Making the connection

The findings of new US research will surely feed into the debate about whether it is better to take your cannabis neat, as generally in North America, or mixed with tobacco, the European way.
According to a story at sciencedaily.com, researchers at the Center for BrainHealth® at the University of Texas, Dallas, investigated the effects on the brain of concurrent cannabis and nicotine use, versus the use of solely cannabis and solely nicotine.
The results, recently published in the journal Brain Structure and Function, apparently show that not only were the effects in these three categories different, but also that the group using both nicotine and cannabis more closely resembled the control (non-user) group in brain connectivity. The isolated nicotine and isolated cannabis users showed equally less connectivity in general.
‘Previous research in rats has suggested that nicotine may be a ‘gateway drug’ leading to cannabis and other drug use,’ the story reports.
‘Studies performed with rats exposed to THC – the main psychoactive compound found in marijuana – demonstrated an increased likelihood to self-administer nicotine that was not observed with rats exposed to heroin or cocaine, suggesting that there is something unique about the cannabis-nicotine interaction.’
“Most of the literature to date has focused on associations of isolated cannabis and nicotine use, even though concurrent cannabis and nicotine use is more prevalent in society than cannabis use alone,” said the study’s lead author, Dr. Francesca M. Filbey, the Bert Moore Chair in BrainHealth at UT Dallas. “Our findings confirm the limitations of existing research.”
While the outcome of the study could be, in part, due to the opposing effects nicotine and cannabis have on the brain, the difference in the brains of concurrent users versus isolated users of each product begs for further research in functional connectivity metrics in these populations, Filbey added.