When to see a doctor. See a doctor if you or a loved one has memory problems or other dementia symptoms. Some treatable medical conditions can cause dementia symptoms, so it's important to determine the underlying cause.
A brief history of tobacco. (CNN) -- Tobacco was first used by the peoples of the pre-Columbian Americas. Native Americans apparently cultivated the plant and smoked it in pipes for medicinal and ceremonial purposes.
The Origins of Cannabis. The oldest known written record on cannabis use comes from the Chinese Emperor Shen Nung in 2727 B.C. Ancient Greeks and Romans were also familiar with cannabis, while in the Middle East, use spread throughout the Islamic empire to North Africa. In 1545 cannabis spread to the western hemisphere where Spaniards imported it to Chile for its use as fiber. In North America cannabis, in the form of hemp, was grown on many plantations for use in rope, clothing and paper. The Use of Cannabis. Cannabis sativa grows wild throughout many tropical and humid parts of the world.