This psychobiological study investigates married-coupled group psychotherapy from pre- and postsession serum dopamine dopamine-beta-hydroxylase (DBH) determinations, the Free Association Test (FAT), and a Postsession Questionnaire (PSQ). Experimental manipulations permit controls for the assessment of DBH variations. Group, gender, and individual linear regression analyses are interpreted by a stressor-destrssor typology. DBH levels significantly increase during psychotherapy. Increments are comparable with those from physical work. Most variability in DBH is predicted from a small set of psychological variables. Psychological stressors and destressors show psychobiochemical individuality. Implications of psychological stressors for psychosomatic vulnerability are discussed.