Fact Sheet on Effects of Marijuana on the Body
MEMORY/PERCEPTION/BEHAVIOR
1. Attention, memory and learning are impaired among heavy marijuana users, even after users discontinued its use for at least 24 hours. Heavy marijuana use is associated with residual neuropsychological effects even after a day of supervised abstinence from the drug. Heavy users displayed significantly greater impairment than light users on attention/executive functions, as evidenced particularly by greater preservations on card sorting and reduced learning of word lists. These differences remained after controlling for potential confounding variables, such as estimated levels of premorbid cognitive functioning, and for use of alcohol and other substances in the two groups. However, the question remains open as to whether this impairment is due to a residue of drug in the brain, a withdrawal effect from the drug, or a frank neurotoxic effect of the drug. ("The Residual Cognitive Effects of Heavy Marijuana Use in College Students," Pope, HG Jr., Yurgelun-Todd, D., Biological Psychiatry Laboratory, McLean Hospital, Belmont, MA, JAMA February 21, 1996.)
2. Impaired memory for recent events, difficulty concentrating, dreamlike states, impaired motor coordination, impaired driving and other psychomotor skills, slowed reaction time, impaired goal-directed mental activity, and altered peripheral vision are common associated effects. (Adams and Martin 1996; Fehr and Kalant 1983; Hollister 1988a; Institute of Medicine 1982; Tart 1971)
3. A roadside study of reckless drivers who were not impaired by alcohol, showed that 45% of these drivers tested positive for marijuana. (Dr. Dan Brookoff, published in the New England Journal of Medicine)
4. Marijuana smoking affects the brain and leads to impaired short-term memory, perception, judgment and motor skills. (Marijuana Facts: Parents Need to Know, National Institute on Drug Abuse )
5. In a survey of 150 marijuana using students, 59% surveyed report they sometimes forget what a
1. Attention, memory and learning are impaired among heavy marijuana users, even after users discontinued its use for at least 24 hours. Heavy marijuana use is associated with residual neuropsychological effects even after a day of supervised abstinence from the drug. Heavy users displayed significantly greater impairment than light users on attention/executive functions, as evidenced particularly by greater preservations on card sorting and reduced learning of word lists. These differences remained after controlling for potential confounding variables, such as estimated levels of premorbid cognitive functioning, and for use of alcohol and other substances in the two groups. However, the question remains open as to whether this impairment is due to a residue of drug in the brain, a withdrawal effect from the drug, or a frank neurotoxic effect of the drug. ("The Residual Cognitive Effects of Heavy Marijuana Use in College Students," Pope, HG Jr., Yurgelun-Todd, D., Biological Psychiatry Laboratory, McLean Hospital, Belmont, MA, JAMA February 21, 1996.)
2. Impaired memory for recent events, difficulty concentrating, dreamlike states, impaired motor coordination, impaired driving and other psychomotor skills, slowed reaction time, impaired goal-directed mental activity, and altered peripheral vision are common associated effects. (Adams and Martin 1996; Fehr and Kalant 1983; Hollister 1988a; Institute of Medicine 1982; Tart 1971)
3. A roadside study of reckless drivers who were not impaired by alcohol, showed that 45% of these drivers tested positive for marijuana. (Dr. Dan Brookoff, published in the New England Journal of Medicine)
4. Marijuana smoking affects the brain and leads to impaired short-term memory, perception, judgment and motor skills. (Marijuana Facts: Parents Need to Know, National Institute on Drug Abuse )
5. In a survey of 150 marijuana using students, 59% surveyed report they sometimes forget what a