New antidepressant delivers effect within hours, faster than any other drugs

A compound on a drug used to induce anaesthesia has been found to have the potential to be a new antidepressant that could rapidly treat depression. A new study shows the compound CGP3466B delivered effects to mice within hours instead of weeks or months that other existing antidepressants take.

CGP3466B is already proven safe and nontoxic for people. Neuroscientists at the Johns Hopkins Medicine found that the compound could lead to the development of a new class of fast-acting drugs as it targets a new network of proteins significant to treat depression.

Researchers believe that CGP3466B may be effective in patients who have been unresponsive to other types of antidepressant drugs. The study has been published in the journal Molecular Psychiatry.

The findings come from the analysis of the effect of the drug called ketamine that is long used at high doses to deliver anaesthesia during surgery. Ketamine is known to be a fast-acting antidepressant when delivered at lower doses, researchers said.

But they noted that ketamine can be addictive and can cause schizophrenia-like symptoms. The team focused on ketamine’s advantage of rapidly delivering antidepressant effects to patients.

Using biochemical tests on mouse nerve cells, the researchers examined the molecular chain reaction responsible for drug’s antidepressant effects. Results show that ketamine can stimulate the creation of proteins helping to build certain connections between nerve cells, which promote antidepressant effects.

The researchers then conducted two standard behavioural tests on mice to see if the compound CGP3466B present on ketamine could deliver same antidepressant effects in mammals alone.

In the first test, they analysed how quickly mice would give up on escaping from a pool of water. Those mice given with CGP3466B spent an average of extra half a minute to solve the problem.

In the second test, CGP3466B-treated mice appeared to be twice as fast to brave an unsheltered environment to get food. Researchers said the behaviours of mice observed in the two tests are considered non-depressed behaviours.

CGP3466B also worked in only half an hour in the second test to deliver positive effects, said researcher Dr Maged Harraz. "Other antidepressants tested in mice, like fluoxetine, can take three weeks to show similar results on the same test."

“CGP3466B works on the same network of proteins as ketamine, but since it works later in the chain reaction, it has fewer side effects," Harraz added. However, the researchers noted that further tests will take several more years before introducing the compound as an effective and safe antidepressant for people.