Marijuana is the most widely used illicit drug in the United States and tends to be the first illegal drug teens use.  However, this is not to say that the majority of teens use marijuana.  In fact, according to a survey of high school seniors, while 30.7% used marijuana sometime within the past year, 69.3% did not use marijuana.  Additionally, most marijuana users do not go on to use other illegal drugs.

Marijuana has several negative physical and mental effects.  Use of marijuana may impair or reduce short-term memory and comprehension, alter sense of time, and reduce ability to perform tasks requiring concentration and coordination, such as driving a car.

• Sleepiness and increased hunger

• Difficulty keeping track of time, impaired or reduced short-term memory

• Reduced ability to perform tasks requiring concentration and coordination, such as driving a car

• Increased heart rate

• Potential cardiac dangers for those with preexisting heart disease

• Bloodshot eyes

• Decreased social inhibitions

• Risk of paranoia, hallucination, intense anxiety

• Increased risk of chronic pulmonary disorders, including cancer

• Decrease in testosterone levels for men

• Increase in testosterone levels for women

• Lower sperm counts and difficulty having children in men

• Increased risk of infertility in women

• Diminished or extinguished sexual pleasure

• Psychological dependence requiring more of the drug to get the same effect