1. What is cannabis?

Cannabis is extracted from a plant called Cannabis sativa. The active ingredient is known as “THC” (tetrahydrocannabinol), which is present in the flowers, leaves and stalk of the plant. Therefore, cannabis available in illegal market is in the form of dried flowers and leaves (nicknamed as “grass”). Cannabis is usually consumed by smoking as it is made into cigarettes with rolling paper. Many people believe occasional use of cannabis helps relaxation without any harmful effort, it is wrong.

2. What are the effects of cannabis?

The effect of cannabis differs among individuals. Even within the same person, the effect can be different when cannabis is consumed upon different mood states. On one hand, cannabis might cause euphoria and accentuate the perceptual input, e.g. making a song more exciting or colours appear brighter. On the other hand, it might cause adverse psychological reactions, including anxiety, suspiciousness or hallucination. These effects usually last for a few hours, but cannabis could stay in the body a much longer time, for example a few weeks among frequent users.

3. How does cannabis abuse affect our daily live?

Research found that cannabis impairs cognitive functions including concentration and planning, leading to decline of performance in school or at work, e.g. making careless mistakes and being easily distractible. Drivers who use cannabis are prone to fatal road traffic accidents.

4. Will cannabis cause mental disorders?

Repetitive use of cannabis, particular for people in teenage, predisposes a person to a number of mental disorders. The risk is further increased when there is a family history of mental illness. A study in Australia found that among a group of teenagers, those who habitually took cannabis had 5-time higher risk of having depressive or anxiety disorder in adulthood. A few large-scale international studies came to a consistent finding that adolescent use of cannabis increases risk of schizophrenia, a severe mental illness which requires long term treatment.

5. Is cannabis addictive?

Repetitive use of cannabis, particularly daily use, leads to addiction. Once addicted, the person suffers from an intense psychological craving which makes him surrender most of his time and money to cannabis, despite knowing the harm. Tolerance to cannabis develops with time, and the person has to take more and more cannabis to obtain the desired psychological effect. Once the cannabis consumption is disrupted or reduced, withdrawal symptoms, such as insomnia, irritability, restlessness and loss of appetite, can appear within half a day and persist for one to two weeks.