Kraav SL, Awoyemi O, Junttila N, et al. - Researchers here examined how loneliness, social isolation, and mortality are associated. In addition, they sought possible mechanisms underlying these associations. Data from a prospective population-based cohort of Finnish men (42–61 years at baseline, n = 2,588) followed up for an average of 23.2 years were analyzed. The national population register was assessed for obtaining mortality for 2012. An increase in the risk of all-cause mortality was observed in correlation with both loneliness and social isolation. Except after adjustments for lifestyle variables or Human Population Laboratory (HPL) depression scores, loneliness was predictive of cancer mortality. Loneliness was also predictive of cardiovascular disease (CVD) mortality, except after adjustments for HPL depression scores. All-cause mortality and injury mortality was predicted by social isolation. Loneliness and HPL depression scores were identified as mediating the effect of social isolation on all-cause mortality.