Cannabis / Marijuana

What are the short and long-term effects
of Marijuana Use?

Some of the short-term effects can include:

 

Effects on Pregnancy

Research has shown that some babies born to women, who abused cannabis during their pregnancies display altered responses to visual stimuli, increased trembling, and a high-pitched cry, which may indicate neurological problems in development. During the preschool years, cannabis-exposed children have been observed to perform tasks involving sustained attention and memory, more poorly than non-exposed children do. In the school years, these children are more likely to exhibit deficits in problem-solving skills, memory, and the ability to remain attentive.

Effects on the Brain

Scientists have learned a lot about how THC acts in the brain to produce many effects. When someone smokes cannabis, THC quickly passes from the lungs into the bloodstream, which distributes the chemical to organs throughout the body, including the brain.

In the brain, THC binds to specific sites called cannabinoid receptors on nerve cells and conditions the activity of those cells. Some parts of the brain area have many cannabinoid receptors and others have very few or none. Many cannabinoid receptors are found in the parts of the brain that controls pleasure, memory, thought, concentration, sensory and time perception, and coordinated movement.

The short-term effects of cannabis can involve problems with memory and learning, distorted perception, problems in thinking and difficulty solving, loss of coordination, and increased heart rate. Research association for long-term cannabis abuse indicate some changes in the brain similar to those obversed after long-term abuse of other major drugs. For example, cannabinoid (THC or artificial forms of THC) withdrawal in highly exposed animals leads to increases in the trigger of the stress-response system and changes in the action of nerve cells containing dopamine. Dopamine neurons are involved in the managing of motivation and reward, and are directly or indirectly affected by all drugs of abuse.

 

Effects on the Heart

A study has indicated that a user's risk of heart attack more than quadruples in the first hour after smoking cannabis. The researchers found that such a response could happen from cannabis’s effects on blood pressure, heart rate and the reduction in the oxygen carrying capacity of blood.

 

Effects on the Lungs

A study of 450 individuals found that people who smoke cannabis often, but do not smoke tobacco have more health issues and miss more days of work than non-smokers. Many of the extra sick days among the cannabis smokers in the study were for respiratory illnesses.

Even irregular abuse can cause burning and stinging of the mouth and throat, often causing a heavy cough. People who smoke cannabis often may have many of the same respiratory issues that tobacco smokers do, such as daily cough and phlegm production, more frequent chest illness, a heightened risk of lung infections, and a greater tendency to obstructed airways. Smoking cannabis possibly increases the chance of developing cancer of the head or neck. A study comprised of 173 cancer patients and 176 healthy individuals carried evidence that cannabis smoking doubled or tripled the risk of these cancers.

Cannabis abuse also has the potential to increase cancer of the lungs and other parts of the respiratory tract because it contains irritants and carcinogens. In fact, cannabis smoke contains 50 to 70 percent more carcinogenic hydrocarbons than does tobacco smoke. It also causes high levels of an enzyme that alters certain hydrocarbons into a carcinogenic form—levels that may accelerate the changes that eventually produce malignant cells. Cannabis users for the most part inhale more deeply and hold their breath longer than tobacco smokers, which increases the lungs' exposure to carcinogenic smoke. These facts show that, puff for puff, smoking cannabis may be more harmful to the lungs than smoking tobacco.

Other Health Effects

Some of cannabis's unfavorable health effects may occur because THC harms the immune system's ability to fight disease. In laboratory experiments that exposed animal and human cells to THC or other cannabis components, the normal disease-preventing reactions of many of the essential types of immune cells were modified. In other studies, mice exposed to THC or related substances were more likely than unexposed mice to develop bacterial infections and tumors.

Effects of Heavy Cannabis Use
on Learning and Social Behavior

Research clearly demonstrates that cannabis has the potential to cause problems in daily life or make a person's existing problems seem to decline. Depression, anxiety, and personality disturbances have been associated with chronic cannabis use. Because cannabis compromises the ability to learn and remember information, the more a person uses cannabis the more he or she is likely to fall behind in accumulating intellectual, job, or social skills. Additionally, research has shown that cannabis’s adverses impact on memory and learning can last for days or weeks even after the intense effects of the drug wear off.

Students who smoke cannabis receive lower grades and are less likely to graduate from high school, compared with their nonsmoking peers. A study of 129 college students found that, among those who smoked the drug at least 27 of the 30 days prior to being surveyed, critical skills related to attention, memory, and learning were significantly impaired, even after the students had not taken the drug for at least 24 hours. These "heavy" cannabis abusers had more trouble maintaining and shifting their attention and in recording, organising, and using information than did others in the study who had abused cannabis no more than 3 of the previous 30 days. Someone who smokes cannabis every day may be functioning at a reduced intellectual level all of the time.

More recently, the same researchers showed that the ability of a group of long-term heavy cannabis abusers to recall words from a list remained impaired for a week after quitting, but returned to normal within 4 weeks. Thus, some cognitive abilities maybe restored in individuals who quit smoking cannabis, even after long-term heavy use.

Workers who smoke cannabis are more likely than their co-workers to have problems on the job. Some studies associate workers' cannabis smoking with increased absences, tardiness, accidents, workers' compensation claims, and job turnover. A study among postal workers found that employees who tested positive for cannabis on a pre-employment urine drug test had 55 percent more industrial accidents, 85 percent more injuries, and a 75-percent increase in absenteeism compared with those who tested negative for cannabis use. In another study, heavy cannabis abusers reported that the drug impaired several important measures of life achievement including cognitive abilities, career status, social life, and physical and mental health.

Addictive Potential

Long-term cannabis abuse can lead to addiction for some people; that is, they abuse the drug compulsively even though it interferes with family, school, work, and recreational activities. Drug craving and withdrawal symptoms can make it hard for long-term cannabis smokers to stop abusing the drug. People trying to quit report irritability, sleeplessness, and anxiety. They also display increased aggression on psychological tests, peaking approximately one week after the last use of the drug.

Genetic Vulnerability

Scientists have found that whether an individual has positive or negative sensations after smoking cannabis can be influenced by heredity. A 1997 study demonstrated that identical male twins were more likely than non-identical male twins to report similar responses to cannabis abuse, indicating a genetic basis for their response to the drug. (Identical twins share all of their genes.)

It also was discovered that the twins sharing of family environment before age 18 had no detectable influence on their response to cannabis. Certain environmental factors, however, such as the availability of cannabis, expectations about how the drug would affect them, the influence of friends and social contacts, and other factors that differentiate experiences of identical twins were found to have an important effect.

 

Are there any groups of people
at higher risk then others?

YES

Treatment options

There are quite a number of treatment options available for drug dependence in Australia. These vary in their aims and outcomes. The majority of programs implement strategies that have an aim of reducing the harms and risks related to the person's drug dependence.

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