Scientists have developed a new class of antidepressants that appear to work much faster than current treatments for depression.
The drug has so far only been tested on the brains of mice, but the new research could eventually pave the way for a new, fast-acting antidepressant.
The most commonly prescribed antidepressants, such as selective serotonin reuptake inhibitors (SSRIs), target the serotonin transporter.
Serotonin is a multifaceted neurotransmitter that is involved in a number of complex biological functions, including mood, cognition, reward, learning, and memory. The serotonin transporter is like a pump that takes up serotonin from the gaps between neurons after it has been activated, he explains IFL Science.
By targeting this process, drugs can increase serotonin levels in the brain and produce an antidepressant effect. For example, SSRIs work by blocking reuptake, meaning that serotonin remains in the space between neurons and remains available to transmit additional signals.
A new class of antidepressants could be much better than current treatments
The new class of antidepressants also targets the serotonin transporter but avoids some of the problems seen with SSRIs.
Called ZZL-7, the small compound was found to help regulate the firing of serotonin-producing neurons in the dorsal raphe nucleus, a part of the brainstem that creates much of the serotonin for the rest of the central nervous system.
The compound works by disrupting the interaction between the serotonin transporter and an enzyme called neuronal nitric oxide synthase (nNOS).
Scientists at Nanjing Medical University in China found that disconnecting the serotonin transporter from nNOS in the brains of mice reduced intracellular serotonin in the dorsal raphe nucleus, which dramatically increased serotonin release in the medial prefrontal cortex.
SSRIs (including fluoxetine, citalopram, paroxetine, and sertraline) work well for many people with major depressive disorder and other mental health problems. However, they are far from perfect. First, there are doubts about how effective they are in improving quality of life in the long term.
They can also take weeks to produce effects and come with a nasty list of side effects, including an increased risk of suicide. From what can be concluded so far, it seems that ZZL-7 would take action significantly faster than SSRIs, at least when it comes to mice.
The study authors explained that the compound “caused an antidepressant effect 2 hours after treatment without unwanted side effects.”
The medicine will not arrive in pharmacies any time soon
But this treatment has only been tested on mice so far. The path that new drugs take from animal studies to pharmacy shelves is long and often laborious. So even if this class of antidepressant ticks all the boxes, proving to be safe and effective in humans, it will be many years before it is prescribed.
Even so, the research offers some hope for the millions of people around the world who struggle with depression. According to the CDC, depression affects about 16 million American adults each year, and about 1 in 6 adults will experience depression at some point in their lives.
The new study was published in magazine Science.