What are the adverse effects of cannabis?
Adverse effects are physical, psychosocial and psychiatric. Cannabis is usually smoked, so users are exposed to the hazards of smoking as well as the 400-plus chemicals found in cannabis. Three of the 60 or so compounds it contains bind to cannabinoid receptors in brain areas linked to pleasure, memory, thought and concentration. This can affect users’ work, education and driving skills, and may particularly harm the developing brain. THC (delta-9-tetrahydrocannibol) can depress frontal lobe inhibition of inappropriate thoughts and behaviour and is responsible for the ‘high’. Users may be less vigilant about avoiding hazards such as unprotected sex and risks to personal safety. Cannabis today is much stronger than in the 1960s and can trigger depression, anxiety or psychotic disorders such as schizophrenia, especially where there is a family background of mental illness. Around one in 10 users may have unpleasant experiences including confusion, anxiety, hallucinations and paranoia. A
