In 2005 the United Nations Office on Drugs and Crime (UNODC) issued its World Drugs Report. This reported that the global drug trade generates more than $320 billion a year in revenues, primarily from retail drug sales. A UN official pointed out that in relative terms that is almost equivalent to 0.9% of the world's Gross Domestic Product or higher than the GDP of 88% of the countries in the world.

Europe alone is estimated to spend $70 billion on drugs whilst in North America that figures approaches $100 billion. And worldwide, the number of people who used an illegal drug at least once last year was 200 million, or 5% of the adult population. These astonishing figures clearly highlight the abundant use of drugs in the modern age.

Although the reasons for this drug use cannot be fully examined here, a very general explanation is that people wish to access altered states. It is these altered states that provide the drug user with his/her desired feeling of relaxation, escapism, inner peace, ecstasy, creativity, sedateness etc. For most people though these feelings and sensations can be accessed through conventional natural highs that arise in the process of everyday life. Or on the other hand people may simply not need drugs to cope with their problems or circumstances.

Yet, there is also a separate category of people who frequent in drugs for a deeper reason. They wish to explore their own 'inner space' beyond what the standard array of natural highs can provide. These people realize that there are many layers to consciousness, most of which we never access.

The famous novelist Aldous Huxley was one such explorer. By meticulously documenting his experiences with mescaline he was able to explore his own mental realms which would also inspire countless others to do so through his book 'The Doors of Perception'. He would be succeeded in his work by other 'mental explorers' such as Timothy Leary and Terrence McKenna who widely experimented with a variety of entheogenic drugs.

Interestingly, when we look back across history we find that the use of entheogens in human culture is widespread. Their use can be traced to many different cultures around the world. The shamans of South America, dating from as far back as the time of the Maya, continue to use the ayahuasca plant for its connection and insight into spiritual realms. In West Africa the Iboga shrub is the method used by indigenous tribes to access dimensions of consciousness altogether unknown to the average human. And in Mexico the native Indians are well known for their frequent ingestion of the Peyote Cactus which contains mescaline. The continued use of these substances suggests they continue to play an important role in many tribal and indigenous societies.