本研究旨在探討嗅吸式芳香療法對機構高齡者憂鬱情緒與睡眠品質之影響，採用隨機對照之前、後測實驗設計，於北部某老人住宅招募96位年滿65歲以上之高齡住民，依隨機方式分配至實驗上午組、實驗下午組與對照組。實驗組介入為每日佩戴一次「口罩薰香扣」進行嗅吸式芳香療法，持續時間約1小時，共4週，精油配方為薰衣草、甜橙與佛手柑之複方精油。研究工具包含簡式老人憂鬱量表（Geriatric Depression Scale– ShortForm, GDS-SF）與匹茲堡睡眠品質指數（Pittsburgh Sleep Quality Index, PSQI）。結果顯示，實驗上午組與實驗下午組在介入後憂鬱情緒有下降情形（p < .05），但在控制性別、年齡與教育程度等共變項後三組並無達到統計上顯著差異；睡眠品質得分雖在單純的前、後測比較上未達顯著差異，有下降趨勢，但未達統計上顯著差異。研究支持嗅吸式芳香療法為安全、操作簡便且具潛力之非藥物介入模式，特別適用於機構內高齡者情緒照護之應用，建議未來可結合客觀生理指標與長期追蹤以驗證其持續成效與介入機制。PSQI分數下降幅度約在1分，但進一步的重複量數共變數分析顯示，組別之間的差異達統計顯著，且效果量（Partial η2 = 0.19）屬於大效應，顯示芳香療法介入對睡眠品質具有實際臨床意義，此結果支持芳香療法在高齡族群的應用價值。

This study aimed to examine the effects of inhaled aromatherapy on depressive symptoms and sleep quality among institutionalized older adults. A randomized controlled pre-test/post-test experimental design was adopted. A total of 96 residents aged 65 years and older were recruited from a residential care facility in northern Taiwan and randomly assigned to a morning experimental group, an afternoon experimental group, or a control group. Participants in the experimental groups received inhaled aromatherapy by wearing a “mask aroma clip” once daily for approximately 1 hour over a 4-week period. The essential oil blend consisted of lavender, sweet orange, and bergamot. Research instruments included the Geriatric Depression Scale– Short Form (GDS-SF) and the Pittsburgh Sleep Quality Index (PSQI). The results indicated that depressive symptoms decreased in both experimental groups after the intervention ( p < .05). However, after controlling for covariates such as gender, age, and education level, no statistically significant differences were observed among the three groups. Regarding sleep quality, although the pre-post comparison showed a decreasing trend in PSQI scores, the change did not reach statistical significance. The study supports inhaled aromatherapy as a safe, easy-to- administer, and potentially beneficial non-pharmacological intervention, particularly suitable for emotional care among institutionalized older adults. Future research is recommended to incorporate objective physiological indicators and long-term follow-up to verify the sustained effects and underlying mechanisms of the intervention. The reduction in PSQI scores was approximately 1 point across the three groups; however, further repeated-measures ANCOVA revealed statistically significant differences among groups. The effect size (Partial η2 = 0.19) indicated a large effect, suggesting that the aromatherapy intervention has meaningful clinical implications for improving sleep quality. These findings support the value of aromatherapy for use in older adult populations.