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© UnknownDaily torture: But new scientific research could help those who suffer from regular anxiety attacks. (Posed by model)

Millions suffer from the daily torture of anxiety.

But help could be at hand after scientists identified a brain mechanism that makes individuals fearless.

More than one in four people are likely to experience a bout of anxiety at some point in their lives sufficiently intense to be classed as a psychiatric disorder.

The condition can severely damage quality of life, with some suffering regular panic attacks or almost constant 'nervous' symptoms such as sweating, raised heart rate and churning stomach.

Researchers at Stanford University in California found stimulating a brain circuit within a structure of grey matter could counter fear.

Tests on mice showed triggering the mechanism with pulses of light boosted their willingness to take risks - while inhibiting it rendered them more timid.

Psychiatrist Professor Karl Deisseroth said the finding opened the possibility of improved medications to help control anxiety disorders because the human brain is structured in the same way.

The team were able to pinpoint the phenomenon by working with a technology called optogenetics, where nerve cells are rendered photo-sensitive so their action can be turned on or off by different wavelengths of light.

They targeted a circuit within the amygdala region of the brain and found dramatic changes in the behaviour of mice.

Prof Deisseroth, whose research is published in Nature online, said: 'They suddenly became much more comfortable in situations they would ordinarily perceive as dangerous and, therefore, be quite anxious in.'

For example, rodents ordinarily try to avoid wide-open spaces such as fields because such places leave them exposed to predators.

But in simulations of both open and covered areas the willingness of mice to explore the open areas increased profoundly as soon as light was pulsed into the brain circuit.

Pulsing that same circuit with a different, inhibitory frequency of light produced the opposite result - the mice instantly became more anxious