People naturally have all sorts of weird thoughts, but sometimes these become intrusive and upsetting enough to rise to the level of a disorder. And while it's not possible (or ethical) to make anyone paranoid just to experiment on them, fortunately some scientists have realized that studying stoners can help us understand paranoid mental illness. As many casual users have discovered on their own, marijuana not infrequently has paranoia-inducing effects, and these provide clues as to what's going on in the brain in more serious, ongoing cases of paranoia.
Interestingly, paranoid thoughts are actually pretty common, with 5 to 50 percent of adults regularly having them. The percentage seems to be on the rise, perhaps because our modern world is a complicated one providing lots of ambiguous clues that our brains are eager to find meaning in (for instance, being asked to stay on the lookout for suspicious packages and people when we're in public because of terrorist threats). It's just that most people don't really act on these thoughts, for instance by staying home all the time, disguising their appearances, or engaging in other life-disrupting tasks to ward off the bad guys. That's where paranoia rises to the level of an actual disorder.
So where does the marijuana come in? Well, people who have mental disorders are somewhat more likely to use cannabis in the first place, often apparently in an attempt to self-medicate unpleasant psychological symptoms away. But research also suggests that 15 percent of marijuana users may develop new paranoid symptoms upon use, and these mostly go away when the marijuana wears off (with a few unfortunate cases of permanent paranoia resulting from marijuana use).
Though additional research is sorely needed, marijuana might be implicated in the same "excessive synaptic pruning" involved in mental illness. With their connections disrupted, different cells in the brain struggle to biochemically convey the information that might assuage one's instinctive paranoid responses to her environment. As Natalie Zarelli explains at Pacific Standard:
"Cannabis use can cause a signal miscommunication in the brain, which is similar to what might happen in mental illness...neurons can’t send the information that aids in the correct perception of a person’s surroundings and situation."
If you've had a paranoid response to marijuana in the past, then, you may want to stay away from this drug from now on. Though many people's marijuana-induced paranoia turns out to be temporary and there might be treatments to undo excessive synaptic pruning in the works, the stakes are a little too high for it to be worth it. Hopefully in time this line of inquiry will generate better tools for alleviating paranoia in stoners and non-stoners alike. For now, it pretty much just drives home how little we know about the difference between normal and pathological paranoia.
Image: Yeko Photo Studio/Fotolia, Giphy