目標：分析我國中老年人的社會參與及社會支持對寂寞感及憂鬱情形發生的影響。方法：為回溯性世代追蹤研究，資料來源為2015與2019年中老年身心社會生活狀況長期追蹤調查資料，研究對象為50歲以上中老年人，以廣義估計方程式分析，控制基線社會人口學特質、健康情形與行為、個人經驗與居住地區特質後，分析社會參與（擔任志工經驗、社團或活動參與）及社會支持（情緒支持及訊息支持）對寂寞感與憂鬱情形發生之影響。結果：共3,967人納入分析，相較於無社會參與，有志工經驗的中老年人發生寂寞感的機率為0.81倍，參與社會團體幹部者則是0.73倍，僅參與社會團體者發生憂鬱情形的機率為0.58倍；相較於低社會支持者，中訊息與高訊息支持者其發生寂寞感的風險分別為0.80倍與0.63倍，高訊息支持者的憂鬱情形發生風險則為0.79倍。結論：社會支持有助於減少中老年人寂寞感及憂鬱情形，而社會參與則有助於降低中老年人的寂寞感發生，未來政策應考慮多元方案的介入，以增進社會支持強度。

Objectives: This retrospective cohort study explored the effects of social participation and social support on loneliness and depression in middle-aged and older individuals. Methods: The study cohort comprised participants aged ≥50 years from the Taiwan Longitudinal Study in Aging. Generalized estimating equations were used to analyze the effects of social participation (volunteer experience and involvement in a guild or association) and social support (emotional support and informational support) on loneliness and depression. Statistical models were adjusted for baseline area characteristics. Results: This study included 3,967 participants. Individuals with volunteer experience and those serving as social group leaders had 0.81- and 0.73-fold lower risks of loneliness, respectively, than did individuals with no social participation experience. Furthermore, individuals who only participated in social groups had a 0.58-fold lower risk of depression. Individuals with middle informational support and those with high informational support had 0.80- and 0.63-fold lower risks of loneliness, respectively, than individuals with low social support. The risk of depression was 0.79-fold lower in individuals with high informational support than in those with low informational support. Conclusions: This study suggests that social support reduces loneliness and depression in middle-aged and older adults, whereas social participation reduces loneliness. Health promotion policies should incorporate pluralistic interventions aimed at enhancing social support.

中老年人；寂寞感；憂鬱情形；社會參與；社會支持

middle-aged and elderly individuals; loneliness; depression; social participation; social support