Kid Cannabis Use Lowers IQ Permanently
A 20-year study revealed that “persistent cannabis use over 20 y(ears) was associated with neuropsychological decline (IQ decline), and greater decline was evident for more persistent users. This effect was concentrated among adolescent-onset cannabis users, a finding consistent with results of several studies showing executive functioning or verbal IQ deficits among adolescent-onset but not adult-onset chronic cannabis users as well as studies showing impairment of learning, memory, and executive functions in samples of adolescent cannabis users.”
The study further showed:
- “that the impairment was global and detectable across five domains of neuropsychological functioning;
- “that cannabis-associated neuropsychological decline did not occur solely because cannabis users completed fewer years of education
- “that impairment was apparent to third-party informants and that persistent cannabis use interfered with everyday cognitive functioning
- “that among adolescent-onset former persistent cannabis users, impairment was still evident after cessation of use for 1 y or more.
- “these findings are consistent with speculation that cannabis use in adolescence, when the brain is undergoing critical development, may have neurotoxic effects.
This study sends a clear warning that using marijuana, like all drugs, is not without negative side effects. Permanent loss of IQ is just one. Others include increased risk of non-affective psychosis, delusions, hallucinations and depression.