DEPRESSION, PERSONALITY, AND GENDER INFLUENCE EEG, CORTISOL, BETA-ENDORPHIN, HEART-RATE, AND SUBJECTIVE RESPONSES TO SMOKING MULTIPLE CIGARETTES

EEG, hormonal, and subjective effects of smoking multiple cigarettes were assessed in 8 males and 8 females who smoked their own habitual brand of cigarette on one occassion, a nicotine-free control cigarette via a quantified smoke delivery system (QSDS) on another occasion, and standard cigarettes by means of a QSDS on two other occasions. Smoking nicotine-containing cigarettes decreased drowsiness and delta and theta EEG magnitude while it increased serum cortisol. Nicotine enhanced beta2 magnitude significantly more in the right than left hemisphere. Nicotine-induced changes in serum cortisol, drowsiness, and EEG magnitude correlated with each other, such that increases in cortisol correlated with increased arousal. Prior to smoking, nicotine-deprived female nonsmokers, but did not differ in this regard after smoking. Female smokers also reported more trait depression than other participants. Extraversion correlated positively with nicotine-induced decreases in drowsiness, theta, and alpha EEG magnitudes, while neuroticism and depression correlated negatively with these changes. BDI depression score correlated with greater nicotine-free baseline EEG activation of the right than left hemisphere. Nicotine tended to eliminate (normalize) this frontal EEG asymmetry that is characteristic of depressed individuals.