This study aimed to identify the factors that influence depression in stressed adults by age. Data were extracted from the 7th Korea National Health and Nutrition Examination Survey, covering 3,333 adults aged 20 to 59 years who were highly aware of stress. Linear regression analysis was performed using the IBM SPSS 25.0 program. The study found that in the case of people in their 20s, education level, health-related quality of life, obesity, weight change, smoking, and subjective body type were significant influencing factors, with an explanatory power of 60.3%. In the case of people in their 30s, gender, household income level, living with spouse, economic activity, health-related quality of life, food intake, obesity, alcohol consumption, smoking, and subjective health were significant influencing factors, with an explanatory power of 30.3%. For people in their 40s, household income level, living with spouse, economic activity, health-related quality of life, smoking, aerobic exercise, and subjective health were significant influencing factors, with an explanatory power of 34.4%. For people in their 50s, gender, education level, income, economic activity, health-related quality of life, protein intake, fat intake, high blood pressure, diabetes, weight control, aerobic exercise, subjective health, and subjective body type were significant influencing factors, with an explanatory power of 42.3%. Therefore, as it was found through this study that the factors affecting depression in stressed adults differ by age, it is necessary to establish an intervention strategy for each age when trying to lower depression in stressed adults.