Cannabis, a Class C controlled drug, is composed of dried plant material from the Indian hemp plant Cannabis Sativa. The active ingredient is THC (tetrahydracannabinol). Other forms of cannabis are hashish (dried cannabis resin and compressed flowers) and hashish oil (oil extracted from the plant with an organic solvent). Hashish and hashish oil contain significantly higher levels of THC and are Class B controlled drugs. New Zealand grown cannabis also contains higher levels of THC than that grown overseas. The cultivation, possession and sale of both Class C and Class B drugs is illegal in New Zealand, the penalty can range from 3 months to 14 years imprisonment, along with the possibility of a fine.

Why do people use cannabis?

Cannabis is a Central Nervous System depressant. In small doses it relaxes the user and produces feelings of euphoria and increased social confidence. Sometimes people use cannabis to escape their problems (unfortunately they always come back!). Young people often experience peer pressure to 'share a joint' with friends in a social setting, in the same way they feel social pressure to use tobacco or alcohol.

So what's the problem?

The occasional recreational use of a small amount of cannabis is unlikely to cause problems, but higher or more frequent doses can:

  • Increase the risk of accident due to impaired balance and co-ordination, reduction in attention, short-term memory and reaction time, slowed information processing and motor performance and impaired perception of time
  • Study or work can be affected by the reduction in concentration, short-term memory and information processing

Long-term effects of use include:

  • Increased risk of respiratory diseases, including acute and chronic bronchitis, lung cancer and cancers of the mouth, throat and upper respiratory tract (cannabis smoke is more irritating to the respiratory tract than tobacco smoke and combining the two increases the risk)
  • The possibility of “Amotivational Syndrome” including reduction in energy, drive and motivation – work, study and active hobbies can suffer
  • In some vulnerable individuals a short-term cannabis- induced psychosis can occur, producing confusion, amnesia, delusions, hallucinations

Effects on mental health

A small percentage of people experience adverse psychological effects from occasional or fi rst time cannabis use.Some people experience their f rst ever panic attack after/ during exposure to cannabis. Heavy or frequent users are at higher risk of the following –

  • Anxiety, panic, paranoia, fear of going mad
  • Depression
  • Psychotic symptoms, including delusions and hallucinations (at high dose)


The possibility of developing a dependence on cannabis is very low for occasional users; however frequent users can develop both a physical and psychological dependence. This results in an increased amount of cannabis being used to “feel normal”. The anxiety, agitation and depression often caused by heavy use of cannabis are managed by increasing the frequency and amount used. This in turn can lead to further problems.


Use of cannabis:

  • Can have a negative impact on interpersonal relationships. Intoxication with cannabis can result in communication difficulties and lack of responsibility in attending to important obligations
  • Heavy users can find they are facing increasing financial difficulties due to the cost of their habit and time taken from work or study
  • Cannabis use is illegal in New Zealand. Users face the possibility of criminal conviction


When frequent, heavy users of cannabis decide to stop using they can experience a mild withdrawal syndrome, which may include some of the following symptoms –

  • Anxiety, restlessness, agitation
  • Irritability
  • Insomnia
  • Anorexia (temporary)
  • Diarrhoea
  • Hot flushes/sweating
  • Flu type symptoms

The symptoms largely resolve in one week but may persist in a milder form for up to one month.


You could make an appointment at your local Alcohol & Drug Service (there is one attached to each hospital). You could talk to a counsellor at your campus Student Counselling Service. We can provide information and support to make sure you get the help you need.

A final thought:                

"What hashish gives with one hand it takes away with the other: that is to say, it gives the power of imagination and takes away the ability to profit by it." - Beaudalaire (1860)


Where to from here?

If you would like to make an appointment to see a counsellor to learn more about this topic please contact the counselling service on your campus.  Distance students can contact any one of the campuses.

Please tell the receptionist if you need an urgent appointment.

Albany: Health and Counselling Centre Monday to Friday 8.30 am - 5.00 pm. Telephone (09) 213 6700.

Manawatu: Student Counselling Service, Turitea Campus, Monday to Friday 8.30 am - 5.00 pm (8.30 - 4.30 during semester breaks). Telephone (06) 350-5533.

Wellington: Student Counselling Service, The Student Services Trust @ Wellington, Monday to Friday 8.30 am - 4.30 pm. Telephone (04) 801-2542.

Massey Contact Centre Mon - Fri 8:30am to 5:00pm 0800 MASSEY (+64 6 350 5701) TXT 5222 Web chat Staff Alumni News Māori @ Massey