Porn is addictive for the same reason that many drugs are addictive. Neuroscientist Dr. William Struthers explains how the brain reacts to viewing pornography repeatedly.

Marijuana does not cause overdose deaths and comes with far fewer long-term health consequences. A 2009 Canadian study determined the annual health-related costs associated with alcohol are more than eight times greater per user than with marijuana.

From drugs bans to Wimbledon champions - how did we get here? For the first time in Wimbledon history, both the men's and women's champions have served suspensions for banned substances.

In 1925, H. L. Mencken wrote an impassioned plea: "Prohibition has not only failed in its promises but actually created additional serious and disturbing social problems throughout society. There is not less drunkenness in the Republic but more.

NIDA's mission is to lead the nation in bringing the power of science to bear on drug abuse and addiction. NIDA is part of the National Institutes of Health (NIH) , a component of the U.S. Department of Health and Human Services.