Depression: An antibiotic can help 2

Depression: An antibiotic can help

Examined Effectiveness: An Antibiotic for Treating Depression?

More and more people around the world suffer from depression. Mental illness is often treated with drugs (antidepressants). But they do not work for all patients. Patients can help with antibiotics.

The number of people with depression increases

According to the World Health Organization (WHO) report, the number of people with depression has increased considerably in recent years. More than 300 million people are affected worldwide – especially in modern industrial and service companies. And in the EU, more and more people are suffering from mental illnesses, especially in old age. According to estimates, one in four women and every eight in Germany suffer from depression once or even several times during their life.

Depression: An antibiotic can help 3
Not all patients with depression responded to the available medication. Maybe the antibiotic might help. (Picture: Africa Studio /

Not all patients answered the medication

In the treatment of depression, drugs (antidepressants) and psychotherapy are commonly used.

But drugs are far from helping all patients. This was also stated by Professor Isabella Heuser, Head of the Charité – Universitätsmedizin Berlin Department of Psychiatry and Psychotherapy at Benjamin Franklin Campus.

While effective and well-tolerated medications are available for moderate and severe depression. Unfortunately, approximately one third of patients are not responding to these medicines, "explains Freie Universität (FU) expert from Berlin.

For some people, the immune system is activated

As explained in communication, depression is caused by, for example, stress, problems of relationship, divorce or loss of close relative, physical-related illnesses.

So, apart from depression, sleeping problems, exhaustion, indifference, lack of appetite, loss of libido, and feelings of "autopilot" alone, the symptoms of depression include changes in hormone levels, which can, for example, cause menstruation to fail.

But that is not all. Now we know that some of the patients have an activated immune system. Even though there is no infection with bacteria, viruses or fungi, "explains Heuser.

An expert and several colleagues suspect that it affects exactly one-third of patients who are not helping with conventional antidepressant therapy.

However, it is still not clear what is the cause and effect of: Is the immune system triggering stress and causing depression? Or is it secreted by multiple stress hormones that stimulate the immune system?

It is well known that the response to stress and the immune response is closely interwoven.

Good results with antibiotics

"Although we can not yet demonstrate a pathophysiological chain of causality, this does not mean that we can not try to calm the pre-immune system," says Heuser, "with minocycline, proven and well-tolerated tetracycline antibiotics."

This drug not only acts antibacterial but also anti-inflammatory and neuroprotective, thus protecting nerve cells and fibers.

Minocycline, unlike most other antibiotics, can cross the blood-brain barrier that normally protects the brain from pathogens or substances circulating in the blood.

This is crucial in this case because the brain has its own immune system, which is also activated when the body secretes inflammatory and anti-inflammatory messengers, the so-called cytokines.

"From animal studies, we know that mice that are experimentally depressed have activated immune cells in the brain. After the use of minocycline, their activity is significantly reduced, says psychiatrist.

The Canadian study from 2017 showed a good anti-inflammatory effect on the brain of patients with multiple sclerosis (MS).

There are also pilot studies with depressed or bipolar subjects, which have also promised.

The drugs barely show any side effects

Isabella Heuser leads a double blind multicentre study to investigate the efficacy of minocycline depression in 160 subjects.

Neither the investigator nor the participant patient know who will receive the active substance and who will receive the placebo.

Along with FU Berlin, university hospitals were included in Aachen, Erlangen, Frankfurt, Göttingen, Munich and Regensburg, as well as the Max Planck Institute for Psychiatry in Munich.

As noted in the statement, minocycline has long been successfully used against acne and rheumatism and has several side effects.

But what happens in the brain when his immune system goes to barricades? "In certain parts of the brain, such as the lymphatic system that regulates our emotions, cytokines affect the effects of messengers such as dopamine, norepinephrine and acetylcholine," explains Heuser.

"It leads to change in behavior." Lymphatic system disorders, which are also responsible for the release of endogenous hormone (endorphins), are considered to be the cause of various diseases including posttraumatic stress disorder, autism and depression.

The drug may be approved for depression

People who are struggling with a real infection – like flu (flu) – also show a changed behavior: they feel lazy, with no energy, they have little appetite, they pull back and barely work.

Symptoms closely resembling symptoms of depression, in support of the theory of the relationship between depression and the activated immune system.

Subjects receive a constant dose of minocycline for six weeks, and then weekly about their benefit in depth.

After six months will be re-ordered. Before and after antibiotic therapy, they are faded and tested for all known cytokines.

"We hope we will eventually show that respondents who have these inflammatory markers reacted positively to the antibiotic," Heuser said.

Ideally, they even show a very specific cytokine pattern. If the minocycline meets expectations and will soon be approved as a cure for depression, this patient's blood sample – he hoped the professor would be – would be a sure sign of therapeutic success in advance.

Interested parties for ambulatory minocycline research can report to Veri Clemens by September 2019 (e-mail:

The precondition for participation is that the two previously completed attempts of antidepressant therapy with various drugs failed. The results of the study are expected in early 2020. (AD)


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