Marijuana getting more potent than it used to be

London: Smoking pot isn't the same today as it was 20 years ago, according to a new study that suggests marijuana potency is on the rise.

The study analysed nearly 39,000 samples of cannabis seized by the US Drug Enforcement Administration between 1995 and 2014 and found that the levels of the component responsible for marijuana's psychedelic effects, called tetrahydrocannabinol or THC, consistently increased during that time, the Daily Mail reported.

THC levels in the confiscated weed grew from four per cent in 1995 to 12 per cent in 2014 and according to the University of Mississippi researchers, this increase in potency poses higher risk of cannabis use, particularly among adolescents.

However, in contrast, the cannabidiol (CBD) content in those samples decreased from nearly 0.28 per cent in 1995 to less than 0.15 per cent in 2014.

The research noted that the importance of monitoring the potency of confiscated cannabis preparations, used as a measure of what is actually being used by the public, lies in the perceived negative health consequences of the use of the more potent products.

The study noted that emergency department visits involving marijuana have increased over time, corresponding to the increased potency of the drug. Marijuana-related emergency department visits have increased in males by 53.6 per cent and females by 42.9 per cent from 2005 to 2010.

The study is published in the journal Biological Psychiatry.