In our previous experiments on animals evidence was found that citrus fragrance can restore the stress-induced immunosuppression, suggesting that citrus fragrance may have an effect on restoring the homeostatic balance. Since a dysregulation of the neuroendocrine and immune function is thought to be associated with psychosomatic or psychiatric disorders an attempt was made to restore their mental health by stimulation of one of the sensory systems. Fragrance (citrus was our choice) which comforts through stimulation of the olfactory system was applied to depressive patients. It was given to 12 depressive subjects and the results indicated that the doses of antidepressants necessary for the treatment of depression could be markedly reduced. The treatment with citrus fragrance normalized neuroendocrine hormone levels and immune function and was rather more effective than antidepressants.