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Adolescent Marijuana Use Linked to Cognitive Problems in Adulthood


Cognitive Problems

Cognitive problems seen in adults who abused marijuana as an adolescent include difficulty making decisions, poor executive function (abstract thinking and planning as well as poor decision-making skills.)

Marijuana Abuse Before the Age of 16

These individuals scored extremely badly on the cognitive testing. They abused marijuana for a longer period of time and smoked more than their older counterparts.

Marijuana Abuse After the Age of 16

This group of individuals scored below average to average on the cognitive testing. The results still indicated that marijuana abuse as an adolescent played a role in their cognitive skills in adulthood.


By the time these individuals started college they already had impaired skills, which caused them to do poorer in college than those who did not abuse marijuana. The study indicated that the primary abusers in this case were males.