The self-medication hypothesis was not supported in either the van Os or Henquet studies. Both studies found that early psychotic symptoms did not predict an increased risk of using cannabis (as is required by the self-medication hypothesis). The direction of the relationships was from early cannabis use to psychosis. Their negative results have recently been supported by Verdoux et al. (2002), who examined the temporal relationship between cannabis use and psychotic symptoms using an experience sampling method. They asked 79 college students to report on their drug use and experience of psychotic symptoms at randomly selected time points, several times each day over 7 consecutive days. The sample included high cannabis users (n = 41) and an over-representation of students identified as vulnerable to psychosis (n = 16). Verdoux and colleagues found that in time periods when cannabis was used, users reported more unusual perceptions, and these relationships were stronger in vulnerable individuals. There was no temporal relationship between reporting unusual experiences and using cannabis use, as would be predicted by the self-medication hypothesis.
In some areas where cannabis use had been historically tolerated, new restrictions were instituted, such as the closing of cannabis coffee shops near the borders of the Netherlands, and closing of coffee shops near secondary schools in the Netherlands. In Copenhagen, Denmark in 2014, mayor Frank Jensen discussed possibilities for the city to legalize cannabis production and commerce.
Last year, the Hemp Industries Association (HIA) estimated the total retail value of all hemp products sold in the U.S. at $620 million. Sadly, all of the raw hemp materials were imported from other countries. (More on that later.) Hemp is an attractive rotation crop for farmers. As it grows, hemp breathes in CO2, detoxifies the soil, and prevents soil erosion. What’s left after harvest breaks down into the soil, providing valuable nutrients.
Recent European Commission proposals to change its subsidy regime for hemp contained the following negative evaluation of hemp seed: “The use of hemp seed ... would, however, even in the absence of THC, contribute towards making the narcotic use of cannabis acceptable... In this light, subsidy will be denied producers who are growing grain for use in human nutrition and cosmetics.”
More recently, Sakamoto and various co-authors have used RAPD to isolate several genetic marker sequences that they name Male-Associated DNA in Cannabis (MADC), and which they interpret as indirect evidence of a male chromosome. Several other research groups have reported identification of male-associated markers using RAPD and AFLP. Ainsworth commented on these findings, stating,
Those warning letters aside, there’s not a lot of federal oversight right now over the claims being made or the products that are being sold. Cohen warned against buying CBD products online, because “there’s a lot of scams out there.” Yet his clinic sells CBD, and he admits, “I say ‘Don’t buy online,’ but ours is worth doing, because we know what we’re doing. We ship all over.”
It is not surprising that male-associated markers are relatively abundant. In dioecious plants where sex chromosomes have not been identified, markers for maleness indicate either the presence of sex chromosomes which have not been distinguished by cytological methods or that the marker is tightly linked to a gene involved in sex determination.
George Washington also imported the Indian Hemp plant from Asia, which was used for fiber and, by some growers, for intoxicating resin production. In a letter to William Pearce who managed the plants for him Washington says, "What was done with the Indian Hemp plant from last summer? It ought, all of it, to be sown again; that not only a stock of seed sufficient for my own purposes might have been raised, but to have disseminated seed to others; as it is more valuable than common hemp."
A recent study published in The International Journal of Neurophamacologypoints to cannabidiol (CBD) as a cause of neurogenesis in the brain; specifically in the Hippocampus, an area typically associated with conscious memory and navigation. However, the researchers believe that CBD’s anxiety relief may be due to this neurogenesis in the brain. You can read our full article on the study here.
Industrial hemp is from the plant species Cannabis sativa and has been used worldwide to produce a variety of industrial and consumer products. Hemp is a source of fiber and oilseed grown in more than 30 nations. In the United States production is controlled under drug enforcement laws. To produce industrial hemp in the United States the grower must obtain a permit from the Drug Enforcement Agency (DEA).
Cannabis has been cultivated for millennia, but has been largely absent from scientific research during the past century. The herb is undergoing a resurgence of botanical and biomedical interest, spurred by claims of its therapeutic benefits. Yet research into these claims lags behind the legislation that allows medical marijuana use. Scientists are racing to fill this cannabis knowledge gap.
The plant was first given its taxonomic identification by Carl Linnaeus in 1753 and thoroughly described to Westerners in the 1800s, when the medical doctor William O'Shaughnessy gave a report to the Medical and Physical Society of Calcutta in India in 1839. The doctor described its effects on people and did a few case reports on "gunjah," the Indian name for the drug.
Hemp is used to make a variety of commercial and industrial products including rope, textiles, clothing, shoes, food, paper, bioplastics, insulation, and biofuel. The bast fibers can be used to make textiles that are 100% hemp, but they are commonly blended with other fibers, such as flax, cotton or silk, as well as virgin and recycled polyester, to make woven fabrics for apparel and furnishings. The inner two fibers of the plant are more woody and typically have industrial applications, such as mulch, animal bedding and litter. When oxidized (often erroneously referred to as "drying"), hemp oil from the seeds becomes solid and can be used in the manufacture of oil-based paints, in creams as a moisturizing agent, for cooking, and in plastics. Hemp seeds have been used in bird feed mix as well. A survey in 2003 showed that more than 95% of hemp seed sold in the European Union was used in animal and bird feed.
Hemp is possibly one of the earliest plants to be cultivated. An archeological site in the Oki Islands near Japan contained cannabis achenes from about 8000 BC, probably signifying use of the plant. Hemp use archaeologically dates back to the Neolithic Age in China, with hemp fiber imprints found on Yangshao culture pottery dating from the 5th millennium BC. The Chinese later used hemp to make clothes, shoes, ropes, and an early form of paper. The classical Greek historian Herodotus (ca. 480 BC) reported that the inhabitants of Scythia would often inhale the vapors of hemp-seed smoke, both as ritual and for their own pleasurable recreation.