Social Networks and Longitudinal Neuropsychiatric Symptom Trajectories across the Cognitive Continuum

Neuropsychiatric symptoms (NPSs) significantly contribute to caregiver burden and the risk of institutionalization in patients with cognitive dysfunction. Although social isolation is linked to cognitive decline, its associations with longitudinal NPS trajectories are poorly understood. This study explores the association between social network characteristics and longitudinal NPS trajectories across the cognitive continuum.

We conducted a retrospective observational study of 618 adults (aged ≥ 50) evaluated at a memory clinic between 2017 and 2024. Social networks were assessed, and NPS were measured using the Neuropsychiatric Inventory (NPI). Linear mixed-effects models examined associations between social networks and NPI trajectories, adjusting for demographics, comorbidities, medications, and cognitive status.

At baseline, 485 (78.5%) participants had an adequate social network. A cross-sectional multivariable analysis showed that an adequate social network was independently associated with lower NPI scores (β = -1.716, p = 0.029). Longitudinally, adequate social networks were associated with lower NPI scores (β = -2.156, p = 0.008), though the time × social network interaction was not significant overall (p > 0.05). However, a subgroup analysis revealed a significant interaction (β = -0.124, p < 0.001) in participants without baseline NPS. No significant interactions were observed by cognitive status (p > 0.05).

Social networks are associated with the cross-sectional NPS burden and predict longitudinal symptom trajectories. These findings suggest that social network characteristics could be a modifiable target for attenuating the risk of NPS emergence.