اثرات استرس امتحان بر روی خلق و خو، کورتیزول، و عملکرد ایمنی بدن: اثرات روان رنجورخویی و وضعیت فرد سیگاری و غیرسیگاری

In a number of studies, neuroticism, depression and stress have been reported to be positively correlated with each other, with serum cortisol concentration and with smoking. The same factors are inversely related to measures of immune system functioning. The present study assessed in smokers and non-smokers the effects of the presumed stress of final examinations on moods, cortisol and immune system functioning. Subjects were college students selected because they reported feeling reliable high degrees of stress during examinations. Immune system functioning (natural killer cell cytotoxic activity [NKCA], and ConA and PHA lymphocyte proliferation), serum cortisol concentration and mood were assessed in 19 smokers and 23 non-smokers. The findings indicate that exam stress was associated with large increases in reported tension and slightly increased symptoms of depression. Further, T lymphocyte proliferation in response to ConA, but not to PHA, was suppressed during the exam period, while changes in NKCA during exams were associated with an interaction of smoker status and neuroticism. There was also a neuroticism by stress interaction for negative mood assessed by the Profile of Mood States such that those individuals who scored high on measures of neuroticism were higher in negative affect at baseline and postexam periods, but not during the exam period. Smokers had higher serum cortisol concentrations than non-smokers across conditions and scored higher in Beck Depression Inventory-assessed symptoms of depression. Cortisol did not vary as a function of stress and was not correlated with changes in immune functioning, with depression or with negative moods. Serum cortisol and beta-endorphin concentrations were not associated with immune functioning or habitual nicotine intake (plasma nicotine and cotinine concentrations). Among smokers, exam stress did not result in elevated plasma nicotine, cotinine or caffeine concentrations.