Smoking ups anxiety, affects brain's ability to suppress fear

You may have to quit that ciggy, as a study has found that smoking cigarette may leave people more vulnerable to suffer from phobias and other types of chronic fear like post-traumatic stress disorder (PTSD).

Scientists have found that tobacco smoke can impair the brain`s ability to repress fear-related memories, leaving smokers less able to deal with fear and anxiety after a traumatic event.

It could have serious implications for people in jobs where they are most at risk of developing PTSD, such as in the armed forces. Around 33 percent of soldiers are believed to smoke.

The scientists behind the study believe chemicals in tobacco may interfere with the messages between neurons in the brain - also known as neurotransmitters - that are involved in controlling fear.

Lead researcher Dr Jan Haaker from the University Medical Centre in Hamburg, Germany said that interventions against smoking in PTSD patients could help them recover.Haaker added that early interventions to stop smoking in people at risk - such as soldiers in combat, firefighters and police officers - might also reduce the risk of developing anxiety-related disorders.`

This might play a role in phobias as well. These occur due to fear conditioning, where a fear response is connected to an associated memory to connect an event with something in the environment.

The team examined the fear responses in 376 healthy volunteers, a fifth of them were regular smokers.They also asked the participants to rate their stress, fear and tension during the tests.

They found that smokers tended to have a larger fear response to the symbols after they had been taught to associate them with electric shocks than the non-smokers.Dr Haaker said the more people seemed to smoke, the less able they were to inhibit their fear response.

The results suggest that smoking impairs the repression of fear related memories, particularly when no danger is present.The results indicated that the more and longer people have smoked for, the higher the deficit in inhibiting fear responses.

The researchers noted that smoking changes neurotransmitter balances in the brain, which are necessary for successful safety learning.