When it comes to research on psychedelics, almost all of the attention goes  to their therapeutic potential.

You might not expect that “bad trip” you had  at a rave to be of much academic interest. But bad trips are common and can result  in serious distress or even death.

So some scientists have been trying  to figure out what causes them. And you weren't hallucinating when  you saw the title of this video ... they think they've found it. [♪ INTRO] Magic mushrooms, LSD, ecstasy, mescaline. The compounds in all of these  psychedelic drugs may differ, but they tend to produce  pretty similar experiences.

Despite the fact that they’re illegal  and unregulated in many places, that isn’t stopping people from using them. And it sure isn’t stopping people  from having bad trips in the process. What do people mean when they  say they’ve had a bad trip?

Psych researchers prefer the term “challenging  experiences”, and those experiences can come with a whole host of different  symptoms: increased heart rate, panic, mood changes like sudden anger or sadness,  and a scary thing called ego dissolution. That last one, also called ego death, is a  dramatic alteration in how you perceive yourself. You sort of lose your sense of self entirely.

While it isn’t always negative, ego dissolution  and other elements of bad trips have led to some incredibly dangerous experiences,  including suicides and accidental deaths. And a bad trip isn’t always over when it’s over. By that I mean, people can continue to  be negatively affected by psychedelics long after the drugs should have worn off.

In one study, almost 9% of  participants reported having bad trips that led to functional  impairments for more than a day. In another study, users reported  increased levels of anxiety, struggles with social interactions,  problems thinking clearly, and other difficulties for weeks to  years following the use of psychedelics. Bad trips are fairly common, too.

One study found that about 40% of their  participants who used psychedelics had experienced one at some point. So the big question is, why do these things  happen to some people and not others? There are a number of factors involved, and  not all of those have been fully determined.

But it won’t surprise you to learn that  neurotransmitters are at least part of the answer. The most famous neurotransmitter  associated with psychedelics is serotonin. That’s the one often associated with happiness.

You’ll see a lot of people mention  getting a “boost” of serotonin from endlessly scrolling for memes. It’s me, I’m people. Psychedelic drugs trigger the  serotonin receptors in your brain, which are involved with mood and memory.

That may be partly responsible for the high experienced by many people who take these drugs. But recently, studies have shown  that a less famous neurotransmitter is correlated with bad trips: glutamate. Thank you to our incredible patrons on Patreon, like the Presidents of Science,  McLaren Stanley and Charlie Stanley!

In most cases you can only have  one president in office at a time. But science transcends those  rules. It answers to accuracy.

If you'd like to become the  next President of Science, doing what you can to fill your  algorithm with accurate stories, you can start your campaign  at patreon.com/SciShow. Let’s be clear, glutamate is pretty  much everywhere in your brain! It is an excitatory neurotransmitter.

It’s like an “on” switch, meaning it triggers  various activities in your central nervous system. So just having a lot of it doesn’t tell us much. But one study looked at the level of glutamate in a specific part of the  brain after using psychedelics.

The study gathered people  who had previous experience with the drugs and gave half of them a  psychedelic and the other half a placebo. Each participant got an MRI scan when the drug  effects were believed to be at their peak. Comparing scans with the experience of  the participants, the researchers found that people who had higher levels of  glutamate in the medial prefrontal cortex were more likely to experience  negative ego dissolution.

Now, the brain has created some complex  and confusing words to describe itself. So let’s briefly break down what  the medial prefrontal cortex is. Believe it or not, it’s right at the  front of your brain, in your frontal lobe.

And the medial prefrontal cortex is involved  with emotional regulation, among other things. Those elevated glutamate levels in  this region were strong predictors of increased levels of anxiety in participants, because glutamate controls  behaviors associated with stress. Basically, it turned “on” that anxiety.

So that may have contributed to their bad trips. I know there are evolutionary  benefits to stress and anxiety, but sometimes I really wish  they didn’t have an on switch. There are also non-brain chemistry factors that may contribute to someone’s  likelihood of having a bad trip.

Researchers suggest that high  dosages may lead to them. If too much of a good thing is bad, too much of an illegal and unregulated  substance probably isn’t great either. People who study this also emphasize  the importance of “set and setting”, “set” being the person’s mood and mental state and “setting” being the physical environment  in which someone is taking the drug.

Basically, if you’re going to take  psychedelics, the general recommendation is to be in a generally positive  state of mind and a safe place. Now are bad trips really all that bad? Yes, absolutely, they are  terrifying and dangerous!

But that’s not to say it’s  impossible to pull something valuable from said terrifying and dangerous experience. Some people have reported bad  trips opening their minds to things they have repressed, allowing  them to work through those challenges. Others report that ego dissolution  provided them the opportunity to look at themselves from a different  perspective, giving them the space to make positive changes in  themselves and their mental state.

Those are the kinds of experiences  that are believed to make psychedelics useful for therapeutic purposes. They’re being studied as treatments  for disorders such as depression, anxiety, addiction, and post  traumatic stress disorder. It’s incredibly important to recognize the risks  involved with the use of psychedelic drugs.

But we're making progress in our journey to understand these chemicals and our own brains. And that's not such a bad trip to be on. [♪ OUTRO]