Twenty US Navy Underwater Demolition Team (UDT) trainees provided motivational and affect measures, along with simultaneous serum uric acid, cholesterol, and cortisol over 15 blood drawing and questionnaire administrations spanning the first two months of their training. Predominantly positive correlations were seen between the subjects' serum uric acid levels and their estimates of their own motivation. Their serum cholesterol concentrations demonstrated consistently negative correlations with their motivational and pleasant affect scores. Highest correlations were positive ones found between the subjects' serum cholesterol levels and their unpleasant affect scores. Serum cortisol correlations with the three psychological criteria demonstrated wide variability around a zero correlation baseline.
Rahe CRH, Rubin RT, Gunderson EKE. Measures of Subjects' Motivation and Affect Correlated With Their Serum Uric Acid, Cholesterol, and Cortisol. Arch Gen Psychiatry. 1972;26(4):357-359. doi:10.1001/archpsyc.1972.01750220067012