Cannabis, like other psychoactive substances such as alcohol, tobacco and opiates, is used for a variety of reasons. For some users it is simply the pleasure of an altered state and a social experience. For others, it is a way of coping with the troubles of everyday life, a source of solace or, indeed, a source of cognitive benefits and enhanced creativity (Iversen, 2008). For yet other users it has a therapeutic value for some physical or mental health problem. Though the medical value of cannabis is not well researched, it is plausible that it does in fact provide relief for a number of conditions, such as AIDS wasting syndrome or glaucoma (Institute of Medicine, 1999).
Cannabis first became popular in the West in the 1960s, when its use emerged as part of the general youth rebellion of that decade. From North America it spread, over the next twenty years, to most of Western Europe, as well as to Australia. After the collapse of the Soviet Union, it also spread in the 1990s to many countries in Eastern Europe. There is, however, substantial variation in rates of use across these nations: Finland and Sweden, for example, have rates of users on a lifetime basis that are about two-fifths the rate in Great Britain (EMCDDA, 2007: Table GPS-8). In the countries with high rates of cannabis use, roughly half of all adults born since 1960 have used the drug.
Cannabis is now used in every region of the world. The percentage of adults who report use in the past year was higher than the global average in Oceania (16%), North America (11%), Africa (8%) and Western Europe (7%). It was at or below the global average in Eastern Europe (4%), South America (2%), South-East Europe (2%) and Asia (2%) (UNODC, 2007). Because of their larger populations, Asia and Africa accounted for 31% and 24% of global cannabis use respectively, followed by the Americas (24%), Europe (19%) and Oceania (2%).
The United States and Australia have conducted surveys of drug use since the mid-1970s and mid-1980s respectively (AIHW, 2007; SAMHSA, 2006). In the United States in 2005, 40% of the adult population reported trying cannabis at some time in their lives, with 13% of adolescents reporting use in the past year (SAMHSA,
2006). In Australia in 2007, 34% of persons over the age of 15 reported that they had used cannabis at some time in their lives (AIHW, 2008).
Rates are highest among youth, particularly young adults, and use tails off slowly in the mid-30s. At the other end of the age of use spectrum, the age of first use has fallen since about 2000 in some countries, but not others (Hibell et al., 2004; Degenhardt et al., 2000).
Cannabis use in the USA typically begins in the mid to late teens, and is most prevalent in the early 20s (Bachman et al., 1997). Most cannabis use is intermittent and time-limited, with very few users engaging in daily cannabis use over a period of years (Bachman et al., 1997). In the USA and Australia, about 10% of those who ever use cannabis become daily users, and another 20% to 30% use weekly (Hall & Pacula, 2003). Cannabis use declines from the early and mid-20s to the early 30s, reflecting major role transitions in early adulthood (e.g. entering tertiary education, entering fulltime employment, marrying, and having children) (Anthony, 2006; Bachman et al., 1997). The largest decreases are seen in cannabis use among males and females after marriage, and especially after childbirth (Bachman et al., 1997; Chen & Kandel, 1995).
While marijuana use, once it is established in a society, seems never to fall to very low rates, there has been substantial variation in prevalence over the last decades. For example, whereas in 1979 50.8 percent of American high school seniors had used marijuana in the previous twelve months, by 1992 that figure had fallen to 21.9 percent; it then rose again to 37.8 percent in 1999 (Johnston et al. 2007). Interestingly, there seems to be a common pattern over time across countries. For most western nations between 1991 and 1998 there was an increase of about half in the proportion of 18 year olds reporting that they had tried cannabis. Since 1998 in the same countries there has been a substantial decline in that figure, though in 2006 it still remains well above the 1991 level.
The common patterns across countries with very different policy approaches reinforce the general impression that penalties for personal use have very little impact on the prevalence of cannabis use in a society. What does explain the changes remains essentially a mystery, but popular youth culture, including representation of the drug in music, films and magazines, probably plays an important role. The linked patterns of fluctuation in use in different countries suggest the influence across borders of a global youth popular culture.
Marijuana use can be thought of as a "career". Most users try the drug a few times, and are at very low risk of suffering or causing any substantial harm. However recent research has confirmed that a substantial fraction will use the drug regularly over the course of ten or more years, and that perhaps 10 percent of those trying cannabis at some stage will become dependent upon it. Among those who begin to use in their early teens, the risk of developing problem use may be as high as one in six (Anthony, 2006). It is worth comparing the drug's use in these respects to alcohol and tobacco on the one hand, and to cocaine and heroin on the other. Cannabis is most like alcohol, in that most users do not become dependent but many do have using careers that stretch over years, although in current circumstances not for as long as for alcohol.
Was this article helpful?