Physiological measures of skin resistance response, heart rate, respiration rate, and electroencephalogram (EEG) were used in a multiple discriminant analysis to differentiate a group of 10 questionnaire-abnormal Ss from a group of 30 normal Ss. The questionnaire-abnormal Ss were operationally defined as reactively depressed from specified Minnesota Multiphasic Personality Inventory (MMPI) profiles of the 2–4, 2–4–7 code types. The control group was operationally defined by a clinically normal MMPI profile. The method of period analysis was used to electronically transcribe the analog physiological data to digital data for computer manipulation. The depressed group was differentiated from the control group by decreased skin resistance responses, a rapid heart rate, increased respiration rate, and greater activation-complexity of EEG.