Trajectories of cognitive decline before and after new-onset loneliness: The English Longitudinal Study of Ageing.

After the onset of loneliness, the rate of global cognitive decline was significantly faster in the loneliness group compared to the non-loneliness group.

• The rate of global cognitive decline was β: -0.010 standard deviation/year (95% CI: -0.015 to -0.005) faster in the loneliness group after onset.
• A linear mixed-effects model was used to analyze the trend of cognitive function changes over time before and after loneliness.
• Propensity score matching (PSM) was used to balance confounding factors between groups.
• Data were drawn from the English Longitudinal Study of Ageing (ELSA) database.

Before the onset of loneliness, there was no significant difference in the slope of cognitive decline between the loneliness group and the non-loneliness group.

• The absence of pre-onset differences suggests that cognitive decline did not precede or predict new-onset loneliness.
• This finding supports a directional relationship where loneliness onset leads to accelerated cognitive decline rather than cognitive decline leading to loneliness.
• The loneliness group and non-loneliness group had comparable cognitive trajectories prior to the loneliness event.

The study included participants from ELSA who were free of loneliness at baseline and had at least two recorded cognitive measures.

• Participants were required to have no loneliness at baseline and at least two recorded cognitive measures.
• The study used data from the English Longitudinal Study of Ageing (ELSA) database.
• Propensity score matching was applied to balance confounding factors between the loneliness and non-loneliness groups.

The onset of new-onset loneliness marks a critical inflection point associated with subsequent acceleration in cognitive decline.

• The authors describe the onset of loneliness as 'a critical inflection point' in cognitive trajectories.
• The finding supports the identification of new-onset loneliness as an indication to initiate more intensive cognitive monitoring.
• The change in cognitive trajectory occurred specifically after, and not before, the loneliness event, suggesting a temporally linked association.