Scientists at the University of Cambridge have identified the chemical responsible for suppressing unwanted thoughts.The discovery somehow explains the unusual persistence of negative thoughts in people with schizophrenia, post-traumatic stress disorder, and other mental conditions.

Key to Suppressing Unwanted Thoughts

Sometimes, we are reminded of the things we had done in the past, and these can be both good and bad memories.Memories and thoughts of the past may be easy to deal with if we are in a positive mood.But, it can be a great challenge if the memory is traumatic and the mood is negative.Dark thoughts will take the person back to that event, reliving it in the mind.

"Our ability to control our thoughts is fundamental to our well-being.When this capacity breaks down, it causes some of the most debilitating symptoms of psychiatric diseases: intrusive memories, images, hallucinations, ruminations, and pathological and persistent worries.These are all key symptoms of mental illnesses such as PTSD, schizophrenia, depression, and anxiety," said Michael Anderson from the Medical Research Council Cognition and Brain Sciences at Cambridge University.

The brain area called the prefrontal cortex is responsible for controlling our actions and, according to recent discoveries, is capable of stopping our thoughts.The prefrontal cortex is the master of many regions in the brain such as the motor cortex which is responsible for action and movements and the hippocampus responsible for memories.In the study, the scientists tasked the participants with Think/No-Think to find the relevant brain process that triggers the prefrontal cortex to suppress thoughts.

During the first part of the task, the participants learned to associate a series of words with a paired but unrelated word, such as spoon/rift and phone/cap.In the second part of the task, the participants were asked to remember the associated word if the cue came out green or suppress it if the cue came out red.It means that if they saw the word "phone" in red, participants should only stare at the word but stop from thinking about the associated word "cap."

The scientists used combined technologies of the functional magnetic resonance imaging and magnetic resonance electroscopy.Using these imaging devices, they were able to know what was happening in brain regions of the participants during the task.The key chemical that helped the brain suppress unwanted thoughts is the GABA or gamma-aminobutyric acid.

Gamma-Aminobutyric Acid

Before the study, GABA was known as the neurotransmitter that blocks impulses between the nerve and cells in the brain.Lower levels of GABA may lead to mood problems, epilepsy, and chronic pain, while elevated levels of the neurotransmitter improve mood, relieve anxiety, and help with attention deficit hyperactivity disorder.GABA is not naturally found in foods, but a variety of foods contain flavonoids which are substances that may influence the GABA activity in the brain.Fruits, vegetables, teas, and red wine have flavonoids that may help GABA functionality.

In the study, the scientists found that GABA released by a single nerve cell can suppress activity in other cells connected to it.They also discovered that the concentration of the neurotransmitter is in the hippocampus.The hippocampus with GABA gives a person the ability to block the recall process of negative and unwanted memories and thoughts.

The scientific team was surprised that the study showed the specific location, the chemical involved, and the process on how the brain managed the exchange of thoughts in the mind.

1.People with less GABA in their hippocampus were less capable of suppressing unwanted thoughts.

2.People with less GABA in their hippocampus displayed hyperactivity in their brain.

3.Less GABA means an elevated activity of the hippocampus.

4.Less GABA means the limited capability of inhibiting intrusive memory and thoughts.Excessive negative thoughts can lead to worrying and rumination.

5.Uncontrolled, elevated activity of the hippocampus may indicate conditions such as PTSD, and anxiety and chronic depression.

The study suggested that improvements on the GABA activity within the hippocampus may help people stop intrusive, negative, and unwanted thoughts.The suggestion may help people suffering from chronic anxiety, fear, depression, and worry issues.

Global Trends: PTSD, Depression, Schizophrenia

- About 6.8 percent of Americans have a lifetime prevalence of PTSD.The lifetime prevalence of PTSD in men was 3.6 percent and 9.7 percent in women.

- Global PTSD lifetime prevalence ranges from 0.3 percent to 6.1 percent based on 27 countries in 2008, according to the World Health Organization.

- There is no population-based epidemiological study of PTSD in children.

- About 300 million people of all ages suffer from depression.

- Depression is a common mental disorder and it can lead to suicide.

- Depression is a leading cause of many disabilities and diseases around the globe.

- More than 21 million people suffer from the schizophrenia, a severe mental disorder.

- Schizophrenics are most likely to die quicker than normal people because of vulnerability to cardiovascular problems, infectious diseases, and metabolic disorders.

- More than 50 percent of schizophrenics do not receive treatment and about 90 percent of untreated schizophrenics live in low-income and middle-income nations.