Researchers at the University of California-Berkeley have identified two different chinks in our brain circuitry that explain why some of us are more prone to anxiety.
Their findings may pave the way for more targeted treatment of chronic fear and anxiety disorders like panic attacks, social phobias, obsessive-compulsive behaviour, that affect at least 25 million Americans, the journal Neuron reports.
In the brain imaging study, researchers from Berkeley and Cambridge University discovered two distinct neural - nerve cell - pathways that play a role in whether we develop and overcome fears, according to a Berkeley statement.
The first involves an overactive amygdala, which houses the brain's primal fight-or-flight reflex and plays a role in developing specific phobias.
The second involves activity in the ventral prefrontal cortex, a neural region that helps us overcome our fears and worries.
Some participants were able to mobilize their ventral prefrontal cortex to reduce their fear responses even while negative events were still occurring, the study found.
"Some individuals with anxiety disorders are helped more by cognitive therapies, while others are helped more by drug treatments," said Berkeley psychologist Sonia Bishop, who led the study.
"If we know which of these neural vulnerabilities a patient has, we may be able to predict what treatment is most likely to be of help," she added.