Myth: Marijuana is harmless.

Marijuana contains cancer causing substances and produces dependence (addiction). In fact, most youth who have to enter drug treatment are dependent on marijuana. Newer, more potent varieties cause more profound effects. Acutely, marijuana use can cause anxiety, dysphoria, panic and hallucinations, especially in new users. Chronic marijuana smokers are more susceptible to diseases like upper respiratory infections, emphysema, and chronic bronchitis. Chronic marijuana users experience problems with attention span and memory. Also, marijuana clearly causes psychomotor impairment, making driving cars or operating any heavy machinery dangerous while under the influence.