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Cannabis flower with an equal balance of CBD and THC is less likely to cause anxiety, paranoia, or other adverse effects, according to a new study published in the Addiction Biology journal. 

Researchers from the University of Colorado’s Anschutz Medical Campus set out to test claims that high-CBD cannabis could help mitigate some of the adverse effects occasionally associated with weed. For the study, researchers recruited 159 regular cannabis users and asked them to smoke one of three different strains of weed. One of these chemovars was THC-dominant, with 24 percent THC and 1 percent CBD, one had a fairly equal balance of 10 percent THC to 9 percent CBD, and the third had 23 percent CBD but only 1 percent THC.

The ongoing federal prohibition of cannabis makes it excessively difficult for institutions to access high quality cannabis for research (although that may soon change). To get around these restrictions at the time of the study, the researchers asked subjects to smoke up in their own homes. Using a mobile pharmacology lab, researchers took blood samples from the participants right before they lit up, and took a second sample one hour after they got high. 

During the second visit to the mobile lab, subjects were asked to relate the subjective experiences they felt after getting blazed. Those who smoked the 1:1 THC:CBD blend reported significantly fewer negative effects, including anxiety and paranoia, than the subjects who hit the high-THC bud. 

And, perhaps most interestingly, the subjects who smoked the equal-ratio strain also had lower THC levels in their blood after smoking. But despite the decrease in THC plasma levels, these participants reported feeling just as pleasantly stoned as those who smoked the THC-dominant strain. 

“This is one of the first studies to examine the differential effects of various THC to CBD ratios using chemovars that are widely available in state-regulated markets,” the researchers wrote. “Individuals using a THC + CBD chemovar had significantly lower plasma THC concentrations and reported less paranoia and anxiety while also reporting similar positive mood effects as compared to individuals using THC only.”

Several previous studies have found that CBD can reduce symptoms of psychosis, possibly by reducing activity in specific areas of the brain. These studies have led researchers to speculate that cannabis strains that are high in CBD may actually mitigate anxiety, paranoia, or other negative feelings that some cannabis users experience. If true, these findings imply that cannabis strains with equal balances of critical cannabinoids could be ideal for a wider variety of medical marijuana patients.

The authors of the present study suggest that “the harm reduction implication of these findings is that cannabis chemovars containing CBD may result in less overall exposure to THC and subsequently less potential for harm, particularly with respect to the psychotomimetic effects of THC.”