A hand-held breath 'pacer' has been developed to treat panic attacks, which cause symptoms such as a fast heartbeat, chest pain, feeling faint and shortness of breath.
The device, which looks like an inhaler, is being tested in two clinical trials in the United States with patients who suffer from panic attacks or who have had heart attacks (which can lead to raised levels of anxiety).
Current treatments for panic attacks include counselling and medication -usually selective serotonin reuptake inhibitor (SSRI) antidepressants or an anti-epilepsy drug such as pregabalin, which is thought to work by reducing the levels of the brain chemical glutamate (in turn, linked to anxiety).
But the potential side-effects have driven a search for drug-free treatments.
The new approach is based on the understanding about how our bodies respond to stress and life-endangering events.
When we feel threatened, our sympathetic nervous system kicks in, releasing energy to prepare the body for action. This boosts the heart rate, and extra blood is sent to the muscles.
As part of this fight or flight response, breathing becomes faster and more shallow, so more oxygen can be taken in for fighting or running.
Once the danger is over, the parasympathetic nervous system takes over to restore normality.
But in panic attacks and acute stress, the body remains in alert mode. This causes a rush of intense mental and physical symptoms.
People who have suffered a heart attack can experience similar symptoms (anxiety about whether their pacemaker is working is particularly common, according to the British Heart Foundation).
The new treatment slows breathing down to normal rates. Breathing exercises are recommended by the NHS for both anxiety and stress, but one of the challenges is getting it right when panic, anxiety and stress levels are peaking.
The battery-powered device, the shape and size of an inhaler used by asthma patients, is first calibrated to the normal breathing patterns of the individual - to do this, the user breathes out into the mouthpiece and inhales through the nose, several times.
During a panic attack or when anxious or stressed, the user breathes out into the device and does not stop until the last of a series of three lights comes on.
They then take a breath and breathe into the device again - the process is repeated for around three minutes.
The device can also deliver scents (such as lavender) associated with relaxation.
In a trial at Lenox Hill Hospital, New York, 35 patients with panic disorders are being treated with the device.
"There are limited options in the management of anxiety and panic attack symptoms," say the researchers.
"Our hypothesis is that it will provide a drug-free, early intervention, and long-term treatment option that will improve patients' anxiety and panic attack symptoms."
In a second trial, at the Mayo Clinic, Minnesota, it's being used for stress management in 100 heart attack patients. All will have the usual care for heart attack, while half will also get the device to use once a day for 12 weeks.
Sir Cary Cooper, a professor of psychology and health at Manchester University, said: "Anxiety symptoms, such as breathlessness, are the same whatever the cause, whether it is general anxiety, or worrying about whether your pacemaker will work.
"This device seems to be a really good idea but it should be used alongside talking therapy and other treatments."
© Daily Mail