Also in the fear mix, according to Akiskal and Lara, a "robust body of evidence" supports GABA in the modulation of anxiety and fear. Other suspects include the BDNF receptor, the neuromodulator adenosine (caffeine blocks the A1 and A2 receptors), cortisol, and vasopressin.

Early life events and our environment also loom large, in essence nature interacting with nurture.

In short, it may be helpful to think of ourselves as wired for fear, egged on by our environment. As well as contributing to our illness symptoms and various behaviors, this primal emotion also interferes in our recovery, and probably had a lot to do with why so many of us remain “stuck” in our present half-lives.

But our human brains also come equipped with something other animals don’t have - self-awareness and the capacity to transcend what circumstances and nature handed us. Try tapping into this precious resource - don’t be afraid.