How does your brain stop unwanted thoughts?

Control over intrusive thoughts is crucial for your psychological well-being

Everybody knows those nagging, intrusive thoughts like “Why on earth did I make that stupid comment?” or “What if I have cancer?”. They are not only annoying, it also feels like they get worse the more we engage in them. At times, it can feel difficult to manage these thoughts and the sooner the brain manages to shut them off, the better.

The cognitive process responsible for this is called inhibitory control. The brain area most associated with inhibitory control is the prefrontal cortex, the executive behavioral control panel of the brain. It allows us to inhibit impulses, control our behavior and make deliberate decisions.

While everybody knows nagging thoughts and struggles with a lack of cognitive control at times, this is even more pronounced in individuals with certain psychiatric conditions. For example, somebody suffering from schizophrenia might be unable to let go of a hallucination. Meanwhile, a depressed person might keep ruminating about their depressive symptoms, analyzing the reasons for their sadness. Interestingly, depressive rumination is elevated in women relative to men, which also accounts for the higher depression rates.


Hyperactivity of the hippocampus could be the reason for poor cognitive control in psychiatric conditions

The lack of cognitive control in post-traumatic stress disorder, schizophrenia, major depression or anxiety is most commonly associated with reduced engagement of the lateral prefrontal cortex. However, it is often overlooked that those disorders also share another feature in brain physiology: hyperactivity of the hippocampus. The hippocampus is a brain area that is highly involved in storing memory and it is connected to the prefrontal cortex. When we consciously try to control thoughts and memories, the prefrontal cortex is giving the commands – yet, it is the job of the hippocampus to access or inhibit the memories.

That is why a recent study published in Nature Communications looked at the role of hippocampal activity in cognitive control. They have identified the role of one specific neurotransmitter being the game changer here: Gamma-Aminobutyric acid (GABA) might be the key to consciously control your unwanted thoughts.

GABA – The neurotransmitter that is responsible for a calmer mind

Neurotransmitters are the “chemical messengers” of the brain, sending signals from one neuron to another. Hereby, they can either act excitatory or inhibitory. Dopamine, serotonin or glutamate are the most known. But altogether there are more than 100 different kinds of neurotransmitters.

GABA is a neurotransmitter which has a strong inhibiting function, regulating the electrical activity of the surrounding neurons. This neurotransmitter is responsible for your good night’s sleep, reduces anxiety and is involved in memory formation. It calms the brain down, so to speak.

In the abovementioned study, healthy participants were instructed to suppress their thoughts. While watching word pairs as cues, they had to either actively recall memories for these cues or avoid recalling memories and “push them out of their mind” (Think/No-Think paradigm). At the same time, brain images of the participants were taken using functional magnetic resonance imaging (fMRI). A process that allows researchers to visualize which brain areas are being activated throughout a task. To assess whether GABAergic inhibition was more pronounced in the No-Think condition, they measured brain activity and concentration of GABA in the hippocampus. After finishing the task subjects’ memory was tested.

The authors found that suppression of thoughts resulted in worse memory of the word pairs and reduced activity in the hippocampus. Furthermore, higher concentrations of hippocampal GABA predicted higher forgetting of the thoughts that participants tried to suppress in the No-Think condition. Moreover, it predicted a better ability of the prefrontal cortex to control the memory retrieval processes of the hippocampus.

This indicates that the GABAergic inhibition process in the hippocampus may be crucial for implementing the orders of the prefrontal cortex and thereby suppressing unwanted information. Interestingly, this mechanism is specific for suppressing thoughts, but not actions.

Reduced concentrations of GABA in the hippocampus might be the reason for persistent intrusive thoughts and hallucinations

“What’s exciting about this is that now we’re getting very specific”, said Michael Anderson, one of the authors of the study, in an interview with the BBC. “Before, we could only say ‘this part of the brain acts on that part’, but now we can say which neurotransmitters are likely to be important.”

The authors demonstrate that it is not enough to only focus on the efficient functioning of the prefrontal cortex. Instead, the hippocampus and hippocampal GABA concentration play a major role in suppressing unwanted thoughts, as well. If the concentration of GABA in the hippocampus is not high enough, the conscious inhibition process might actually not work out.




While this particular study examined the role of GABA in healthy individuals, we also know that an impaired GABAergic inhibition process of the hippocampus is a common symptom in many psychiatric conditions. For instance, this could be a plausible explanation for persistent intrusive thoughts and reoccurring hallucinations in schizophrenia.

Although this study does not explore treatment options, it suggests that improving GABA concentration in the hippocampus plays an important role, because it gives your brain the instruments to enable conscious control over unwanted thoughts.

Mindfulness practice improves GABA levels in your brain and reduces pain and everyday anxiety

Luckily, natural ways exist to increase the concentration of GABA in your brain: Mindfulness training like meditation and yoga were shown to heighten the levels of GABA. In other words, through mindfulness training you can improve the brain mechanism responsible for suppressing unwanted thoughts.

Mindfulness meditation specifically is a cognitive practice, where you try to keep a sustained non-judgmental awareness of arising sensory events. Think of a Buddhist monk, sitting in silence and observing his own thoughts. Just being present. Wouldn’t you also enjoy that kind of calmness once in a while?

Research showed that after only three mindfulness training sessions pain and everyday anxiety was reduced in healthy individuals. Therefore, mindfulness training might also be a good therapy option in many psychiatric conditions. And in fact, some well-established programs already exist. Mindfulness-Based Stress Reduction (MBSR), developed by Jon Kabat-Zinn, has proven efficient in “major and clinically relevant reductions in medical and psychological symptoms across a wide range of medical diagnosis, including many different chronic pain conditions, other medical diagnosis and in medical patients with a secondary diagnosis of anxiety and/or panic”. The intervention lasts for eight weeks and includes mindfulness meditation, breathing exercises and yoga. It also teaches non-judgmental awareness in everyday life.




Start meditating to gain control over unwanted thoughts

But even if you are healthy, mindfulness training might improve the quality of your everyday life. As Kate Pickert puts it in her TIME article “if distraction is the pre-eminent condition of our age, then mindfulness, in the eyes of enthusiasts, is the most logical response.”

There are many ways to get you started. If you want to give it a try, have a look at this five-step guide. Furthermore, there are a lot of commercial apps on the market, but there are also non-profits like the Smiling Mind program, founded by an Australian organization. They aim to bring mindfulness training to the classroom and the workplace. There is an app, but they also train educators, providing knowledge and materials on how to include mindfulness in the curriculum.
Mindfulness practice provides a lot of benefits, even for a healthy mind. Big companies like Google, Nike and Apple have their own mindfulness training programs for employees. So why not give it a try? All it requires is a little time and practice. A calmer mind will help you focus on what is important in life. And just consider finally gaining control over those unwanted thoughts!

One thought on “How does your brain stop unwanted thoughts?

  1. I find this interesting as I have been diagnosed with schizophrenia and depression. They tried all types of drugs on me which did not do much even threatened ECT. I found running yoga and mindfulness and medatation about the only thing useful. I find it encouraging that people are taking this stuff seriously.

    Liked by 2 people

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