Everyone knows what it's like to worry about something incessantly, even if you repeatedly tell yourself to stop, just like that one song you keep replaying over and over in your head. While rumination and intrusive thoughts are common symptoms of certain psychiatric disorders like schizophrenia and PTSD, they also affect those suffering from even mild anxiety and depression.
What is GABA?
And now, a 2017 study may have found the key to why negative thoughts persist in some people over others. One team of researchers from the University of Cambridge identified the brain neurotransmitter responsible for controlling unwanted thoughts: GABA. It's short for gamma-Aminobutyric acid, and according to BBC, "The discovery may help explain why some people can't shift persistent intrusive thoughts." And it is this kind of self-regulation that's considered "fundamental to wellbeing."
In the study, published in the journal Nature, researchers asked participants to associate a series of words with a paired but otherwise unconnected word. Next, they were asked to a respond to a red or green signal. Green meant they should recall the associated words, while red meant participants should stop themselves from doing so. During the exercise, the scientists monitored the participants's brains using functional magnetic resonance imaging (FMRI) to detect changes in blood flow in the brain, and magnetic resonance spectroscopy, which measures and chemical changes in the brain.
In the end, those with higher concentrations of GABA, known as the "inhibitory" neurotransmitter, in the hippocampus region of the brain, were best at blocking unwanted thoughts or memories. The hippocampus is one of the areas of the brain responsible for memory, and it plays an important role in decision-making. Meaning, when GABA is released in the brain, it has the capacity to override activities of other parts of the brain (like the part replaying those intrusive thoughts, images, and memories.)
Not enough GABA in the brain, on the other hand, might mean negative thoughts slip through the the neurotransmitter's "safety net." Big Think writes, "Caffeine inhibits the release of GABA in the brain, so one way to conceptualize what a GABA deficiency might feel like is to imagine that jittery, hyperactive feeling when you drink too much coffee."
Why GABA Matters
Identifying the neurotransmitter that is most likely the key to regulating rumination is significant because it narrows the origin of an issue scientists have been focusing on for years. It also means science just got one step closer to possible treatments by honing in on the GABA neurotransmitter.
"Before, we could only say 'this part of the brain acts on that part', but now we can say which neurotransmitters are likely important - and as a result, infer the role of inhibitory neurons - in enabling us to stop unwanted thoughts," says professor Michael Anderson, from the University of Cambridge, who led the study.
"Our study suggests that if you could improve GABA activity within the hippocampus, this may help people to stop unwanted and intrusive thoughts," explain the researchers.
Of course, doing so is the difficult part—while GABA supplements do exist, clinical research on its effectiveness is sorely lacking, and they should only be taken after consulting your healthcare practitioner.
Schmitz TW, Correia MM, Ferreira CS, Prescot AP, Anderson MC. Hippocampal GABA Enables Inhibitory Control Over Unwanted Thoughts. Nat Commun. 2017;8(1):1311. doi:10.1038/s41467-017-00956-z