Once again the gateway theory—the belief that cannabis use leads to other drugs, popularized about 40 years ago—is being crushed by new evidence, this time finding no evidence of worsened drug abuse in legal states, using twins as controls. 

A new long-term study examined sets of twins, over 4,000 individuals, and found that state legalization status wasn’t associated with a rise in substance-use disorders of other drugs, and other psychological problems and vulnerabilities. Researchers also noted that legalization led to an increase in cannabis use but decrease in alcohol use disorder (AUD). 

The study, “Recreational cannabis legalization has had limited effects on a wide range of adult psychiatric and psychosocial outcomes,” was published online by Cambridge University Press on Jan. 5. In it, researchers sought to “quantify possible causal effects of recreational cannabis legalization on substance use, substance use disorder, and psychosocial functioning, and whether vulnerable individuals are more susceptible to the effects of cannabis legalization than others.”

Addiction usually goes well beyond the substances involved: The Colorado Sun reports that researchers measured general psychological dysfunction, going beyond substance-use disorders but also measuring financial problems, mental health, community disengagement, and relationship issues that are sometimes believed to be linked to pot use.

After noting that twins consumed cannabis about 20% more in legal states than non-green states in a previous study, the same team of researchers set out again to see if this impacts addiction of other substances, and other psychiatric disorders.

Researchers gathered data from longitudinal studies of twins in two opposing states, one with legal pot and one without: Colorado or Minnesota. The states provided near-perfect controls to examine the full effects of legalization versus a state that prohibits most forms of cannabis. Researchers in both states observed the twins over long periods of time. By using twins there are more automatic controls over socioeconomic status or genetic differences.

Researchers gathered data from 4,078 individuals, first assessed in adolescence and now ages 24-49, and currently residing in states with different cannabis policies (Colorado or Minnesota). Study participants were recruited as teens via birth records from the years 1972–1994, beginning before 2014, when adult-use cannabis stores opened in Colorado. Parents provided informed consent when the study participants were minors.

Living in a legal state was “not associated” with substance abuse disorders, although they found it led to higher pot use but lower alcohol use. Living in a legal state was associated, in fact, with lower AUD rates.

“In the co-twin control design accounting for earlier cannabis frequency and alcohol use disorder (AUD) symptoms respectively, the twin living in a recreational state used cannabis on average more often, and had fewer AUD symptoms than their co-twin living in an non-recreational state. Cannabis legalization was associated with no other adverse outcome in the co-twin design, including cannabis use disorder. No risk factor significantly interacted with legalization status to predict any outcome.”

This led researchers to come to several conclusions.

“Recreational legalization was associated with increased cannabis use and decreased AUD symptoms but was not associated with other maladaptations,” wrote researchers. “These effects were maintained within twin pairs discordant for residence. Moreover, vulnerabilities to cannabis use were not exacerbated by the legal cannabis environment. Future research may investigate causal links between cannabis consumption and outcomes.”

While living in a legal state was associated with higher pot use, it didn’t impact drug abuse and other psychological problems. “At least from the psychological point of view,” Stephanie Zellers, one of the researchers, told The Colorado Sun. “We really didn’t find that the policies (on cannabis legalization) have a lot of negative influence, which I think is important.”

“That twin component really allows us to rule out a lot of possible alternatives—maybe there were just cultural differences, family differences, things like that,” Zellers said, explaining the need to observe twins.

Zellers also led the earlier study looking at the impact of legalization. The team has funded much of the research based on grants from the National Institutes of Health. 

Researchers stipulate that more data is needed to determine the effects of cannabis legalization regarding psychiatric disorders and addiction. 

The post Long-Term Study of Twins Finds No Link Between Legalization, Drug Abuse appeared first on High Times.

The post Long-Term Study of Twins Finds No Link Between Legalization, Drug Abuse appeared first on Paradise Found.

A new study published in the journal Addiction on Aug. 24 analyzed cannabis consumption data across the nation, with a specific focus on adult identical twins. Called “Impacts of recreational cannabis legalization on cannabis use: a longitudinal discordant twin study,” the study used twins to explore the frequency of cannabis across two different states.

“In this study, we evaluated the effects of recreational cannabis legalization in a large sample of prospectively assessed adult twins from similar cohorts of individuals born in Colorado and Minnesota, demographically similar states with different cannabis policies,” the researchers presented in their introduction. “While many participants still reside in their birth states, some participants have migrated to other states resulting in pairs discordant for exposure to recreational legalization.”

Researchers reviewed data from either the Minnesota Center for Twin Family Research or the University of Colorado, Boulder Center for Antisocial Drug Dependence, with a total of 3,452 individuals (split between 1,700 individuals from Minnesota and 1,752 from Colorado). All individuals had previously been asked about their cannabis use before and after 2014, when the state of Colorado legalized recreational cannabis, and Minnesota legalized medical cannabis. Of this number, there was a split among different types of twins: monozygotic (363 pairs), same-sex dizygotic (208) pairs and opposite-sex dizygotic (129 pairs).

The researchers concluded that in 111 pairs of twins, there were no genetic influences that led to cannabis consumption frequency, however they did confirm that “Existing genetic influences were moderated by the legal environment, as the genetic correlation between marijuana use before and after legalization was lower in states that legalized compared with states that did not.”

“Using a longitudinal design accounting for age, sex and earlier cannabis use, we found a ~24% increase in mean cannabis use frequency attributable to legalization,” researchers explained. “Furthermore, co-twin control results indicate that within monozygotic pairs, the twin living in a legal state uses cannabis ~20% more frequently than their illegally residing co-twin.”

However, the researchers also noted that nearly 92% of participants were white and projected how the inclusion of more non-white participants could alter the results. “An important extension of our work would be to investigate individual differences in the context of cannabis policy with respect to sex or racial background. Prior to recreational legalization, black Americans disproportionately bore the consequences of cannabis law enforcement,” researchers wrote. “Racial disparities in pre-legalization enforcement could mean that the legalization-related environmental changes experienced by black Americans were more dramatic than those experienced by their white counterparts, but we are not able to address this issue effectively in these samples.”

In their conclusion, researchers stated that this particular topic could use more elaboration to further understand how cannabis may have affected people in other states. “Through the use of zygosity-stratified co-twin control analyses, we found a ~20% increase in cannabis use frequency, consistent with a causal effect of recreational legalization,” they wrote. “These results do not, by themselves, demonstrate how more frequent use in legal states translates to changes in health or behavioral consequences, therefore future work is necessary to further address complex questions around the public health impacts of legalization and vulnerability to widely available marijuana.”

On Aug. 24, a new study from the National Institutes of Health found that consumption of cannabis and hallucinogens is at an all-time high for individuals between the ages of 19-30. Researchers said that consumption in this age group has “increased significantly in 2021 compared to five and 10 years ago,” and is the highest level of consumption since 1988.

National Institute on Drug Abuse Director Nora Volkow said in an accompanying statement that this research is crucial to understanding the long-term effects of cannabis on youth. “As the drug landscape shifts over time, this data provides a window into the substances and patterns of use favored by young adults. We need to know more about how young adults are using drugs like marijuana and hallucinogens, and the health effects that result from consuming different potencies and forms of these substances,” Volkow said. “Young adults are in a critical life stage and honing their ability to make informed choices. Understanding how substance use can impact the formative choices in young adulthood is critical to help position the new generations for success.”

The post Study Shows 20% Increase in Frequency of Cannabis Consumption in Recreational States appeared first on High Times.

The post Study Shows 20% Increase in Frequency of Cannabis Consumption in Recreational States appeared first on Paradise Found.