A new target for marijuana

Cellular-level changes to a part of the brain’s reward system induced by chronic exposure to the psychoactive component of marijuana may contribute to the drug’s pleasurable and potentially addictive qualities, suggests a study in young mice published in JNeurosci. The results could advance our understanding of marijuana’s effects on the developing brain as the drug’s rapidly changing legal status increases its recreational and medical use in the United States.

Drugs of abuse impact the ventral tegmental area (VTA) of the brain, which is rich in dopamine neurons. Using juvenile and adolescent mice, Jeffrey Edwards and colleagues investigated the effects of tetrahydrocannabinol (THC), the chemical in marijuana responsible for its effects on cognition and behavior, on VTA GABA cells, an understudied inhibitory cell type in the reward system that regulates dopamine levels.

Full story at Science Daily

Marijuana may produce psychotic-like effects in high-risk individuals

Marijuana may bring on temporary paranoia and other psychosis-related effects in individuals at high risk of developing a psychotic disorder, finds a preliminary study from researchers at Columbia University Medical Center (CUMC).

The study was published last month in an online edition of Psychiatry Research.

Individuals who have had mild or transient psychotic symptoms (such as unusual thoughts, suspiciousness, perceptual disturbances) without using substances such as marijuana or alcohol and have a family history of psychosis or other risk factors are considered at clinical high risk for psychotic disorder. Previous studies have found an association between marijuana use and psychosis in the general population, but none have rigorously examined marijuana’s effects in those at greatest risk for psychosis.

Full story at Science Daily

Compound derived from marijuana interacts with antiepileptic drugs

New research published in Epilepsia, a journal of the International League Against Epilepsy (ILAE), suggests that an investigational neurological treatment derived from cannabis may alter the blood levels of commonly used antiepileptic drugs. It is important for clinicians to consider such drug interactions during treatment of complex conditions.

Cannabidiol (CBD), a compound developed from the cannabis plant, is being studied as a potential anticonvulsant, and it has demonstrated effectiveness in animal models of epilepsy and in humans. An ongoing open label study (Expanded Access Program) conducted by investigators at the University of Alabama at Birmingham is testing the potential of CBD as a therapy for children and adults with difficult to control epilepsy. The study includes 39 adults and 42 children, all of whom receive CBD.

Because all of the participants are also taking other seizure drugs while they are receiving the investigational therapy, investigators checked the blood levels of their other seizure drugs to see if they changed. “With any new potential seizure medication, it is important to know if drug interactions exist and if there are labs that should be monitored while taking a specific medication,” said lead author Tyler Gaston, MD.

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Rates of marijuana use, heavy use, and cannabis use disorder depend on where you live

Adult marijuana use rose significantly in states that passed loosely regulated medical marijuana laws (MMLs) according to a new study by Columbia University’s Mailman School of Public Health and Columbia University Medical Center. Highest increases were reported among adults ages 26 and over. Little change was found in past-month marijuana use among adolescents or young adults between the ages 18 and 25. The findings are published online in the journal Addiction.

Adults 26 years of age and older living in states with less regulated medical marijuana programs increased past-month marijuana use from 4 percent to 6.59 percent after the laws were enacted. No significant change was found in the prevalence of cannabis use disorder among adolescents or adults after states enacted medical marijuana laws, regardless whether programs were highly regulated or “loose.”

Using data from the National Survey of Drug Use and Health from 2004-2013 the researchers analyzed trends over time with particular emphasis on age groups. This included obtaining prevalences of marijuana use outcomes at the state level by year and whether the enacted laws included a highly regulated (“medicalized”) or less regulated (“non-medical”) program. Participants were classified as having marijuana abuse or dependence based on DSM-IV criteria.

Full story of marijuana use rates depending on location at Science Daily

Why the marijuana and tobacco policy camps are on very different paths

The regulatory approaches to marijuana and tobacco in the United States are on decidedly different paths and, according to researchers from the U.S. and Australia, neither side appears interested in learning from the other.

“The two policy communities have shown very little interest in each other’s policy debates,” Wayne Hall and Lynn Kozlowski write in a new paper published in the journal Addiction.

Hall, the lead author, is a professor at the Centre for Youth Substance Abuse Research at the University of Queensland, Australia, and is an expert on marijuana and other drug use issues. Kozlowski is professor of community health and health behavior in the University at Buffalo’s School of Public Health and Health Professions and an expert on tobacco use and control.

Full story of marijuana and tobacco policy camps at Science Daily