Doxycycline is one of the most commonly prescribed antibiotics. It helps in the fight against acne, it fights infections of the upper respiratory tract, urinary system and digestive system. Recent research shows that this popular antibiotic can do much more. The authors of the work published in the journal Molecular Psychiatry argue that the drug can help people suffering from post-traumatic stress disorder.
Post-traumatic stress disorder (PTSD) is a term that covers a wide range of psychological symptoms that can develop in people who have stated or witnessed a traumatic event. This disorder is a form of response to an event so stressful that it exceeds a person’s ability to cope and adapt. Post-traumatic stress disorder usually affects people who have experienced war, terrorist attack, catastrophe, traffic accident, natural disaster, or have been victims of assault, rape, abduction, torture, and imprisonment in a concentration camp.
A person affected by PTSD suffers from anxiety, exhaustion, a sense of helplessness, haunted by memories of a traumatic event and nightmares related to the experienced trauma. Avoids situations that are associated with trauma (for example, after a car accident, he avoids driving a car). For some, the symptoms persist for years, leading to a permanent personality change.
As demonstrated by researchers from University College London and the University of Zurich, doxycycline interferes with the formation of negative associations related to traumatic experiences in the brain.
The research was carried out on a group of 76 healthy volunteers. During the first session, they were given either doxycycline or a placebo. Then they were shown blue or red on the computer screen 160 times (in random order) – displaying one of the colors was accompanied by electric shock in half of the cases.
One week later, the subjects were not given antibiotics or a placebo, but were shown the same colors. This time there was a loud noise instead of an electric shock. At the same time, scientists measured stress levels by registering blinking – a typical response to a sudden threat.
As it turned out, compared to the response of people receiving placebo, the anxiety response was 60 percent. weaker in people who were administered doxycycline in the first part of the experiment. This suggests that the drug significantly suppressed the formation of negatively pigmented memories. In contrast, other cognitive markers – such as sensory memory and attention levels – remained unchanged.
As the lead author of the research, prof. Dominik Bach from the University of Zurich, under the influence of the drug, the participants of the experiment did not forget that the electric shock appeared on the red screen. They “forgot” about the instinctive feeling of fear at the sight of the red screen.
How does doxycycline work? The antibiotic blocks the action of so-called matrix enzymes, which are involved in the formation of memories, even though they are outside the nerve cells. When these enzymes are overactive, it can cause some autoimmune diseases and cancer – doxycycline has already been used in their treatment.
According to the authors, doxycycline can both help in preventing post-traumatic stress and increase the effectiveness of its treatment with currently used methods.