Beta-blockers 'blot out memories' for sufferers with post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) affects around one in three of people caught up in such events, as the London bombings, and memories can be triggered just by a sound or smell.

A common blood pressure drug could help people who have witnessed traumatic events, to block out their distressing memories, and Cornell University psychiatrists are carrying out tests using beta-blockers.

The beta-blocker propranolol has been found to block the neurotransmitters involved in laying down memories.

People with PTSD are given counseling, but because it is not always effective, researchers have been looking for alternative therapies.

Studies have shown that rats who have learned to fear a tone followed by an electric shock, lose that fear if propranolol is administered after the tone starts.

Margaret Altemus, who is one of a team of psychiatrists at Cornell University working on the study, reports they are seeing similar results in early studies in humans.

Altemus, says if the memory of the event is associated with the fear, they always occur together.

The researchers plan to recruit 60 patients for a clinical trial where participants would be asked to take a dose of propranolol whenever they experienced symptoms of PTSD, such as an increased heart rate or breathing difficulties.

To date only one person has volunteered to take part.

Dr Altemus believes patients can be reluctant to try new therapies, and says a drug treatment could be a useful option for those with PTSD.

Berthold Gersons, based at the University of Amsterdam in the Netherlands, says it is a simple solution but they hope it will work.

But other psychiatrists have expressed concern about the use of the beta-blocker in PTSD treatment, and say PTSD is a natural response to traumatic events and should not be treated with drugs.

There are concerns that a drug which can alter memories could be misused, perhaps by the military who may want soldiers to become desensitized to violence.

The study is reported in the journal Nature.