Schizophrenia. Research on the use of cannabidiol for psychotic symptoms in people with schizophrenia is mixed. Some early research suggests that taking cannabidiol four times daily for 4 weeks improves psychotic symptoms and might be as effective as the antipsychotic medication amisulpride. But other early research suggests that taking cannabidiol for 14 days is not beneficial. The mixed results might be related to the cannabidiol dose used and duration of treatment.
About half of the world market for hemp oil is currently used for food and food supplements (de Guzman 2001). For edible purposes, hempseed oil is extracted by cold pressing. Quality is improved by using only the first pressing, and minimizing the number of green seeds present. The oil varies in color from off-yellow to dark green. The taste is pleasantly nutty, sometimes with a touch of bitterness. Hemp oil is high in unsaturated fatty acids (of the order of 75%), which can easily oxidize, so it is unsuitable for frying or baking. The high degree of unsaturation is responsible for the extreme sensitivity to oxidative rancidity. The oil has a relatively short shelf life. It should be extracted under nitrogen (to prevent oxidation), protected from light by being kept in dark bottles, and from heat by refrigeration. Addition of anti-oxidants prolongs the longevity of the oil. Steam sterilization of the seeds, often required by law, allows air to penetrate and so stimulates rancidity. Accordingly, sterilized or roasted hemp seeds, and products made from hemp seed that have been subjected to cooking, should be fresh. The value of hemp oil from the point of view of the primary components is discussed below. In addition, it has been suggested that other components, including trace amounts of terpenes and cannabinoids, could have health benefits (Leizer et al. 2000). According to an ancient legend (Abel 1980), Buddha, the founder of Buddhism, survived a 6-year interval of asceticism by eating nothing but one hemp seed daily. This apocryphal story holds a germ of truth—hemp seed is astonishingly nutritional.
The woody core (hurds, sometimes called shives) of hemp makes remarkably good animal bedding (Fig. 28, 29). The hurds are sometimes molded into small pellets for bedding applications (Fig. 30). Such appears to be unsurpassed for horse bedding, and also make an excellent litter for cats and other pets (Fig. 31). The hurds can absorb up to five times their weight in moisture (typically 50% higher than wood shavings), do not produce dust (following initial dust removal), and are easily composted. Hemp bedding is especially suited to horses allergic to straw. In Europe, the animal bedding market is not considered important (Karus et al. 2000), but in North America there are insufficient hemp hurds available to meet market demand.
Only since the flower-power-time of the 1960s, the smoking of Cannabis as a recreational drug has become a widely known phenomenon in the Western world. From then on, import of stronger varieties from the tropics, combined with a growing expertise in breeding and cultivation, led to a steady increase in psychoactive potency. Contemporary recreational Cannabis has increasingly become a high-tech crop, grown indoors under completely artificial conditions.
Parkinson’s disease. Some early research shows that taking cannabidiol daily for 4 weeks improves psychotic symptoms in people with Parkinson’s disease and psychosis. But taking a specific cannabis extract (Cannador) that contains THC and cannabidiol does not appear to improve involuntary muscle movements caused by the anti-Parkinson’s drug levodopa in people with Parkinson’s disease.
In addition to safety risks, many jobs also present risks of disease, illness and other long-term health problems. Among the most common occupational diseases are various forms of pneumoconiosis, including silicosis and coal worker's pneumoconiosis (black lung disease). Asthma is another respiratory illness that many workers are vulnerable to. Workers may also be vulnerable to skin diseases, including eczema, dermatitis, urticaria, sunburn, and skin cancer. Other occupational diseases of concern include carpal tunnel syndrome and lead poisoning.