Many of us may face the odd day of apathy, but what should we do when those listless feelings linger for weeks on end?

This month, I was moved to hear from a reader who fears he has lost his “zest”. “I would once wake up excited by the day ahead,” he tells us. “Now I fail to engage with anything.” It may feel hard to fight this emotional inertia, but the scientific literature offers some tips to nudge ourselves out of these ruts.

It is only…