Objective To investigate the clinical features of the first-onset depression in elderly patients by comparing the clinical manifestations and treatment outcomes in the young patients. Methods Sixty elderly patients with first-onset depression who met the CCMD-3 criteria in our department from January to December 2010 were enrolled in the study. Sixty sex and education-level matched young patients with first-onset depression were selected as controlled subjects. A self-made questionnaire was used to analyze the triggers of depression and collect the related data. Selective serotonin reuptake inhabitors (SSRIs) were used to treat depression in both groups for 8 weeks. Hamilton Depression Rating Scale (HAMD) and Hamilton Anxiety Scale (HAMA) were employed to evaluate the depressive and related symptoms in 1, 2, 4, and 8 weeks after the treatment. Results The most common initial symptom was physical complaints in the elderly with first-onset depression. The HAMD total score, anxiety/somatization scores in the elderly were significantly higher than those in younger patients. But the scores of sleep disorders, weight loss and diurnal variation was lower in these elderly than in the control group. HAMA total score and body factors were significantly higher in the elderly patients than the control group. After 8 weeks treatment of SSRIs, the cure rate was 51.7% for the elderly patients, which was significantly lower than that of the control group (91.7%, P＜0.01). Conclusion The most common initial symptoms of the elderly depression are physical complaints. Symptoms such as anxiety, hypochondria, memory loss and physical complaints are more common in the elderly than in the young. But the biological symptoms, such as heavy body weight at morning and light at night are less common in the elderly. The efficacy of SSRIs in the elderly is not as good as for the young depression.