Researchers have found that cannabis may affect decision-making and memory.
Canadian scientists reviewed scientific evidence regarding the drug.
They warned the effects of cannabis — or marijuana — can persist well beyond the period of intoxication.
University of Montreal researchers claimed that students who have smoked the drug might be more successful at school.
Adults who take the drug (class B in Britain) could have problems at work and impaired driving abilities.
Cannabis makes people worse at reacting quickly, making decisions and learning from reading and listening months after, a study by University of Montreal researchers claimed today
The review, published in the journal Addiction, concluded the impairments ‘may be worse in regular and heavy users’.
Research has shown that more prevention strategies are required in schools to keep adolescents away from the drug’s use.
Montreal researchers analysed cannabis research that involved more than 43,000 individuals.
Each study paper examined how drug affects memory, learning, attention and processing speed.
The effects of cannabis on cognitive performance were assessed in two ways: immediately following the intake and over the long-term.
These studies included experiments that involved as little as 65 volunteers to those that were large enough for thousands.
And they involved a range of smoking habits — from daily use to abstinence.
It was discovered that heavy and regular use can hinder decision-making and flexibility, as well as self-control.
Another study suggested that regular use of cannabis could hinder people’s ability to manage their behavior and make them less capable of making ‘appropriate choices’.
Research also showed adults given THC — the psychoactive substance that gives off a ‘high’ — performed worse in memory tests.
Not all the studies were in agreement. However, some analyses showed no effects on memory from regular cannabis consumption.
Alexandre Dumais, psychiatrist and coauthor of the study, stated that marijuana can affect’several aspects of cognition.
These include ‘problems concentrating and difficulties remembering and learning, which may have considerable impact on users’ daily lives’.
According to him, “Cannabis usage in youth can consequently lead to lower educational attainment, as well as to poor work performance, dangerous driving and reduced education,”
These consequences can be even worse for regular or heavy users.
Previous studies have shown the drug — which is used medicinally across the world — can alleviate depression, anxiety and stress.
Heavy use can make depression worse over time because it reduces the brain’s ability of letting go of negative memories.
According to studies, it may also lead to mental illness in people with existing conditions, as well as increase risk of schizophrenia and psychosis.
In more than half the US, marijuana can be used for medical purposes. It is commonly prescribed to treat anxiety, aggression, and sleep problems. It is also being investigated by researchers if it might help those with autism, eczema and psoriasis.