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Drug Addiction

MARIJUANA - a patient's guide


Marijuana is one of the most commonly used illegal drugs. This article looks the health risks related to cannabis use.


  • Marijuana is the most common illegal drug used in many countries
  • One in three people are believed to have tried it
  • Occasional use is not clearly linked to health problems
  • Long term and daily use can lead to respiratory problems, and memory loss
  • There is controversy over using the drug to treat some health conditions
  • There is debate over whether cannabis use leads to harder drugs
  • Heavy users develop a tolerance to cannabis
  • Rehabilitation programmes are now available in most cities

What is it?

Marijuana is a popular recreational drug. It is the most common illegal drug used in many countries around the world.

Research suggests one in three people aged between 14 to 34 have tried it at least once. In the USA and Australia about 10 percent of those who have used it become daily users, and up to 30 percent use it on a weekly basis.

The effective ingredient in cannabis which makes a person feel high is called THC (Delta-9 tetrahydrocannabinol). However, the drug is actually a depressant not a stimulant.

The THC content is strongest in the flowering buds, and lower in the leaves. Dried cannabis, and hashish made from compressed cannabis, is mainly smoked, though it can also be eaten.

A cannabis joint contains between .5g and 1.0g of cannabis and the amount of THC can vary between 20 and 70 percent.

The marijuana acts on regions of the brain responsible for thinking, memory, pain, and movement coordination.

The mood change from smoking cannabis can occur within a few minutes and last up to five hours. The drug can stay in the body for up to six weeks because it is stored in body fat.

Smoking marijuana may cause a feeling of euphoria, increase the heart rate, the appetite and make someone laugh or talk more than usual. These feelings will later subside, causing drowsiness.

Long-term drug users may need to smoke more of the drug to achieve a high than those who only use it occasionally.

Heavy users run the risk of long-term health effects. Occasional users of cannabis are unlikely to damage their health.

There is controversy over using the drug to relieve some medical conditions. These include nausea from chemotherapy, glaucoma, anorexia, and mood disorders. It is less commonly used to treat asthma, Crohn's disease and post-traumatic stress disorder.

The use of marijuana for medical purposes has been legalised in California and Arizona. However, there have been no strong studies to prove the drug is effective in treating health conditions.

What are the warning signs?

Not everyone who uses marijuana becomes addicted, but a small percentage of people who crave and use the drug compulsively may be dependent on it.

About one in 10 cannabis users become dependent on the drug.

If you are experiencing any of the following problems you may be dependent:

  • Becoming more forgetful
  • Lack of energy and motivation
  • Smoking at risky times or places
  • Needing a joint to start the day
  • Not being able to have a drug free day
  • Driving under the influence of cannabis
  • Experiencing paranoia or panic attacks
  • Needing more marijuana to make you high

What are the health risks?

People who smoke a lot of cannabis or use the drug on a daily basis run the biggest health risks.

They may experience problems with their short-term memory, attention span, sex drive, motivation, learning new concepts, and their respiratory system.

Large does can also cause confusion and panic attacks. These effects are also common in new users and this is a common reason for not using the drug.

Cannabis smoking can increase the heart rate by up to 50 percent soon after it is used.

People's coordination and movement can be impaired during a major drug high. This means a user may not be able to drive or operate machinery properly. A car accident could be a serious consequence of being high on cannabis.

Studies have shown marijuana can impair driving skills, but it's believed cannabis users are more aware of their condition and less likely to take risks on the road, which is common with alcohol use. However, marijuana use can strengthen the effects of alcohol and lead to dangerous driving.

Long term and heavy cannabis use is linked to an increase in respiratory problems, such as poorer lung function, and more coughing and wheezing.

One study has shown that smokers of both tobacco and marijuana have the largest number of respiratory problems.

It is claimed that heavy cannabis smoking can lead to lung cancer. However, there have been no proven cases of this as yet. There have been reports of cancers in the respiratory tract in young heavy cannabis users, and these cancers are rare among adults under 60. In theory it is possible for cannabis smoke to cause cancer and more studies are necessary.

Heavy cannabis users can develop tolerance to the drug and need larger and larger amounts to make them high.

Cannabis itself has low toxicity. There have been no confirmed cases of deaths from marijuana poisoning.

It is also believed that marijuana use can lead to the abuse of other drugs like cocaine or heroine, but there continues to be debate about this.

Research shows heavy teenage cannabis users do not do as well in high school compared with non-users.

Large doses of cannabis can cause memory loss, delusions, and hallucinations. Research suggests that cannabis use can lead to schizophrenia in a person who already has a predisposition to the mental condition. It is believed these people would have developed schizophrenia regardless of whether they used cannabis or not.

It is hard to know how cannabis can effect an unborn child because long-term studies are difficult given the illegal nature of the drug. Some studies have shown cannabis use by pregnant women has been linked to babies being born with low birth weights. Initial data from another study show children of marijuana users may have trouble with memory and concentration. It is unlikely that cannabis can cause birth defects.

Three studies have found an increased risk of leukaemia among children whose mothers smoked marijuana, and further research is necessary to confirm a link.

Getting help

Treatment programmes for marijuana addiction are a recent development. Now most cities offer some help for people who want to quit.

There are no medications to help users give up. Rehabilitation programmes involve counselling and group therapy.

There are also programmes specifically designed to help teenagers who are addicted.

Suggestions for cutting down alone include:

  • Place a limit on how much you smoke
  • Avoid people and places which make you want to smoke marijuana
  • Find a support person to cut down with
  • Keep a diary of how much you using
  • Have some smoke free days a week
  • Reward yourself for sticking to your goal.

Withdrawal symptoms include irritability, mood swings, headaches, and problems sleeping.

Future trends

Researchers are looking at whether marijuana has a role in treating wasting syndrome which affects people with AIDS.

Researchers are also developing new ways to help marijuana users stop taking the drug.

Where to go for help?

Local hospitals have drug and alcohol centres which help people with cannabis addiction.

Odyssey House runs inpatient drug rehabilitation programmes in Auckland and Christchurch for people with severe marijuana addictions. Ph Auckland 09 623 0228 or Christchurch 03 358 0950.

Marijuana Anonymous offers a 12-step programme based on the same one used by Alcoholics Anonymous. Ph Auckland 09 846 6822.

See also:

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