Claiming that it does not endorse attempts to legalise cannabis in any form, the Sri Lanka College of Psychiatrists (SLCP) stated that meticulous research should be undertaken by experts in the field before undertaking such legalisation.

In a statement signed by its President Dr. Sajeewana Amarasinghe, the SLCP stated that several evidence-based implications may occur in the event cannabis is legalised, including de-stigmatisation and normalising of the use of cannabis among the population; the increased potential for adult dependence on cannabis; adverse effects on youth cognitive functions including attention, memory, processing speed, visuo-spatial functioning, and overall intelligence; the risk of developing mental illnesses in vulnerable individuals; the worsening of symptoms of mental illnesses and functional outcomes of those with mental illnesses; cannabis being used as a gateway substance to many other psychoactive substances such as cocaine, methamphetamine, and heroin; and adverse effects on young females of reproductive age.

Further noting that the treatment gap for mental illnesses in some parts of the country is around 67% at present, the SLCP warned that the mental health services of the country would not be able to cope with the increase in disease burden which is likely to occur with any form of legalisation of cannabis.

"There is a lack of scientific evidence to suggest that cannabis is in any way beneficial in the treatment of any psychiatric disorder. However, available evidence supports that there is a strong association between cannabis use and onset of severe psychiatric disorders such as schizophrenia. Cannabis use is also associated with the causation and maintenance of symptoms of a range of psychiatric illnesses." 

The SLCP added that there is scientific evidence to suggest that individuals who use cannabis regularly, or who begin using cannabis early in their lives, are at increased risk of a range of adverse psychosocial outcomes, such as lower levels of educational attainment, poverty, unemployment, increased dependence on the State for welfare, and using other illicit drugs.

Considering the evidence for the increase in disease morbidity and economic burden, it stated that the cost effectiveness of any form of legalisation of cannabis should be meticulously researched. "We don’t endorse attempts to legalise cannabis in any form, and meticulous research should be undertaken by experts in the field before undertaking such legalisation."