Cannabis

A field in flux.

The cannabis compound known as CBD is being touted as a treatment for a variety of conditions. But the substance’s uncertain legal status is stalling serious investigation.

Genetic modification could enable industrial-scale production of cannabinoids that have pharmaceutical potential.

With its demand for water, land and artificial lighting, cannabis growing can leave a large environmental footprint. But heightened awareness could make cultivation more benign.

As the wave of legalization advances, a budding industry is adopting the high standards of consumer-product makers to meet regulatory requirements.

The notion of an ‘entourage effect’ that magnifies the drug’s effects is intriguing but lacks solid evidence.

Scientists investigate the counter-intuitive connections between exercise and cannabis.

As interest builds in the potential health benefits from the plant, accumulating evidence confirms that taking the drug also carries risks.

Policy changes are needed to support crucial work in the United States, says Jahan Marcu.

Highlights from laboratory studies and clinical trials.

Genetic engineering of yeast enables the production of cannabinoids and cannabinoid analogues from the simple sugar galactose, without the need to cultivate Cannabis.

In mice aged 12–18 months, chronic administration of low-dose Δ⁹-tetrahydrocannabinol (THC) improves performance in behavioral learning and memory tasks, whereas a similar administration in younger mice (aged 2 months) impairs performance.

The study reports a genome-wide significant locus for cannabis use disorder, replicating in an independent cohort, and implicates CHRNA2, which encodes an acetylcholine receptor subunit, in the disorder by analyses of genetically regulated gene expression.

Therapeutic application of cannabis remains controversial despite evidence of pain-relieving functions, particularly for rheumatic diseases. However, whether cannabis can also be used as an immunomodulatory therapeutic agent needs to be counterbalanced by risk assessment for adverse effects.

Over the past decade, marijuana has been legalized for medicinal purposes or recreational use in many countries, and the potency of marijuana and synthetic cannabinoids has substantially increased. In this Review, Pacher and colleagues summarize the role of the endocannabinoid system in cardiovascular health and disease, and critically discuss the beneficial and detrimental cardiovascular effects of marijuana and synthetic cannabinoid use.

A GWAS of lifetime cannabis use reveals new risk loci, shows that cannabis use has genetic overlap with smoking and alcohol use, and indicates that the likelihood of initiating cannabis use is causally influenced by schizophrenia.