When researchers dig into the mental health histories of athletes, that’s exactly what they discover: the most perilous moment is when athletes face “injuries, career termination, decline in performance, or a catastrophic performance.” There’s always been a dim awareness of a post-glory-days slump, but it was written off as nothing more than an ego bruise, an overdue dose of humble pie for sports heroes now facing life as mere mortals. Instead, it could be something far deadlier: a dangerous chemical imbalance caused by a sudden drop in dopamine.