Mood states in the volunteer blood donor.

Mood changes across time were evaluated as they applied to the process of volunteer blood donation. Measures of mood (from the Mood Adjective Check List) were taken before and at three different intervals after blood donations by 245 college students. Anxiety scores were significantly higher before blood donation, and elation scores showed a significant increase following donation. Veteran donors experienced significantly less discomfort before donation. These findings imply that blood donations can be viewed as an "opponent-affective process," in which initial, mildly aversive feelings lead to positive aftereffects. Current findings suggest that blood donation can be explained, in part, by a self-serving, addictive process.