CCR: Some users describe the psychoactive effects of Cannabis indica and sativa as being distinctive, even opposite. But are they really? Beyond self-reports from users, is there any hard evidence for pharmacologically different species of Cannabis?
Dr. Russo: There are biochemically distinct strains of Cannabis, but the sativa/indica distinction as commonly applied in the lay literature is total nonsense and an exercise in futility. One cannot in any way currently guess the biochemical content of a given Cannabis plant based on its height, branching, or leaf morphology. The degree of interbreeding/hybridization is such that only a biochemical assay tells a potential consumer or scientist what is really in the plant. It is essential that future commerce allows complete and accurate cannabinoid and terpenoid profiles to be available.
CCR: Sativa is often described as being uplifting and energetic, whereas indica as being relaxing and calming. Can you speculate on what could be the basis for these perceived differences?
Dr. Russo: We would all prefer simple nostrums to explain complex systems, but this is futile and even potentially dangerous in the context of a psychoactive drug such as Cannabis. Once again, it is necessary to quantify the biochemical components of a given Cannabis strain and correlate these with the observed effects in real patients. Beyond the increasing number of CBD predominant strains in recent years, almost all Cannabis on the market has been from high-THC strains. The differences in observed effects in Cannabis are then due to their terpenoid content, which is rarely assayed, let alone reported to potential consumers. The sedation of the so-called indica strains is falsely attributed to CBD content when, in fact, CBD is stimulating in low and moderate doses! Rather, sedation in most common Cannabis strains is attributable to their myrcene content, a monoterpene with a strongly sedative couch-lock effect that resembles a narcotic. In contrast, a high limonene content (common to citrus peels) will be uplifting on mood, while the presence of the relatively rare terpene in Cannabis, alpha-pinene, can effectively reduce or eliminate the short-term memory impairment classically induced by THC.2,8
CCR: How do you think one could address the sativa/indica dichotomy in a scientifically sound manner?
Dr. Russo: Since the taxonomists cannot agree, I would strongly encourage the scientific community, the press, and the public to abandon the sativa/indica nomenclature and rather insist that accurate biochemical assays on cannabinoid and terpenoid profiles be available for Cannabis in both the medical and recreational markets. Scientific accuracy and the public health demand no less than this.
