LOS ANGELES, CA (Catholic Online) - These recent findings open up the prospect of developing a new fast-working type of anti-depressant.

A third of participants in the new study responded to the treatment within one hour and 20 minutes, seeing at least a 50 percent reduction in their symptoms. This was in comparison to a 15 percent reduction in those who took a placebo.

This was highly welcome as many of the patients in these trials had failed to improve in seven past antidepressant trials.

The one catch was that in spite of minimal side-effects, improvements were short-lived with patients finding relief for an average of only half an hour.

Medications typically used to treat depression work through the brain's serotonin system, building up levels of this "happy" hormone over a period of weeks.

The drug AZD6765 acts by preventing the binding of a brain chemical called glutamate to nerve cells.

It acts in a similar way to the Class C drug ketamine, but without the serious side-effects such as hallucinations.

Scientists at the National Institutes of Health, who conducted the study, said this could be because the new drug doesn't block glutamate binding as completely as ketamine.

Half of the 22 patients in the study received the drug through an IV drip, while the other half took a placebo. All of them completed a survey assessing their depressive state immediately after taking the drug and a few days after treatment. The two groups then switched the agent they took and went through the same assessment.

Patients reported only minor side effects, such as dizziness and nausea, when taking AZD6765, which were not significantly different from those experienced with the placebo.

"Our findings serve as a proof of concept that we can tap into an important component of the glutamate pathway to develop a new generation of safe, rapid-acting practical treatments for depression," research leader Dr. Carlos Zarate said.