Drug A - Z

Cannabis

Cannabis is the most commonly used illicit drug in New Zealand. Cannabis is a depressant drug. Depressant drugs do not necessarily make the person feel depressed, rather, they affect the central nervous system by slowing down the messages going to and from the brain to the body. It is possible that cannabis use can trigger psychotic episodes in a person who already has a mental illness.

Marijuana is the most common and least powerful form of cannabis. Marijuana is smoked in hand-rolled cigarettes (joints), in a traditional pipe, or a water pipe (a bong). Marijuana can also be added to various food recipes.

Hashish is dried cannabis resin which comes in small blocks. The blocks range in colour from light brown to nearly black. The concentration of THC in hashish is higher than in marijuana, producing stronger effects. Hash is added to tobacco and smoked, or baked and eaten in foods such as ‘hash cookies’.

Cannabis oil is often created from low grade cannabis leaf (cabbage) in order to extract the THC and create a more potent form of cannabis. Consequently a very small amount can have a strong effect. It is usually spread on the tip or paper of cigarettes and then smoked.

‘Spotting’ is a particularly common way to consume all forms of cannabis in New Zealand. This involves the heating of common kitchen knives, often on a stove. A small amount of cannabis is placed in between the hot knives and the fumes are inhaled.


The effects of any drug vary from person to person.  It depends on many factors including an individual’s size, weight and health, how the drug is taken, how much is taken, whether the person is used to taking it, the person’s mood and whether other drugs are taken.  The effects also depend on the environment in which the drug is used – for example, whether the person is alone, with others, or in a social setting.  The quality and purity of the drug used will also influence its effects.

Immediate effects

Small quantities of cannabis can have effects that last 2-3 hours after smoking and may include:

  • relaxation and loss of inhibition
  • drowsiness
  • increased appetite (the munchies)
  • increased awareness and altered perception of colour, sound, vision, time and space
  • impaired coordination
  • loss of short-term memory
  • altered perception of thought processes (may believe they’ve experienced profound ideas or insights)
  • increased heart rate, low blood pressure, faintness and reddened eyes

In greater quantities

Larger quantities of marijuana make the above effects stronger, and also tend to distort a person’s perceptions.   Very large quantities of marijuana can produce:

  • confusion
  • restlessness
  • feelings of excitement
  • hallucinations
  • anxiety or panic, or detachment from reality
  • decreased reaction time
  • paranoia

Long-term effects

  • traces of THC can remain detectable in urine samples for days, even weeks, after use
  • respiratory illness
  • reduced motivation
  • reduced brain function
  • hormonal imbalances leading to lowered libido and infertility

Tolerance

With regular use, people can develop a mild tolerance to cannabis. This means they need to take more and more to get the same effect.

Dependence

Dependence on cannabis can be psychological or physical, or both.

People who become psychologically dependent on cannabis find that using cannabis becomes far more important than other activities in their life. Cannabis becomes part of their lifestyle (eg reducing stress, increasing relaxation) and some come to depend on it. Some people crave the drug and find it very difficult to stop using it.

Physical dependence occurs when a person’s body has adapted to a drug. The body is used to functioning with the drug present. Heavy and frequent use of cannabis can cause physical dependence.