Although early recovery and prevention of depression are important in modern society, antidepressant, that is often the primary pharmacotherapy, produces unwanted adverse effects. We investigated preventive and therapeutic effects, and additionally difference of monotherapy and combined therapy using major traditional medicines, i.e. Kampo (Japanese traditional herbal medicine, saikokaryukotsuboreito) and acupuncture (GV20 and Ex-HN3 as acupoints), which have much less side effects than Western medicine, compared with imipramine measuring immobility time brought by forced swimming (FS) stress. Furthermore, we analyzed its mechanisms according to changes in neurotrophic factors by molecular biology/biochemical method. All the intervention groups in the preventive evaluation and the therapeutic groups in the therapeutic evaluation did not worsen immobility time, and improved prolonged immobility time induced by FS stress respectively. However, there was no significant difference in the time between either the intervention groups or the therapeutic groups. BDNF and NT-3 in acupuncture and combined groups were higher than those in FS group both in the preventive and the therapeutic groups. NGF in the combined group was as same as FS group, and higher than that in acupuncture, Kampo, and imipramine groups in both the preventive and the therapeutic groups. These findings suggest that acupuncture and Kampo improve depression through the regulation of neurotrophic factors, of which mechanism is different from imipramine, and that combined therapy has specific anti-depressive mechanism that does not exert in acupuncture or Kampo alone. We need to utilize more depression rating scales to evaluate the effect of combined therapy more precisely.