what happens if you smoke weed once

What Happens If You Smoke Marijuana?

Reactions with pot can vary widely

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Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital.

Sean Gallup Collection / Getty Images News

The reaction you may have when trying marijuana can vary dramatically based on many factors.   Some people report not feeling anything at all when they smoke marijuana. In other cases, people report feeling relaxed or “high.”

Some people who use marijuana report having sudden feelings of anxiety and paranoid thoughts and that might be caused by trying a higher potency marijuana, according to the National Institute on Drug Abuse.  

Research also shows that regular use of marijuana is linked to an increased risk of depression, anxiety and a loss of motivation or drive.   You may feel “dopey” on the drug, which is when you begin to lose interest in activities that you might have previously enjoyed or you may lose the ability to grasp concepts easily.

Short-Term Discomforts of Using Weed

The effects of using marijuana can be unpredictable, especially when it is mixed with other drugs, research shows. You may feel relaxed on the drug, but other things you might not be expecting with pot use can include rapid heart rate and other unpleasantries.  

  • Dry mouth
  • Swollen eyelids
  • Bloodshot eyes
  • Loss of coordination
  • Accelerated heart rate

Short-Term Hazards

As with any drug or substance that can alter perception, logic and usual behavior, there are several short-term hazards of using marijuana from impairing driving abilities to memory loss.  

  • Learning difficulties
  • Lack of attention and focus
  • Poor driving skills
  • Anxiety and paranoia
  • Impaired memory
  • Difficulty in thinking

Long-Term Hazards

Any drug that is taken over a prolonged period of time can have an effect on your health. Several of the physical barriers that can occur range from infertility problems to overall brain functions.  

  • An increased risk of developing lung, head, and neck cancers
  • Lack of motivation
  • Decreased sperm count in men
  • Irregular menstruation in women
  • Respiratory problems
  • Heightened risk of infections, especially the lungs
  • Poor short-term memory recall
  • Inability to shift attention normally
  • Inability to understand complex information​

Unpredictable Reactions

The National Institute on Drug Abuse reports that marijuana can affect each person differently according to their own body chemistry and the type of pot used.   Some people can use weed and never have any negative reactions while others may try it and get entirely freaked out by the experience.

  • Your biology (genetic makeup)
  • Marijuana’s strength (amount of active ingredient THC)
  • Previous experience with the drug
  • How it’s taken (smoked versus ingested)
  • Whether alcohol or other drugs are taken too​

Not Your Grandfather’s Pot

Studies have found that the marijuana available today is much different in terms of potency compared to what was generally available in the 1960s when the use of the drug became widespread in the United States.  

Today’s strains of the plant contain much more of the active ingredient in marijuana: tetrahydrocannabinol or THC, researchers say.   That makes today’s weed much more potent than that smoked by the hippies and flower children of the Woodstock generation.

How marijuana affects the individual user depends on many different factors, including body chemistry and the potency of the drug.

Smoking cannabis just once can change a teenager’s brain

Scientists say it could have serious implications

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Teenagers who use cannabis just once or twice may end up with changes to the structure of their brain, scientists have warned.

A study, conducted by researchers at Swinburne University of Technology in Melbourne, Australia, found that there were clear differences on brain scans between teens who said they had smoked cannabis a couple of times and those who had never tried it.

Until now, research using animals to study the effects of cannabis on the brain have shown effects at low levels, leading researchers to believe that changes might occur during early stages of cannabis use.

However, the study’s lead author, Catherine Orr, says she “was surprised by the extent of the effects”.

The researchers analysed images from 46 14-year-olds who said they had used marijuana once or twice, as well as images from 46 teens who had never tried it, taking into consideration age, sex, IQ, socioeconomic status and use of alcohol or tobacco.

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Upon analysing the teens’ brain scans, the researchers found clear differences between the two groups, which they suspected were due to low-level cannabis use.

At this stage, the scientists couldn’t prove that marijuana led to the differences seen in the scans and acknowledged that it was possible those who chose to use marijuana had different brain structures to begin with.

To address this, the researchers analysed scans from a third group of teens that had not tried marijuana before they had their brain scans at age 14.

By the age of 16, 69 of the participants said they had used marijuana at least 10 times but their brain scans at age 14 looked no different to the brain scans of other teens who had not taken up cannabis.

This meant there could not be any inborn brain difference that predicts a person would later become a cannabis user.

Taking the ayahuasca hallucinogenic drug – in pictures

1 /7 Taking the ayahuasca hallucinogenic drug – in pictures

Taking the ayahuasca hallucinogenic drug – in pictures

Taking the ayahuasca hallucinogenic drug – in pictures

Taking the ayahuasca hallucinogenic drug – in pictures

Taking the ayahuasca hallucinogenic drug – in pictures

Taking the ayahuasca hallucinogenic drug – in pictures

Taking the ayahuasca hallucinogenic drug – in pictures

Taking the ayahuasca hallucinogenic drug – in pictures

What’s more, the scientists discovered there were widespread increases in the volume of grey matter – which is made up of nerve cell bodies and involved in sensory perception and muscle control – in brain regions among those who had smoked marijuana.

According to the researchers, this kind of alteration to the structure of the brain could have serious implications.

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“In our sample of cannabis users, the greater volumes in the affected parts of the brain were associated with reductions in psychomotor sped and perceptual reasoning and with increased levels of anxiety two years later,” Orr said.

However, the higher volume of grey matter in cannabinoid-rich regions of the brain could be related to a normal process called “pruning” which may go awry when teens use marijuana.

As young brains develop, unnecessary or defective neurons are pruned away, Orr explained. But, when the system doesn’t work correctly, those cells remain in place.

With rates of cannabis use among adolescents increasing – it’s the most frequently used drug in Europe – concurrent with changes in the legal status of marijuana and societal attitudes regarding its use, the scientists believe the new findings are a step forward in understanding the impact it can have on developing brains, but accept that more research needs to be done.

1 /1 Smoking cannabis just once can change a teenager’s brain

Smoking cannabis just once can change a teenager’s brain

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Scientists say it could have serious implications