One puff of cannabis can relieve stress but more is bad


A new study has confirmed that small doses of medical marijuana do help relieve stress – but any more than a couple of puffs has the opposite effect.

Researchers in Chicago split 42 people into three groups, and gave them each a batch of THC capsules – one equivalent to a couple of puffs, one equivalent to half a joint, and one a placebo. 

THC, or tetrahydrocannabinol, is the psychoactive compound in cannabis which makes users feel ‘high’.

They found that very low doses lessened anxiety and jitters when faced with a public-speaking task.

However, a stronger dose – enough to trigger a mild high – increased anxiety levels.

The researchers said it is one of the most rigorous investigations into the widely accepted – but untested – idea that THC relieves stress, and at what level.   

The Chicago researchers said their study is one of the most rigorous investigations into the widely accepted – but untested – idea that THC (the ‘high’ property in cannabis) relieves stress

‘We found that THC at low doses reduced stress, while higher doses had the opposite effect, underscoring the importance of dose when it comes to THC and its effects,’ said lead author Emma Childs, associate professor of psychiatry in the College of Medicine at the University of Illinois at Chicago.

Both medical and recreational use of marijuana are legal in Colorado, Washington, Alaska, Oregon, Nevada, California, Maine and Massachusetts.

Restricted for medical use only are: Montana, North Dakota, Arizona, New Mexico, Arkansas, Louisiana, Florida, Illinois, Minnesota, Michigan, Ohio, New York, Pennsylvania, Maryland, District of Columbia, Vermont, New Hampshire, New Jersey, Rhode Island, Connecticut, Delaware and Hawaii. 

Childs and her colleagues recruited 42 healthy volunteers 18 to 40 years old who had some experience with cannabis use but who were not daily users.

Participants were randomly divided into three groups.

The low-dose group received a capsule containing 7.5 milligrams of THC, which is equivalent to one or two puffs on a medical-grade joint.

The moderate-dose group received a capsule containing 12.5 milligrams of THC, which comes closer to half a joint. 

The placebo group received a capsule containing no THC. 

Neither the participants nor the researchers knew who was in each group.

‘The doses used in the study produce effects that are equivalent to only a few puffs of a cannabis cigarette,’ said Childs, noting that it is difficult to compare doses of smoked cannabis to doses of ingested THC. 

‘We didn’t want to include a much larger dose, because we wanted to avoid potential adverse effects or cardiovascular effects that can result from higher doses of THC.’

Participants attended two four-hour sessions at the University of Chicago, five days apart. 

WHAT IS CANNABIDIOL? 

Cannabidiol (CBD) is a drug derived from cannabis.

The medicine has the psycho-active elements of marijuana, THC, removed.

THC is what gives marijuana users their ‘high’.

The drug offers hope for thousands of children living with untreatable epilepsy.

Cannabidiol halved the seizures suffered by children with a severe form of the condition called Dravet syndrome. 

Experts at New York University and Great Ormond Street children’s hospital in London said the results could make a ‘considerable difference’ to adults and children suffering with epilepsy. 

In five percent of patients given the oil the debilitating fits stopped altogether. 

At each session, they took their capsule and then relaxed for two hours to allow the THC to be absorbed into the bloodstream.

During one session, participants were asked to spend 10 minutes preparing for a mock job interview. 

They were then subjected to a five-minute interview with lab assistants who did not offer any feedback, verbally or through body language, although video display was visible to the participant, showing their performance. 

Participants were then instructed to count backwards from a five-digit number by subtracting 13, for five minutes—a task that is ‘very reliably stress-inducing,’ Childs said.

In their second visit, participants were asked to talk to lab assistants about a favorite book or movie for five minutes and then play solitaire for another five minutes.

Before, during and after each of the two activities, participants rated their stress levels and feelings about the tasks. Blood pressure, heart rate, and cortisol, a key stress hormone, were measured at intervals.

The participants who received 7.5 milligrams of THC reported less stress after the psychosocial test than those given a placebo, and their stress levels dissipated faster after the test.

Participants who received 12.5 milligrams of THC before the two tasks reported greater negative mood before and throughout the task, and were more likely to rate the psychosocial task as ‘challenging’ and ‘threatening’ beforehand. Participants who received this dose also had more pauses during the mock interview compared to those in the placebo group.

There were no significant differences in participants’ blood pressure, heart rate or cortisol levels—before, during or after the doses or the tasks.

‘Our findings provide some support for the common claim that cannabis is used to reduce stress and relieve tension and anxiety,’ Childs said. 

‘At the same time, our finding that participants in the higher THC group reported small but significant increases in anxiety and negative mood throughout the test supports the idea that THC can also produce the opposite effect.’

‘Studies like these—examining the effects of cannabis and its pharmacological constituents under controlled conditions—are extremely important, considering the widespread use of cannabis for both medical and non-medical purposes,’ she said. 

‘Unfortunately, significant regulatory obstacles make it extremely difficult to conduct this type of research—with the result that cannabis is now widely available for medical purposes with minimal scientific foundation.’