From The Other Significant Others by Rhaina Cohen.

“Having fewer close friends is associated with loneliness, and loneliness is linked to a variety pack of negative health outcomes, from high blood pressure to depression to cognitive decline. Compared to women who lose their husbands, men who lose their spouses experience a much more pronounced and long-lasting spike in loneliness and depression; they’re more likely than women to die by suicide. Researchers attribute these differences to women having more diverse systems of social support.”