People with anxiety sometimes encounter skeptics who insist that their mental condition is purely psychological, but new research shows that the brains of anxious people are fundamentally different than non-anxious brains.

A study published last month in Current Biology found that people who suffer from anxiety struggle to differentiate between neutral (or "safe") stimulus and those associated with threats. Essentially, that means that anxious people experience a behavioral phenomenon known as emotional over-generalization, failing to effectively differentiate emotional situations.

"We show that in patients with anxiety, emotional experience induces plasticity in brain circuits that lasts after the experience is over," Dr. Rony Paz, a study author and researcher at the Weizmann Institute of Science in Israel, said in a press release. "Such plastic changes occur in primary circuits that later mediate the response to new stimuli, resulting in an inability to discriminate between the originally experienced stimulus and a new similar stimulus."

In other words, the brains of people with anxiety fail to adapt to changing situations as effectively as people with non-anxious brains. Once their brain determines a "route" of how to react to a stimulus, that is the route that it continues to take, regardless of changing conditions. Paz continued:

"Therefore, anxiety patients respond emotionally to such new stimuli as well, resulting in anxiety even in apparently irrelevant new situations. Importantly, they cannot control this, as it is a perceptual inability to discriminate."

How the researchers arrived at this conclusion.

To test the brains of people with anxiety, researchers trained study participants to associate three tones (auditory stimuli) with money loss, money gain, or no consequence. Then these individuals were introduced to one of 15 new sounds and asked whether they recognized the tone from the first phase of the study. If they answered correctly, they were promised money.

The results? People with anxiety were more likely to mistake the new sounds with the first three tones, demonstrating how their brains perceive sounds (stimuli) linked to emotional experiences differently. It wasn't that their hearing or learning abilities are impaired; their brains are wired differently and don't differentiate between differences in stimuli.

"Anxiety traits can be completely normal, and even beneficial evolutionarily," Paz said. "Yet an emotional event, even minor sometimes, can induce brain changes that might lead to full-blown anxiety."

The researchers do not mention whether the brains of people with anxiety can be rewired to adapt to different emotional situations. However, previous research indicates that anxiety sufferers can benefit from exercise, meditation, therapy, and medication that can help them respond naturally to threats and neutral stimuli, Lifehacker reports.