Health effects

Short-term effects
Greater quantities of cannabis can cause unpleasant effects, including:

• Confusion
• mild hallucinations
• paranoia
• impaired coordination
• restlessness
• depression.

Long-term effects
Long-term cannabis smoking affects both mental and physical health. The mental conditions include:

• memory loss and brain function: The ability to learn and remember is impaired by regular cannabis use. Short-term memory is especially affected
• concentration: Regular users find it harder to concentrate for longer periods of time
• motivation: Regular users find it hard to stay motivated for sport, school and work, and their energy levels suffer. These effects do diminish over time after once cannabis use has ceased.

The smoking of cannabis presents similar health risks to tobacco smoking. Smoke releases carcinogens that can affect the respiratory system, and the risk increases because cannabis smokers tend to inhale more deeply and hold the smoke in longer.

There is also evidence that cannabis affects a person's hormones. Regular users sometimes report a lower sex drive, irregular menstrual cycles for women and lower sperm counts in men.

Currently there is no evidence to suggest that occasional use of small amounts of cannabis causes any permanent damage.