A glycolipid having GalNAc alpha1-3GalNAc in the terminal increases a behavior climbing in a depression model, mouse forced swimming. Antidepressants, which sometimes induce hypomanic state in patients, increase the glycolipid and an anti-manic substance lithium decreases the glycolipid in mice. We detected the humoral GalNAc alpha1-3GalNAc-lipid reactivity of humans in different affective states. Although the reactivity was also showed in serums of the depression patients and the volunteers without affective disorders, the reactivity was remarkably increased in serums of hypomania patients. These strongly suggest that the humoral glycolipid increased the activities of the hypomania patients, but did not relate to the decrease of the activities in the depression patients.