Correlations between serum cholesterol levels and self-reported intensities of various moods and feelings-namely, motivation, arousal, happiness, depression, anger, fear and lethargy-were investigated in 20 subjects over a 2-month period. Consistent and occasionally significant negative correlations were seen between subjects' serum cholesterol levels and their moods and feelings of motivation, arousal and happiness. Consistent and more frequently significant positive correlations were evidenced between subjects' serum cholesterol concentrations and their moods and feelings of depression, anger, fear and lethargy.