Research has shown that persistent cannabis use among teenagers under the age of 18, results in neuropsychological decline which persists even after they have ceased consumption. This study which took more than 30 years in the making indicated that smoking marijuana results in a permanent reduction in intelligence, as measured by the IQ.  The research showed that the neuropsychological effect of persistent cannabis smoking was most damaging if it started before the user was 18 years of age, and much less so if onset began later in life. An eight point reduction in the intelligence quotient was observed in such individuals. Such a slump in the IQ is enough to instigate a significantly negative impact upon their lives.

arman3Mr. Arman Ahmed has completed his MS in Clinical Psychology from Government College University, Lahore. He is also an alumni of Forman Christian College and Aitchison College Lahore. His research work includes experimental studies on concepts of emotion regulation, empathy and threatened  egotism. His interests also extend to topics in the sphere of social psychology such as locus of control and superstitions.

Editor: Mr. Saad Shaheed

The researchers maintain that an ever expanding number of teenagers today have started subscribing to the belief that cannabis intake does not significantly harm health. As a consequence, a decline has also been witnessed in the age at which individuals start using cannabis. In general, as the perception of cannabis being dangerous has declined amongst the youth, its consumption has increased. Recent studies show that today, high school students in America are more likely to smoke marijuana on a daily basis rather than consuming cigarettes. Both heavy and regular cannabis usage has been linked to marked neuropsychological decline across all important domains of functioning notwithstanding the many years of education that a person has received. The problems were found to be significantly greater amongst those who engaged in persistent intake of cannabis. Moreover, it was determined that the neuropsychological deficits persisted even after cannabis consumption was completely ceased.


The study was longitudinal in nature in the respect that researchers followed and tested subjects from birth to age 38, paying specific attention to when and how subjects picked up the habit of drug usage.