Crystal meth, cocaine and heroin have a reputation for their high addictive qualities. But a recent study conducted by Cambridge University Press contends that another drug is overlooked. According to certain medical researchers, marijuana, cannabis or ganja is another habit-forming substance.

For more than two decades, American researchers have been studying the effects of habitual marijuana use. While many users counter the addictive powers of the naturally grown herb, a new book, titled, "Cannabis Dependence" documents the effects of habitual marijuana usage.

The federally funded study and book provide scientific evidence on marijuana’s euphoric powers from its primary ingredient, THC. The findings published in the book show between two and three percent of marijuana users are addicted within the first two years of use. Also, the book notes that 10 percent of America’s regular ganja users become addicted at some point in their life.

Today, the statistics for treating marijuana use are growing dramatically. As the number of cases of alcohol addiction plummeted from 57 percent to 41 percent, the number of reported marijuana addictions soared from seven to 16 percent.

Researchers placed advertisements in newspapers across the country to conduct the study. The ads offered complimentary treatment for individuals in need of help to kick their addiction. Average participants were Caucasian males in their thirties. Compared with the regular drinkers, the average addiction rate of perpetual marijuana users was higher. Unlike the side events of other addictive substances, marijuana addiction is not related to deaths, a ruined career, or other life altering ramifications.

Although the researchers were unable to draw conclusive health effects of habitual use of marijuana, symptom of marijuana withdrawal showed the following adverse events: irritability, anger, sleep disturbances and nervousness.