The latest study of teenage cannabis addiction, which has been ongoing since 1972 has been published and shows that it can seriously lower IQ levels in young users.
Conducting the survey, Professor Terrie Moffitt of Kings College London, said they had ruled out other influencing factors such as alcohol use, dropping out of school and taking other hard drugs and were sure that the decline in IQ levels was solely due to cannabis use.
Speaking to the BBC she said that prolonged use had effects on the ability to concentrate, speed of mental reactions and problems with memory loss. The results showed that these deficiencies remained with users even after a year or more without using cannabis.
The effects were found to be irreversible in cannabis addicts who had started smoking as teenagers and the professor believed the effects were due to the fact that at this age, teenage brains were still developing. The results followed over 1,000 subjects over a period of 25 years, with tests taken from some when they were very young and not using cannabis, going through to the age of 38 years old.
What the survey showed was that teenagers who were cannabis addicts dropped on average 8 points in the IQ tests. Moffitt said that those taking part were reliable subjects and quite candid with information regarding their drug use and a confidentiality guarantee meant that 96% from the original research in 1972 were still active in the program.
To stop smoking weed in Birmingham, speak to Life Principles.