Will We Someday Treat Mental Illness Before It Happens?
Most treatment for mental illness occurs after diagnosis. But what if there were a way to prevent the onset of mood disorders?
In a recent TedTalk, neuroscientist Rebecca Brachman discusses just this. At the moment there are no cures for mood disorders, only drugs which "suppress symptoms." She likens the distinction to a painkiller which treats an infection as compared to an antibiotic which cures it -- a painkiller will make you feel better, "but it will not treat that underlying disease." What this means is that most treatment for depression and PTSD will involve patients taking medication for the duration of their lives.
However, in the past few years, doctors have discovered a new antidepressant, the newest since the development of SSRIs (selective serotonin reuptake inhibitors). Calypsol, which is made from the medication ketamine, works very quickly, and unlike antidepressants, does not work on serotonin the brain -- it works on glutamate. Like many drugs, the discovery of ketamine as an antidepressant was kind of an accident, or the result of using the drug to treat a different, completely unrelated illness, or "repurposing." Ketamine was traditionally used as an anesthetic during surgery (and a recreational drug) and only recently has been "repurposed" as an antidepressant.
Calypsol seems to build resilience against stress, as stress is one of the factors or causes of depression, it might be useful as an anti-depressant. Brachman and her colleagues at Columbia University ran an experiment on mice, in which stressed mice were given a dosage of Calypsol. Brachman found that stressed mice are less likely to explore their surroundings and socialize with other mice; they prefer to stay in a corner behind a cup. The mice that had received a dose of Calypsol, however, were exploring and very social. They looked like they hadn't been stressed at all.
As Brachman says in her talk, while we do not know what causes depression, we do know that stress is a trigger in 80% of cases, especially in patients who have experienced trauma, such as active combat or natural disasters. Stress resilience is the ability to experience stress and bounce back and not develop depression, and with Calypsol, Brachman is hoping it might be possible to build up stress resliience in high-risk patients or populations. "Maybe we could enhance it [resilience], sort of akin to putting on armor," she said in the talk. Here's Brachman:
"So we're calling our resilience-enhancing drugs "paravaccines," which means vaccine-like, because it seems like they might have the potential to protect against stress and prevent mice from developing depression and post-traumatic stress disorder."