does not need to be the only cause of harm to deserve action.

Heavier Use, Withdrawal and Rising Potency
Professor Smyth argues that drug use escalates when a drug such as cannabis is legalised. He points to North America, where intensive patterns of use rose in particular. Heavier patterns, he says, are the ones more strongly linked to violence. If he is right, the cannabis violence risk grows as use intensifies.

He also highlights cannabis withdrawal, now described in DSM 5 and ICD 11. Irritability is its most common symptom. In his view it likely drives much of the aggression tied to use. That includes violence against women, from intimate partner violence to aggression towards mothers in the home.

The review itself offers supporting mechanisms. Withdrawal can bring irritability, anxiety and restlessness. Regular use also raises the likelihood of paranoia. People may then believe they must defend themselves.

Potency adds to the concern. Writing for the Wall Street Journal, Allysia Finley observed that cannabis today is on average about four times as potent as in 1995. She added that concentrated dabs can contain 20 times as much THC as joints did in the 1960s. Finley also cited the finding that one in six people who start using before the age of 18 will develop cannabis addiction.

Where Harm Reduction Falls Short
Harm reduction asks how a person can use a drug more safely. The Trotta review raises a different question: who else pays? The authors point out that the health effects of cannabis on users have been extensively investigated. Considerably less attention has gone to harms to others, including interpersonal violence.

That gap undercuts the harmless plant message. Roughly twice the odds of violence among users cannot be squared with a claim that cannabis harms no one. Violence linked to cannabis use lands on partners, parents and strangers who never chose the risk.

Raised odds of violence appeared in intimate settings and beyond them. Perpetration within intimate or dating relationships carried odds of 1.22. Violence in other contexts reached 2.79. Smyth adds a sobering comparison. Alcohol, a legal drug, plays an immense role in violence across society, including gender based violence. In his view, that shows legalisation does not protect against it.

Why the Cannabis Violence Risk Demands Accountability
Smyth says the legalisation lobby pushes a narrative that most drug harm flows from the illegal status of drugs. His answer is that the reverse is true. Societies make behaviours such as drug use illegal because of demonstrated risk of harm to the user and to others.

Finley makes a related point. She observes that the stigma once attached to marijuana has vanished. Politicians of both parties, she writes, increasingly treat it as harmless. The public, however, needs an honest discussion of its social and health risks.

That discussion is overdue. Over the same years the paper describes a push towards commercialisation, rising use and rising potency. Meanwhile the evidence on harm to others received comparatively little attention. Those who promoted cannabis as benign now face a plain question. What is their answer to this evidence?

If industry and advocates believe the association is overstated, they can show it. They can fund and publish research with proper exposure detail. The authors name exactly what is missing: frequency, cumulative use, and the balance of THC and CBD. Until that work appears, the burden of proof on the cannabis violence risk has shifted.

Demand Reduction and Prevention Must Lead
The authors describe cannabis use as a potential target for interventions to cut the cannabis violence risk. They say violence should sit alongside other recognised cannabis harms in prevention strategies, public education campaigns and regulatory policies. This applies particularly where cannabis has been legalised or decriminalised. They also call for research testing whether reducing use cuts violent behaviour.

That agenda points upstream. Finley notes that young people now use cannabis more often and in higher doses than earlier generations did. That raises their addiction risk. Prevention that delays or stops uptake can help. So can education that tells the full story, and treatment pathways that support cessation. Each reduces demand before violence linked to cannabis use reaches a household or a street.

The researchers frame violence as a harm to other individuals and society, as well as to the user. Policymakers can keep treating cannabis as a lifestyle product. Or they can treat the cannabis violence risk as the public health matter the evidence says it is.

Dalgarno Institute

Sources: