A hand-held breath ‘pacer’ has been developed to treat panic attacks — thought to affect as many as one million Britons, causing 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 U.S. 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.