The chemical serotonin, a neurotransmitter in the brain that plays a role in the emotions and behavior, is gradually being linked to anxiety and stress in general as scientists are uncovering common ways it may be responding to life’s stresses, according to a recent study.
In a study published last month in the journal Psychoneuroendocrinology, researchers at the University of Copenhagen in Denmark found that individuals with PTSD had higher levels of serotonin in their brains than non-PTSD patients. One of the mechanisms for this surprising finding, the researchers said, is the hope that MDMA, a drug commonly known as ecstasy, might be one route by which a very low dose of serotonin could be used as a countermeasure to the disease.
The study was prompted, in part, by the recent release of “Resident Evil: The Final Chapter,” the latest installment in the video game franchise, which includes a scene in which a character (played by Canadian actress Milla Jovovich) who suffers from PTSD takes ecstasy. After spending a few minutes on the drug, she realises that she has invaded the body of an infected woman from the game. Her emotionally charged interaction with the digital counterpart ends with the real one threatening her with a knife. “PTSD is real,” she tells the virtual personality.
To test the suggestion that MDMA might be an effective treatment for PTSD, the researchers administered small doses of the drug to healthy volunteers through “drug suspension” — they were tricked into believing that the drug had been removed from their body before being administered to them. They observed the levels of serotonin in participants’ brains as they went through a series of tests.
Some participants took MDMA orally, while others took just a single injection of it. Those who injected themselves on average had 4.4 milligrams of serotonin per deciliter of blood. Those who took the oral drug had slightly higher levels (4.6 milligrams per deciliter of blood).
Overall, of the participants in the study, 71 percent took oral MDMA, 29 percent took the injection, and 17 percent took both injections. This meant that 44 percent, or those who took both the drug and the oral drug, ended up getting higher levels of serotonin in their brains. On average, they had 10 percent more serotonin in their bodies after taking the oral drug, and about 18 percent more of the chemical when they injected themselves.
An analysis of the research further revealed that PTSD patients had significantly higher levels of serotonin when they took the drug orally. On average, they had 7.4 milligrams of serotonin per deciliter of blood when they injected themselves, but in the people who took the oral drug and both injections, the average was 7.7 milligrams per deciliter of blood. “The subjects who took just the oral drug showed only a few increases in their serum concentration, and those who took both the oral and needle injected [sic] drug groups had significantly larger increases in their serum concentration,” the researchers wrote.
The researchers found that the drug decreased sensitivity to stimuli, and increased the amygdala, the brain region that plays a role in fear processing. It also increased activity in the hippocampus, another brain region that plays a role in storing memories. “On the whole, the serotonin animals were shown to be able to delay arousal levels and prolong positive moods under stress,” the researchers wrote.
They conclude: “We find convincing evidence for the potential antidepressant effect of the heroin-like drug (MDMA) on those who suffer from PTSD, both in individuals who did not have PTSD in the first place and in individuals who did suffer from PTSD.”