Effects of cannabis

Using cannabis disrupts the central nervous system, affecting how people who use it function and what they can do. It can cause risks and have adverse effects on your health. Cannabis is not harmless, and it is not just something else that is out there.

The main attraction of non-medical cannabis use is the high—a kind of euphoria—mainly caused by the THC. Occasional users tend to experience the main effects in two successive phases.

The first phase, the “high”, occurs a few minutes after the person has smoked, vaporized, or vaped cannabis (inhalation) or an hour after eating or drinking it (ingestion). The effects are:

• Euphoria, sense of satisfaction
• Carefree mood
• Increased sociability
• Heightened experience of the senses
• Impression of being more creative
• Spontaneous laughter

The second phase, the “down”, usually occurs an hour or more after inhalation or six hours or more after ingestion. The effects are:

• Lethargy, slowed physical and mental functioning, caused by the elimination of THC from the body

Cognitive function may be affected in both phases—high and stoned. Cognitive functions are those that depend on the brain, allowing us to communicate, perceive our surroundings, concentrate, remember, and learn. A person under the influence of cannabis might therefore experience the following:

• Disruption of:
  • Short- and medium-term memory
  • Attentiveness
  • Concentration
• Impaired judgement
• Slower reaction time

Inhalation of cannabis smoke or vapour affects cognitive abilities very rapidly. The effect peaks in roughly 30 minutes and generally takes less than six hours to fade. When cannabis is consumed in edible forms, the effect takes longer to appear (between 30 and 60 minutes) and lasts longer (up to eight hours).

The experience of using a drug is influenced by many factors—the user’s physiology and mood, the substance used, and the context they use it in. These things combine together into associations that are subject to the law of effect.

The effects of cannabis vary enormously from one user to the next, in response to external parameters such as:

• The form used (e.g., dried cannabis, hashish, dabs)
• The dose taken
• The concentrations of THC and CBD in the preparation used
• The method of consumption (i.e., inhalation or ingestion)
• The user’s experience
• The frequency of use
• The user’s physical and mental state
• Social context (e.g., alone at home, with others at a party)
• Alcohol, other drugs, or medications used with cannabis, which can amplify the effects