Is depression in old age fatal only when people feel lonely?

The impact of depression and perceived loneliness in the oldest old is largely unknown. The authors studied the relationship between the presence of depressive symptoms and all-cause mortality in old age, especially the potential distorting effect of perceived loneliness.

Within a prospective population-based study of 85-year-olds, the 15-item Geriatric Depression Scale and the Loneliness Scale were annually applied in all 476 participants with a Mini-Mental State Examination score of 18 points or more.

Depression was present in 23% and associated with marital state, institutionalization, and perceived loneliness. When depression and perceived loneliness were assessed during follow-up, neither depression nor perceived loneliness had a significant effect on mortality. However, those who suffered from both depression and feelings of loneliness had a 2.1 times higher mortality risk.

The data suggest that the increased mortality risk attributable to depression in the presence of perceived loneliness may result from motivational depletion.