目標：探討台灣65歲以上成人在過去十年間憂鬱症狀的趨勢變化，並評估性別在風險與保護因子上的差異。方法：本研究使用台灣2005年、2009年及2013年由國家衛生研究院執行的國民健康訪問調查資料（NHIS）的數據，分析了老年人的憂鬱症狀。這三項調查均為獨立的橫斷面調查。因此，本研究採用重複橫斷面設計，旨在檢視人群層面的趨勢，而非同一群體的縱向變化。共訪談了8,832名65歲以上的老年人。我們使用邏輯迴歸分析了症狀盛行率及相關因素的趨勢和性別差異。關鍵變數包括社會人口統計因素、慢性疾病和健康行為。分析遵循NHIS數據協議，並獲得IRB批准，並豁免知情同意。結果：老年人憂鬱症狀的盛行率從20.6%下降至13.3%（卡方值 = -7.5，p < 0.05）。對男性與女性皆具保護效果的因子包括：85歲以上的高齡、規律運動與較高的社會參與程度，但這些保護因子的效果在男女之間略有差異。碳水化合物攝取過多與憂鬱症狀相關，其中男性的風險（校正後勝算比 AOR = 8.8，95%信賴區間 = 5.1-15.2）高於女性（AOR = 7.9，95% CI = 5.2-11.8）。結論：本重複橫斷面研究辨識出台灣老年人憂鬱症狀的人群層級趨勢。儘管整體盛行率隨調查波次下降，但較低的憂鬱症狀主要出現在男性85歲以上與女性75歲以上的高齡族群，較可能反映選擇性存活與生命歷程中的（U型）年齡模式，而非年齡本身具有保護效果。跨所有調查波次，高碳水化合物飲食與跌倒均持續與較高的憂鬱症狀相關，而規律運動與社會參與則為穩健的保護因子。這些發現支持在台灣進行以族群為基礎的篩檢與標的性介入，以預防晚年憂鬱。

Objectives: To examine trends in depressive symptoms among adults aged 65+ in Taiwan over the past decade and assess gender differences in risk and protective factors. Methods: This study analyzed depressive symptoms among older adults using data from the 2005, 2009, and 2013 National Health Interview Surveys (NHIS) in Taiwan, which are three independent cross-sectional surveys. The study therefore adopted a repeated cross-sectional design to examine population-level trends rather than longitudinal changes within the same individuals. A total of 8,832 older adults (65+) were interviewed. Using logistic regression, we examined trends and gender differences in symptom prevalence and associated factors. Key variables included sociodemographic factors, chronic conditions, and health behaviors. Analyses adhered to NHIS data protocols and received IRB approval with a waiver of informed consent. Results: The prevalence of depressive symptoms among older adults declined from 20.6% to 13.3% (X2 = -7.5, p < 0.05). Protective factors for both genders included being 85+ years old, regular physical activity, and higher social participation, though these factors differed slightly between men and women. Carbohydrate-rich diets were linked to greater depressive symptoms, with a higher risk for men (AOR = 8.8, 95% CI = 5.1-15.2) compared to women (AOR = 7.9, 95% CI = 5.2-11.8). Conclusions: This repeated cross-sectional study identified population-level trends in depressive symptoms among older adults in Taiwan. Although overall prevalence declined across survey waves, lower depressive symptoms at advanced ages were mainly observed among men aged ≥ 85 and women aged ≥ 75, likely reflecting selective survival and life-course (U-shaped) patterns rather than a protective effect of aging per se. Across all waves, high-carbohydrate diets and falls were consistently associated with higher depressive symptoms, whereas regular exercise and social engagement were robust protective factors. These findings support targeted screening and population-based interventions to prevent late-life depression in Taiwan.

飲食；行為醫學；憂鬱症狀；老年人；健康促進

diet; behavioral medicine; depressive symptomatology; older adults; health promotion