Parents | Understanding Cannabis

Cannabis
is the most widely used illicit drug in New Zealand. Our teenagers use it more than teens anywhere else in the world. By age seventeen 25% have tried it and 20% of Maori rangatahi, 10% of non-Maori youth, meet the criteria for abuse or dependence.

What is it?

Cannabis is a depressant, meaning that it slows down the messages between the brain and the body. The ‘high' from smoking cannabis normally takes effect within minutes and can last for 2 to 3 hours.
Cannabis contains over 400 chemicals and around 60 of them are psychoactive (mind altering). The most studied of these is delta-9-tetrahydrocannabinol, THC.

The half life of cannabis, (the time it takes for half the chemicals to leave the body) is 3-5 days, meaning an ever reducing amount remains in our system for about 5 weeks after the ‘high'.

How is it used?

The most common way is by smoking it rolled into cigarettes (joints) or through a pipe or water bong. It is also ‘spotted' which involves rapidly heating small portions of cannabis on a very hot surface, such as a knife, and the fumes inhaled. Utensils used this way will soon tarnish with distinctive heat marks.

Short term effects

Many get euphoria, a ‘high' feeling which some call a ‘buzz'. It can help relax people and often creates an intensified sensory experience. However, it can also cause red eyes, an elevated appetite, a level of paranoia, confusion, mild hallucinations, impaired coordination, restlessness and depression.

Long term effects

It affects both mental and physical health. Concentration declines, short term memory and ability to learn is impaired, and motivation diminishes over time.
Also presents with similar health risks as tobacco smoking and affects the respiratory system, especially since it is inhaled more deeply and for longer.

Why is it particularly risky for adolescents?

1. Puberty is that period of life when most harm can be done, because:

• of the speed of changes going on in the brain;
• the 4 Is of emotional maturity are being developed: independence, individuality, intimacy and integrity; 
• the prefrontal cortex is being formed and goes on developing until age 25; and 
• it impairs short term memory, impeding new learning at that time in life when the brain is most receptive to learning.

2. The THC in Cannabis is lipophillic (fat loving), and the greatest concentrations of fat are in the brain where an ever-diminishing amount of THC are stored for up to 5 weeks at a time. The THC continues to impact on brain function throughout the five weeks after the ‘high'.

Single Photon Emission Computerized Tomography views of a brain.

Normal 16 year old brain	16 year old brain after 2 years of daily cannabis use

The apparent holes are areas where there is no blood flow and indicate those parts of the brain that are no longer functioning. There is recovery when drug use stops, though never full recovery. 

Summary

Cannabis is one of the few drugs stored in the body for any length of time, but being stored in the fat content of every brain cell makes it a particular problem. It impairs short term memory, limits learning, exacerbates criminality, decreases motivation, harms prefrontal cortex development and can trigger a psychotic episode in those pre-disposed to mental disorders, such as schizophrenia.

Reference: www.brainplace.com