The administration of liquid cannabis extracts containing THC is associated with the mitigation of various symptoms of Alzheimer’s-related agitation and dementia, according to observational trial data published online ahead of print in The Journal of Alzheimer’s Disease.
Israeli investigators assessed the use of cannabis oil as an adjunct pharmacotherapy treatment in ten Alzheimer’s disease patients over a period of several weeks. Researchers reported that drug administration was associated with a significant reduction in patients’ symptom severity scores. Specifically, cannabis oil ingestion corresponded with decreased levels of aggression, irritability, apathy, and delusions.
Investigators concluded, “Adding medical cannabis oil to Alzheimer’s disease patients pharmacotherapy is safe and a promising treatment option.”
The administration of dronabinol (oral synthetic THC in pill form) has previously been reported to reduce Alzheimer’s-induced agitation and improve weight gain, while preclinical studies have theorized that cannabinoids may be neuroprotective against the onset of the disease.
An abstract of the study, “Safety and efficacy of medical cannabis oil for behavioral and psychological symptoms of dementia: An open label, add-on, pilot study,” appears online here.
Investigators at the University of California, Los Angeles and the University of Minnesota evaluated whether marijuana use was associated with changes in intellectual performance in two longitudinal cohorts of adolescent twins. Participants were assessed for intelligence at ages 9 to 12, before marijuana involvement, and again at ages 17 to 20.
Researchers reported no dose-response relationship between cannabis use and IQ decline. They also found no significant differences in performance among marijuana using subjects when compared to their non-using twins.
Investigators concluded: “In the largest longitudinal examination of marijuana use and IQ change, … we find little evidence to suggest that adolescent marijuana use has a direct effect on intellectual decline. … [T]he lack of a dose–response relationship, and an absence of meaningful differences between discordant siblings lead us to conclude that the deficits observed in marijuana users are attributable to confounding factors that influence both substance initiation and IQ rather than a neurotoxic effect of marijuana.”
The findings follow the publication of a separate longitudinal study in the Journal of Pharmacology which concluded that cumulative adolescent marijuana use is not associated with lower IQ or poorer educational performance once adjustments are made for potential confounders, specifically cigarette smoking.
An abstract of the study, “Impact of adolescent marijuana use on intelligence: Results from two longitudinal twin studies,” is online here.
Researchers from Texas A&M University and the University of Florida, Gainesville evaluated drug use patterns from a nationally representative sample of 2,835 12th graders.
Authors found that youth use of alcohol most often preceded the use of tobacco or marijuana. They also reported subjects’ age of alcohol initiation is the strongest predictor of later polydrug use.
“Alcohol is the most commonly used substance, and the majority of polysubstance using respondents consumed alcohol prior to tobacco or marijuana initiation,” they reported. “Respondents initiating alcohol use in sixth grade reported significantly greater lifetime illicit substance use and more frequent illicit substance use than those initiating alcohol use in ninth grade or later.”
They concluded, “Our results … assert that the earlier one initiates alcohol use, the more likely that they will engage in future illicit substance use.”
The findings are inconsistent with recent claims made by several prominent lawmakers that cannabis is a ‘gateway’ to later substance abuse.
Studies conducted by the RAND Corporation and others have previously dismissed any alleged causal role of marijuana as a gateway to subsequent illicit drug abuse, finding, “There is no conclusive evidence that the drug effects of marijuana are causally linked to the subsequent abuse of other drugs.”
An abstract of the study, “Prioritizing Alcohol Prevention: Establishing Alcohol as the Gateway Drug and Linking Age of First Drink With Illicit Drug Use,” appears online here.
Marijuana use by adolescents is not associated with lower IQ or poorer educational performance once adjustments are made for potential confounders, specifically cigarette smoking, according to longitudinal data published online ahead of print in the Journal of Psychopharmacology.
British investigators assessed the relationship between cumulative cannabis use and IQ at the age of 15 and educational performance at the age of 16 in a cohort of 2,235 adolescents.
After researchers adjusted for potentially confounding variables, such as childhood depression and cigarette use, they reported, “[T]hose who had used cannabis [greater than or equal to] 50 times did not differ from never-users on either IQ or educational performance.”
By contrast, teen cigarette smoking was associated with poorer educational outcomes even after researchers adjusted for other confounding variables.
Researchers concluded, “In summary, the notion that cannabis use itself is causally related to lower IQ and poorer educational performance was not supported in this large teenage sample.”
A widely publicized New Zealand study published in 2012 in The Proceedings of the National Academy of Sciences reported that frequent use of cannabis by those under the age of 18 was associated with lower IQ by age 38. However, a separate review of the data published later in the same journal suggested that the changes were likely the result of socioeconomic differences, not cannabis use.
More recently, the results of a 2015 study in the journal Drug and Alcohol Dependence reported that the effects of persistent adolescent cannabis use on academic performance “became non-significant after controlling for persistent alcohol and tobacco use.”
Full text of the study, “Are IQ and educational outcomes in teenagers related to their cannabis use? A prospective cohort study,” appears online here.
Cannabis administration is associated with decreased migraine headache frequency, according to data published online ahead of print in the journal Pharmacotherapy.
Investigators at the University of Colorado, Skaggs School of Pharmacy and Pharmaceutical Sciences retrospectively assessed cannabis’ effects on monthly migraine headache frequency in a group of 121 adults. Study participants had a primary diagnosis of migraine headache, had been recommended cannabis by a physicians for migraine treatment, and had participated in at least one follow up medical visit.
Authors reported that 85 percent of subjects reported a decrease in migraine frequency and 12 percent indicated that the use of cannabis prior to migraine onset would abort headaches.
“Migraine headache frequency decreased from 10.4 to 4.6 headache per month with the use of medical marijuana,” researchers concluded. “Further research should be performed to determine if there is a preferred delivery method, dose, and strain of medical marijuana for migraine headache therapy as well as potential long-term effects of medical marijuana.”
Although case reports have previously documented the effect of cannabinoids for migraine relief, no prospective trials have yet to evaluate cannabis use in migraine patients. Nonetheless, scientists for some time have theorized that cannabinoids may play a role in migraine regulation. Writing in 2007 in the European Journal of Critical Pharmacology, Italian researchers reported that patients with chronic migraines possessed significantly lower levels of the endogenous cannabinoids anandamide and 2-arachidonylglycerol (2-AG) in their platelets compared to age-matched controls. “These data support the potential involvement of a dysfunctioning of the endocannabinoid and serotonergic systems in the pathology of chronic migraine and medication-overuse headaches,” authors concluded.
The abstract of the study, “Effects of medical marijuana on migraine headache frequency in an adult population,” appears online here.