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Marijuana

THC Hampers Spatial Memory Development in Young Monkeys

Adolescent monkeys that were exposed to THC fell progressively further behind THC-free monkeys in their ability to recall the location of an object after a brief delay.

Among High School Seniors, Driving After Marijuana Use Surpasses Drunk Driving

Within the 2 weeks prior to responding to a nationwide survey, 28 percent of high school seniors were in a vehicle whose driver had been using marijuana or another illicit drug, or had drunk 5 or more alcoholic drinks.

Device Detects Marijuana in Breath Hours After Smoking

Driving under the influence of marijuana is a dangerous public health concern. NIDA researchers have discovered that breath expelled into a Breathalyzer-style collection device contained measurable amounts of THC for up to 2 hours after participants in a recent clinical trial smoked the drug.

Marijuana Use May Promote Nicotine Consumption

Exposing rats to THC increases the likelihood that the animals will later self-administer nicotine. THC-exposed rats are also willing to work harder to obtain nicotine. When extrapolated to people, the findings suggest that THC’s pharmacological impact on the brain may make a person who uses marijuana more vulnerable to developing nicotine addiction, an underappreciated health consequence of marijuana use.

In Nationwide Survey, More Students Use Marijuana, Fewer Use Other Drugs

Almost one-third (32 percent) of the roughly 42,000 Monitoring the Future survey respondents reported having used marijuana during their lifetime. However, abuse of many other drugs—methamphetamine, heroin, cocaine, and some prescription medications—declined.

Study Parses Comorbidity of Cannabis Use and Social Anxiety

People with cannabis use disorder (CUD) are likely also to have social anxiety disorder (SAD), and comorbid SAD is associated with greater severity of cannabis-related problems. These findings highlight the importance of assessing CUD patients for SAD, as that disorder can be both a contributing cause and a consequence of CUD. Treating both disorders may be a key to helping patients recover from each.

Early-Onset, Regular Cannabis Use Is Linked to IQ Decline

Regular cannabis use that starts in adolescence strips away IQ, a NIDA-supported study suggests. Participants who initiated weekly cannabis use before age 18 dropped IQ points in proportion to how long they persisted in using the drug. Persistent cannabis users’ cognitive difficulties were evident to friends and family and measurable on a battery of tests.

Is Marijuana Medicine?

What is medical marijuana?

Photo of a person's fingers holding up a marijuana leaf.

The term medical marijuana refers to using the whole unprocessed marijuana plant or its basic extracts to treat a disease or symptom. The U.S. Food and Drug Administration (FDA) has not recognized or approved the marijuana plant as medicine.

Marijuana

Explores the latest research on marijuana, including the scope of marijuana use in the U.S., health consequences, its effects on everyday activities, and available treatments.

Published: October 2002
Revised: September 2015

Marijuana: Facts for Teens

Presented in question-and-answer format and targeted to teens, provides facts about marijuana and its potential harmful effects.

Published: April 2001
Revised: May 2015

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