People with anger disorder wired to misunderstand social cues

People with anger issues are wired to misunderstand the intentions of others in social situations which cause impaired judgement and escalates explosive outbursts, a new study has found.

Scientists found that people with intermittent explosive disorder (IED), or impulsive aggression, have a weakened connection between regions of the brain associated with sensory input, language processing and social interaction.

People with anger issues tend think others are being hostile when they are not and make the wrong conclusions about their intentions, researchers said.

They also do not take in all the data from a social interaction, such as body language or certain words, and notice only those things that reinforce their belief that the other person is challenging them.

Decreased connectivity between regions of the brain that process a social situation could lead to the impaired judgement that escalates to an explosive outburst of anger.

Researchers from the University of Chicago show that white matter in a region of the brain called the superior longitudinal fasciculus (SLF) has less integrity and density in people with IED than in healthy individuals and those with other psychiatric disorders.

The SLF connects the brain's frontal lobe - responsible for decision-making, emotion and understanding consequences of actions - with the parietal lobe, which processes language and sensory input.

"It's like an information superhighway connecting the frontal cortex to the parietal lobes," said Royce Lee, associate professor at the University of Chicago.

"We think that points to social cognition as an important area to think about for people with anger problems," Lee said.

Researchers used diffusion tensor imaging, a form of magnetic resonance imaging (MRI) that measures the volume and density of white matter connective tissue in the brain.
Connectivity is a critical issue because the brains of people with psychiatric disorders usually show very few physical differences from healthy individuals.

"It's not so much how the brain is structured, but the way these regions are connected to each other," Lee said.

"That might be where we're going to see a lot of the problems in psychiatric disorders, so white matter is a natural place to start since that's the brain's natural wiring from one region to another," he said.

"This is another example of tangible deficits in the brains of those with IED that indicate that impulsive aggressive behaviour is not simply 'bad behaviour' but behaviour with a real biological basis that can be studied and treated," said Emil Coccaro, professor at the University of Chicago.