Study antibiotic seems to work against posttraumatic stress disorder

Posttraumatic stress disorder avoidable by antibiotics?
Traumatic experiences often cause long-term psychological problems in the form of post-traumatic stress disorder (PTSD). This can not always be successfully remedied by psychotherapeutic treatment. New drug treatment options are therefore urgently sought. Surprisingly, taking an antibiotic could be helpful.

Scientists at the Psychiatric University Hospital and the University of Zurich have found in a recent study that the use of the antibiotic doxycycline may contribute to the prevention of post-traumatic stress disorder. After taking the drug, the study participants were much less reminiscent of an unpleasant event, according to the announcement of the University. The researchers have published the results of their study in the journal "Molecular Psychiatry".

Taking the antibiotic doxycycline to help prevent post-traumatic stress disorder. (Image: Osterland / fotolia.com)

Trauma memory medically influenced
Posttraumatic stress disorder can occur as a result of physical violence, war or even a natural disaster, with those experiencing the stressful event by suddenly einschießende memories or repeated nightmares again and again, reports the research team led by Professor Dominik Bach of the University of Zurich. Not always can this mental injury be successfully treated with psychotherapy. For a long time, therefore, a way has been sought to influence the trauma memory drug. However, the possibilities previously tested in animal models did not apply to humans or did not prove to be sufficiently effective.

Reminder of a negative experience significantly weakened
The researchers at the Psychiatric University Hospital and the University of Zurich have now successfully tested the use of a drug that significantly reduces the memory of a negative experience in humans. The scientists pursued a new approach in their investigations. She investigated how the inhibition of an important enzyme in memory formation affects traumatic memories. Because recently it was "known from laboratory experiments that for the formation of memory proteins from the space between nerve cells, the extracellular matrix, needed," explain the scientists. The antibiotic doxycycline inhibits the activity of these proteins.

Metalloproteinases inhibited by antibiotic
According to the researchers, the corresponding enzymes, so-called metalloproteinases, can be found throughout the body and play a role, for example, in the development of heart disease and various cancers. The antibiotic doxycycline inhibits the activity of these enzymes and has already been tested for the treatment of several of these diseases. The Zurich researchers have now tested how doxycycline affects memory formation. On the basis of almost 80 subjects, who were divided into an experimental and control group, the effect of the drug was checked.

Less startle reaction when taking doxycycline
In the experiments, the subjects received slightly painful electrical stimuli, which they learned to associate with a specific color, the researchers report. In addition, subjects in the experimental group previously received 200 milligrams of doxycycline, while participants in the control group took placebo. In the control group, the subjects showed, according to the researchers, even seven days later at the sight of the corresponding color an increased fright reactions. Here, the subjects of the experimental group showed a two-thirds weaker startle reaction, study director Dominik Bach. "This shows for the first time that doxycycline weakens the emotional memory when it is taken before a negative event," emphasizes the Zurich expert.

Doxycycline already applicable today
According to the researchers, the results show "that metalloproteinases can not only be used as tools in the laboratory, but are also relevant in humans for memory formation." According to the study leader, here are also important links to develop therapeutically active substances , In addition, "with current knowledge, doxycycline may be likely to be used to quench existing emotional memories - if patients so wish," explains Professor Bach. According to the researchers, "appropriate trauma memories are specifically activated in a psychotherapy and then weakened by the administration of doxycycline. (Fp)