What smoking cannabis really does to your mind: Experts reveal the surprising effects this 4/20

• THC in cannabis affects how different parts of your brain communicate
• This causes effects ranging from time dilation to paranoia and anxiety.

As 4/20 approaches once again, the unmistakable smell of cannabis will soon fill parks and student housing across the country.

Although it remains illegal in the UK, the drug is regularly smoked, consumed or vaped by around 3.1 million people.

But understanding the scientific effects of cannabis on your mind can be tricky, especially if you’ve just smoked it.

From increasing your libido to triggering auditory hallucinations, not all of the effects of cannabis are what you might expect.

So whether you’re celebrating this weekend or not, MailOnline asked experts what your brain actually looks like on drugs.

Cannabis contains two chemicals that are largely responsible for the effects you experience: CBD (cannabidiol) and THC (tetrahydrocannabinol).

These are capable of getting us high because they are similar to the chemicals our brains produce naturally.

Throughout our brain and body, we have a complex system of chemical signals and receptors called the endocannabinoid system.

Dr Will Lawn, a psychologist from King’s College London, told MailOnline it was like a dial that increases or decreases the level of communication between parts of the brain.

Parts of this system called CB1 receptors sit at the junctions of our nerves like traffic lights, slowing or speeding up the flow of the brain’s communication chemicals.

When you consume weed, THC sticks to these CB1 receptors and inhibits the release of certain neurotransmitters like dopamine and glutamate.

Like a faulty traffic light, this significantly slows down circulation between different regions of the brain and triggers the psychoactive elements of the high.

This has downstream effects throughout the body, but what makes weed hit you the way it does is entirely due to where these CB1 receptors are most commonly found in the brain.

Dr Lawn says: “We find that they are densely expressed in the cerebellum, in the hippocampus and also in some limbic regions, including the amygdala.”

“The cerebellum is crucial for supporting movement, the hippocampus is crucial for supporting movement, and the limbic system is crucial for emotional responses.”

“You will recognize that these are three cognitive processes that are significantly affected by cannabis.”

Short-term memory

Beyond the general feeling of “high” and relaxation, one of the most common effects of cannabis use is a significant reduction in short-term memory.

If you’ve ever watched the classic stoner movie “Dude, Where’s My Car?” ”, you’ll recognize the stereotype of the awkward, constantly confused stoner.

Since the 1970s, researchers have shown that people have a really hard time retaining and working with the information in their short-term memory when they’re high.

If you still remember it, it’s because THC disrupts signaling in the hippocampus and interferes with the way your brain processes memory.

This disrupts “working memory,” the part of the mind that allows for rapid retrieval and manipulation of information.

Studies have shown that this causes difficulty with attention and concentration in some users.

Oddly enough, however, studies have also shown that regular heavy users improve their concentration after smoking because they are used to the effects.

Although we know for certain that cannabis use affects memory while in use, the evidence for long-term effects is much less certain.

Dr. Lawn says there is some evidence that long-term use has a small effect on verbal memory, but most lingering effects tend to disappear once the user stops smoking.

“Many cannabis users have high intelligence and very good memories,” says Dr. Lawn.

“When you compare heavy cannabis users and non-users, you will see a lot of overlap.”

There may be effects on cognitive function and long-term memory, Dr. Lawn says, but these effects tend to be very small and there is wide variation between different users.

Slows down the perception of time

If you’ve ever eaten too many pot brownies, perhaps on an ill-advised trip to Amsterdam, this effect will be all too familiar.

Cannabis users report that time seems to stretch on forever as minutes begin to feel like hours.

Research has shown that consuming cannabis produces an effect called time dilation.

In one study, participants were given either a placebo or a THC injection and asked to press a button once per second 70 times.

Those who received the cannabis dose were significantly slower than their sober counterparts, pressing the button every 1.73 seconds compared to every 1.49 seconds.

Other research has shown that, even when high, cannabis users tend to significantly overestimate the amount of time that has passed.

Other experiments show that reaction times decreased and decision-making gaps increased after participants smoked weed.

Scientists aren’t sure exactly why this happens, but one theory suggests that THC binds to receptors located in a part of our brain responsible for our internal biological clock.

This region, called the suprachiasmatic nucleus, is essential for maintaining our circadian rhythm.

The disruptive effects of THC could send this region into a tailspin, leaving us perplexed as to the passage of time.

Creativity

From writers like Seth Rogan to painters like Salvador Dali, many people use cannabis to stimulate their creativity.

After smoking, you may feel more in touch with your creative side, but the science is more complex.

Cannabis users tend to score higher on self-reported creativity and perform better on measures of “convergent thinking.”

But once you factor in cannabis users’ openness to new experiences, these effects disappear — meaning it’s not cannabis that makes people more creative.

To explain why people feel more creative when they’re high, we need to examine how cannabis affects their response to creativity.

Although research shows no evidence that cannabis stimulates creativity, it makes people who use it feel good and thus perceive ideas as more creative.

Researchers found that people tended to view their own cannabis-fueled ideas as more creative than their sober ideas, even when they were sober.

Likewise, high participants tended to view others’ ideas as more creative than when they were sober.

So while weed won’t fill you with brilliant ideas, it might give you the confidence and enthusiasm to follow through on them.

Pain

Cannabis is not only used for recreational purposes and there is now a…