I prefer explanations that fit observed behaviour - men take larger overdoses, and neither a propensity for violence nor a higher tolerance for messiness can explain that.

Likewise, I don't believe women become more violent or selfish as they reach middle age, yet they also start taking larger overdoses. It seems more likely there are specific problems that affect women at that point in their lives and/or they they feel less able to overcome problems they'd have coped with earlier (due to shrinking support networks, for example).

As for pain, I'd note that females are much more likely to self-harm than males (which, incidentally, is also messy).