Japan: a new nasal spray to fight depression

Japan: a new nasal spray to fight depression


Recently, Japanese researchers have developed a non-invasive treatment to treat the physiological effects of depression. The nasal spray in itself is nothing new, but it still represents a real innovation.

A non-invasive method

In medicine, nasal sprays are quite common and research continues. In 2020, American researchers created a vaccine against the SARS-CoV-2 coronavirus in the form of a nasal spray. In addition, in 2018, other scientists had presented a nasal spray to fight against gambling addiction. Now, there is talk of a spray to fight against depression, as indicated in a publication in the Journal of Controlled Release in July 2021. Researchers from the Tokyo University of Sciences (Japan) indeed indicate that their spray is capable of treating depression in just twenty minutes.

It should be remembered that medicine currently uses very invasive intracerebroventricular injections (ICV), and therefore not without risk, because until then doctors have not been able to route the molecules directly to the brain. Nevertheless, the spray of Japanese researchers would be able to do so.

An improvement in physiological signs

Previous research on the subject has attempted to transfer molecules via the olfactory epithelium, a tissue essential for smell. However, this tissue represents only 2% of the nasal mucosa. Thus, Japanese researchers focused their work on the respiratory epithelium, which represents the rest of the nasal mucosa. They also knew that the GLP-2 peptide took on a role of messenger between the tissues and therefore focused their attention on the latter. During the experiment, the aim was to prevent the breakdown of GLP-2 so that it could pass into the respiratory epithelium without hindrance and eventually reach the brain.

Mice were used in the experiment because they can have depressive disorders quite similar to humans. However, the results have been very encouraging. After spraying, improvement in physiological signs of depression occurred only after about 20 minutes. On the other hand, it is only a question of behavioral improvement, not an improvement in psychological or mental state.

Researchers believe that this experience may open the doors to new avenues of treatment for depression. It is also possible that sprays may emerge to fight other diseases such as Alzheimer’s. Finally, remember that in 2019, the FDA in the United States was about to authorize the development of an esketamine-based nasal spray to fight depression.