Taking a common antibiotic doxycycline can help reduce negative thoughts and may provide a new approach to treat people suffering from posttraumatic stress disorder (PTSD), British and Swiss scientists have reported.
In a trial of 76 healthy volunteers, those given doxycycline had a 60% lower fear response than those who received a placebo dummy pill.
The team of researchers, co-led by Dominik Bach, a University of Zurich professor and a physician at the University Psychiatric Hospital, found that the antibiotic blocks certain proteins outside nerve cells, called matrix enzymes, which our brains need to form memories.
"We have demonstrated a proof-of-principle for an entirely new treatment strategy for PTSD," Bach told Reuters.
Lab experiments only recently revealed that proteins from the extracellular matrix, the space between nerve cells, are necessary for memory formation. Known as metalloproteinases, these enzymes are found throughout the body and involved in the development of heart disease and various cancer strains.
“Based on what we know today, though, doxycycline could probably already be used to dampen existing emotional memories – if patients so desire,” said Bach.
This treatment would involve specifically activating existing traumatic memories and weakening them by administering doxycycline. “We’re planning to test this combined therapy model first in healthy people and then in the clinic,” he added.
PTSD is caused by an overactive fear memory and includes a broad range of psychological symptoms that can develop after someone goes through a traumatic event.