Cannabis

Cannabis

Cannabis is a genus of flowering plants used for medical, recreational, and industrial purposes. The plant contains hundreds of chemical constituents, including cannabinoids such as tetrahydrocannabinol (THC) and cannabidiol (CBD), plus terpenes and flavonoids. The psychoactive effects commonly associated with cannabis are largely driven by THC.

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Uses

  • Medical: Symptom relief (pain, spasticity, nausea), appetite stimulation, some licensed indications for epilepsy (CBD preparations). Evidence strength varies by condition — see linked pages for details.
  • Recreational: Used for relaxation, socialising and altered states of consciousness. Effects depend on dose, route, cannabinoid profile and individual sensitivity.
  • Industrial: Fibre and seed uses come from hemp varieties (low-THC Cannabis sativa cultivars).

Pharmacology

Cannabinoids interact with the body's endocannabinoid system (ECS) — a widespread signalling system that helps regulate appetite, mood, memory, pain and reproductive processes. THC is a partial agonist at CB1 receptors in the brain, producing most psychoactive effects; CBD has a complex pharmacology and does not produce the same intoxicating effects.

Risks & Harms

  • Acute effects: Short-term memory impairment, altered perception of time, impaired coordination, tachycardia, dry mouth, and anxiety or panic at high doses.
  • Mental health: Regular high-potency use is associated with increased risk of psychosis, particularly in adolescents and people with pre-existing vulnerability.
  • Dependence: Cannabis use disorder can develop in a subset of users; risk increases with earlier onset and heavier use.
  • Respiratory harms: Smoking any plant material can irritate the airways; long-term smoked use may increase chronic bronchitis symptoms.
  • Cannabinoid hyperemesis syndrome (CHS): Cyclical vomiting associated with chronic heavy cannabis use in some people.

Pregnancy, breastfeeding & fertility

Cannabis is commonly used among pregnant women in some populations. Evidence links prenatal exposure to potential risks for fetal growth and neurodevelopment; breastfeeding transfers cannabinoids to infants. See Cannabis and pregnancy for a focused summary and sources.

Legal Status & Access

Laws vary widely by country and subnational jurisdiction — from decriminalisation and legal regulated markets to strict prohibition. See Legal status summary.

Writing Tips

  • Tone & accuracy: Use anatomical and pharmacological terms when they add clarity, but avoid unnecessary jargon in narrative scenes.
  • Sensory detail: Mention onset differences between inhalation (minutes) and oral consumption (up to 90 minutes) to create believable pacing.
  • Characterisation: People use cannabis for many reasons — social, medicinal, ceremonial — and motives shape how scenes are written.
  • Avoid stereotypes: Not all cannabis users are stoners; include diversity in age, gender, class and cultural context.

Further reading