Could cannabis use in young people permanently affect their IQ?

A report this week concludes that young people who smoke cannabis for years run the risk of a significant and irreversible reduction in their IQ. The study, conducted by an international group of researchers. Was based on findings from a sample of 1000 people in New Zealand. It found that those who used cannabis below the age of 18 years old – when their brains were not fully developed – suffered a permanent loss in their IQ. There would appear to be a correlation between this and under achievement more generally amongst cannabis users.

The research took place over a period of more than 20 years in Dunedin in New Zealand.

The researchers conducted a longitudinal study, assessing the individuals as children – before any of them had started using cannabis – and then re-interviewing them repeatedly, up to the age of 38. After controlling for other factors such as alcohol or tobacco dependency as well as other drug use. Taking into account the number of years spent in education, they found that those who persistently used cannabis – smoking it at least four times a week year after year through their teens, 20’s and, in some cases, their 30’s – suffered a decline in their IQ. There was also a correlation between the amount smoked and the extent of the loss in IQ.

However, there was not the same effect on those who started smoking cannabis over the age of 18, once their brains were fully developed.

So does this mean that cannabis is safe to use, so long as only adults use it?

Cannabis is viewed as a relatively harmless drug by many. It is a gateway drug and in many users it leads to them taking other ‘more harmful’ drugs. Its use can initially lead people to feel relaxed, with a general sense of well being or even euphoria. It can lead to increased appetite, and can make users view things a ‘funny’ leading to a fit of the giggles, for example. It can enhance the user’s natural mood, leading to happy people feeling happier, and those feeling down to feeling more depressed. Physically it can lead to a dry mouth and bloodshot eyes. As well as an increased heart rate but lower blood pressure. It can lead to a feeling of grogginess and memory loss. It can lead to lower fertility in both men and women and miscarriage.

Long term use

Long term use can lead to people being dull, inattentive and paranoid. It can therefore harm their ability to maintain relationships and keep friends. All this seems a high price to pay for what initially offered a little relaxation. There are many more ways to relax and feel good in a social setting than smoking (or eating) cannabis!

Addiction to cannabis is also a real risk.

The Haynes Clinic is a drug and alcohol rehab clinic which treats all forms of addiction including cannabis. The clinic is a total abstinence clinic, following the Twelve Step Programme (originally of AA). The clinic’s philosophy is that cannabis use is harmful in itself and also often leads to use of harder drugs.

Call us on 01462 851414 

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