Those who push for the legalisation of cannabis tend to cite studies that point to the cannabinoids found in cannabis that have potential use for some medical treatments (Two suspects arrested for growing cannabis plants, Sept 11).
Cannabinoids operate in a similar way to molecules produced by the human body known as endocannabinoids.
Both plant and human versions of the molecules can activate a wide network of receptors in the human brain and body to generate different reactions. These reactions can affect memory, mood, sleep, appetite, stress and pain.
Some clinical studies have supported the efficacy of some cannabinoids in the treatment of a range of conditions, including nausea induced by chemotherapy, muscle pain in multiple sclerosis, chronic pain in adults, and treatment-resistant epilepsy.
Having said that, consuming cannabis can have physical, emotional and mental effects, otherwise known as getting "high" or "stoned".
Over time and if taken indiscriminately, it can become addictive and lead to impairment of attention, mental ability and memory, as well as increased risk of accidents.
In addition, it can cause physical, mental, behavioural and social health consequences, including affecting the health of the liver, lungs and heart.
If medical cannabis is legalised, it may open the door for its recreational use.
For example, when an athlete starts to smoke cannabis to relieve pain from sports injury, cannabis will become a part of our communities and society.
Ease of access will make it likely for abuse and it may lead to other social problems, including increase in crimes to support the purchase of cannabis.
In a bigger picture, initiatives to legalise cannabis for both medical and recreational use can cause the breakdown of international drug treaties, which in turn will affect international law.
Singapore should continue to adopt a strong stand against cannabis. To change our position, we need to prove beyond a shadow of doubt the benefits of consuming cannabis, if any, and to develop ways to eradicate resulting risks and downsides of legalising cannabis.
Patrick Liew Siow Gian (Dr)
