It's obvious why we are generally concerned in athletes' minds only when a desperate situation like Lennon's occurs. The disconnect is clear between what we can see - young people who have reached the peak of physical fitness - and what we can't.
But players like Lennon are far from alone, no matter the code, and more attention must be paid to mental health among athletes at every level.
Sport is often triumphant, providing its participants with exuberant highs like no other profession. Sport can also be crushing, cold and lonesome.
Sometimes, athletes' mental health aligns with their physical fitness. Chiefs midfielder Charlie Ngatai, who will tonight end a year-long absence through concussion, fell into depression during his spell outside of sport, while Lennon has also been stuck on the sidelines since February with a muscle strain.
Other times, there is no link between the two. Former Black Caps bowler Iain O'Brien was but one cricketer who suffered in lengthy stretches on the road, finding himself a stranger in a strange land whose athletic ability offered no solace once isolated in a hotel room.
The point being, mental health issues strike different people in diverse scenarios. The demons that can take residence inside an athlete's head pay no respect to sporting accomplishments, offer no respite to one group over another.
And because it's a problem that doesn't discriminate, it's undetectable unless an athlete offers testimony of their own, whether through an emotional admission or an extreme action like Lennon's.
Unfortunately, the latter is more common than the former. And for that, we have to question the culture that continues to permeate sport, a culture that still asks athletes to bottle up feelings of ostensible weakness.
Where we can all see a footballer limping after a heavy challenge, no one can spot those struggling in their own mind. Where we all understand an athlete absent with ruptured ligaments, we're too few in accepting those with afflictions incurable by a surgeon's knife.
It's not all our fault; the stigma exists within sport. Men aren't men, the common thinking goes, if they are beset with the blues because of an injury, or if they become despondent for really no reason at all.
Who knows what caused Lennon to go near that motorway? It was shocking - a rich and prosperous young man taking such an action - but it should not be surprising.
Not any more, not if we want more athletes to readily acknowledge their ills. Professional sport can be as unforgiving as any livelihood, so we would be wise to be more forgiving to those in need.
