Are loneliness and social isolation associated with cognitive decline?

OBJECTIVE: This study aimed to examine the association of loneliness and social isolation on cognition over a 3-year follow-up period in middle- and older-aged adults. METHODS: Data from a Spanish nationally representative sample were analyzed (n = 1691; aged 50 years or older). Loneliness, social isolation, and cognition (immediate recall, delayed recall, verbal fluency, forward digit span, backward digit span, and a composite cognitive score) were assessed both at baseline and at follow-up. Adjusted generalized estimating equations models were performed. RESULTS: Loneliness was significantly associated with lower scores in the composite cognitive score, immediate and delayed recall, verbal fluency, and backward digit span (B = -0.14 to B = -3.16; P < .05) and with a more rapid decline from baseline to follow-up in two out of six cognitive tests. Higher social isolation was associated with lower scores in the composite cognitive score, verbal fluency, and forward digit span (B = -0.06 to B = -0.85; P < .05). The effect of loneliness and social isolation on cognition remained significant after the exclusion of individuals with depression. CONCLUSIONS: Both loneliness and social isolation are associated with decreased cognitive function over a 3-year follow-up period. The development of interventions that include the enhancement of social participation and the maintenance of emotionally supportive relationships might contribute to cognitive decline prevention and risk reduction.