London Daily

Focus on the big picture.
Wednesday, Jul 30, 2025

Does cannabis lead to harder drug use?

Leading Democrats have clashed over whether legalising cannabis leads to harder drug use - what's the evidence?

There's strong disagreement among Democratic contenders for the US presidency about legalising cannabis and it's been a flashpoint in their televised debates.

Joe Biden, currently the leading contender in the race, won't be drawn either way. He wants more evidence about whether using it could act as a "gateway" to the use of harder drugs before it's legalised throughout the US.

"Before I legalise it nationally," said Biden, "I want to make sure we know a lot more about the science behind it."

But other Democrats, such as Cory Booker and Kamala Harris, have attacked this approach, saying the evidence is clear-cut and that cannabis use should be legalised.

Senator Booker, who supports legalisation, joked that he thought Mr Biden "might have been high" when he said he opposed legalisation. Senator Harris has said: "Let's be clear; marijuana isn't a gateway drug and should be legalised."

Other senior Democrats such as Bernie Sanders and Elizabeth Warren also say they support legalisation.

Polling by the Pew Research Center shows that public support for legalisation has steadily increased in the last decade, with two-thirds of Americans now supporting it.


What does the science say?

Some 33 states have legalised medical cannabis, while 11 states and Washington DC have also legalised recreational use. But cannabis use remains illegal at the federal level.

So is there evidence legalising cannabis could lead to the use of more dangerous substances?

The US government's own National Institute on Drug Abuse states that "some research suggests that marijuana use is likely to precede use of other licit and illicit substances". It cites experiments on animals that show increased responsiveness to other drugs after being exposed to substances containing cannabis.

However, it adds that cannabis is not unique - alcohol and nicotine have a similar effect. And it states that the majority of people who use marijuana do not go on to use other, "harder" substances.

Denise Kandel, from the Mailman School of Public Health in New York, says research on animals shows changes in the way the brain responds to cocaine after exposure to alcohol, nicotine or marijuana.

She also says: "You are never able to establish a clear connection between using marijuana and using other drugs because there are so many other contributing factors that you can't control for in the research."

A paper published recently by the American Journal of Drug and Alcohol Abuse says: "Evidence of the impact of cannabis liberalisation on the use of other substances is inconclusive. We have limited evidence of how either alcohol or tobacco use has been impacted."


What's happened in states that have legalised?

There's evidence that in states where cannabis has been legalised, usage of the drug among teenagers has decreased - or stayed the same.

There's also research indicating that among adults aged 26 and older, legalisation leads to more rather than less cannabis use.

And evidence has also emerged linking regular use of stronger strains of cannabis to an increased risk of mental health conditions, particularly among younger people.

Washington, Oregon, Alaska and Colorado all legalised between 2014 and 2016, among the first US states to do so. Do they show any particular trends for the use of harder drugs?

The US authorities collect data for drug overdose deaths, and between 2013 and 2017, 35 states had significant increases in deaths over that period. Alaska is among these, but Washington, Colorado and Oregon are not.

The majority of these fatal overdoses are due to opioids - excluding methadone.

Alaska apart, opioid deaths in Colorado, Washington and Oregon did not increase significantly between 2013 and 2016, the last year for which data is available.

And estimates for cocaine use in the four states where marijuana is legal show it was above the national average from 2013 to 2016. But it was also higher in three of these states in 2012 before legalisation had taken effect.

Given that there are many different factors in each state that affect drug use like availability and supply, treatment and rehabilitation programmes, law enforcement priorities and social and economic conditions, it's hard to draw firm conclusions.

So more research may well be needed over a longer period to identify if there are clear trends around the use of other drugs in places where cannabis has been legalised.

Newsletter

Related Articles

0:00
0:00
Close
Former Judge Charged After Drunk Driving Crash Kills Comedian in Brazil
Jeff Bezos hasn’t paid a dollar in taxes for decades. He makes billions and pays $0 in taxes, LEGALLY
China Increases Use of Exit Bans Amid Rising U.S. Tensions
IMF Upgrades Global Growth Forecast as Weaker Dollar Supports Outlook
Procter & Gamble to Raise U.S. Prices to Offset One‑Billion‑Dollar Tariff Cost
House Republicans Move to Defund OECD Over Global Tax Dispute
Botswana Seeks Controlling Stake in De Beers as Anglo American Prepares Exit
Trump Administration Proposes Repeal of Obama‑Era Endangerment Finding, Dismantling Regulatory Basis for CO₂ Emissions Limits
France Opens Criminal Investigation into X Over Algorithm Manipulation Allegations
A family has been arrested in the UK for displaying the British flag
Mel Gibson refuses to work with Robert De Niro, saying, "Keep that woke clown away from me."
Trump Steamrolls EU in Landmark Trade Win: US–EU Trade Deal Imposes 15% Tariff on European Imports
ChatGPT CEO Sam Altman says people share personal info with ChatGPT but don’t know chats can be used as court evidence in legal cases.
The British propaganda channel BBC News lies again.
Deputy attorney general's second day of meeting with Ghislaine Maxwell has concluded
Controversial March in Switzerland Features Men Dressed in Nazi Uniforms
Politics is a good business: Barack Obama’s Reported Net Worth Growth, 1990–2025
Thai Civilian Death Toll Rises to 12 in Cambodian Cross-Border Attacks
TSUNAMI: Trump Just Crossed the Rubicon—And There’s No Turning Back
Over 120 Criminal Cases Dismissed in Boston Amid Public Defender Shortage
UN's Top Court Declares Environmental Protection a Legal Obligation Under International Law
"Crazy Thing": OpenAI's Sam Altman Warns Of AI Voice Fraud Crisis In Banking
The Podcaster Who Accidentally Revealed He Earns Over $10 Million a Year
Trump Announces $550 Billion Japanese Investment and New Trade Agreements with Indonesia and the Philippines
US Treasury Secretary Calls for Institutional Review of Federal Reserve Amid AI‑Driven Growth Expectations
UK Government Considers Dropping Demand for Apple Encryption Backdoor
Severe Flooding in South Korea Claims Lives Amid Ongoing Rescue Operations
Japanese Man Discovers Family Connection Through DNA Testing After Decades of Separation
Russia Signals Openness to Ukraine Peace Talks Amid Escalating Drone Warfare
Switzerland Implements Ban on Mammography Screening
Japanese Prime Minister Vows to Stay After Coalition Loses Upper House Majority
Pogacar Extends Dominance with Stage Fifteen Triumph at Tour de France
CEO Resigns Amid Controversy Over Relationship with HR Executive
Man Dies After Being Pulled Into MRI Machine Due to Metal Chain in New York Clinic
NVIDIA Achieves $4 Trillion Valuation Amid AI Demand
US Revokes Visas of Brazilian Corrupted Judges Amid Fake Bolsonaro Investigation
U.S. Congress Approves Rescissions Act Cutting Federal Funding for NPR and PBS
North Korea Restricts Foreign Tourist Access to New Seaside Resort
Brazil's Supreme Court Imposes Radical Restrictions on Former President Bolsonaro
Centrist Criticism of von der Leyen Resurfaces as she Survives EU Confidence Vote
Judge Criticizes DOJ Over Secrecy in Dropping Charges Against Gang Leader
Apple Closes $16.5 Billion Tax Dispute With Ireland
Von der Leyen Faces Setback Over €2 Trillion EU Budget Proposal
UK and Germany Collaborate on Global Military Equipment Sales
Trump Plans Over 10% Tariffs on African and Caribbean Nations
Flying Taxi CEO Reclaims Billionaire Status After Stock Surge
Epstein Files Deepen Republican Party Divide
Zuckerberg Faces $8 Billion Privacy Lawsuit From Meta Shareholders
FIFA Pressured to Rethink World Cup Calendar Due to Climate Change
SpaceX Nears $400 Billion Valuation With New Share Sale
×