Washington, Nov 4 : Impulsive individuals behave aggressively, in part, because they have lower levels of GABA (gamma-aminobutyric acid), the most important inhibitory neurotransmitter, in a specific part of their brain involved in regulating self-control, according to a new study.

Impulsive individuals tend to display aggressive behaviour and have challenges ranging from drug and alcohol abuse, to problem gambling and difficult relationships.

They are less able to adapt to different social situations. Impulsivity is also a common feature of psychiatric disorders.

Dr. Frederic Boy, who led the research, explained the phenomenon by saying, "Advances in brain imaging techniques mean we are able to investigate different and specific areas of the human brain and see how they regulate people's behaviour."

"What is clear is that the way people behave results from a complex interaction between a number of genetic, social and environmental factors," he said.

The scientists studied males with no history of psychiatric disorders or substance dependence, who completed a questionnaire which helped assess different aspects of impulsivity, an important component of self-control.

They underwent a specialized magnetic resonance spectroscopy brain scan, an imaging technique that allows measurement of the amount of GABA in small regions of the brain.

The team found that men with more GABA in their dorsolateral prefrontal cortex had lower scores in one aspect of impulsivity called the "feeling of urgency", the tendency to act rashly in response to distress or other strong emotions and urges.

Inversely, men with lower GABA tended to have higher urgency ratings.

These findings have been published in the Biological Psychiatry. (ANI)