Dg. Gilbert et al., EFFECTS OF EXAM STRESS ON MOOD, CORTISOL, AND IMMUNE FUNCTIONING - INFLUENCES OF NEUROTICISM AND SMOKER-NON-SMOKER STATUS, Personality and individual differences, 21(2), 1996, pp. 235-246
In a number of studies, neuroticism, depression and stress have been r
eported to be positively correlated with each other, with serum cortis
ol concentration and with smoking. The same factors are inversely rela
ted to measures of immune system functioning. The present study assess
ed in smokers and non-smokers the effects of the presumed stress of fi
nal examinations on moods, cortisol and immune system functioning. Sub
jects were college students selected because they reported Feeling rel
iable high degrees of stress during examinations. Immune system functi
oning (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 a
nd slightly increased symptoms of depression. Further, T lymphocyte pr
oliferation in response to ConA, but not to PHA, was suppressed during
the exam period, while changes in NKCA during exams were associated w
ith an interaction of smoker starts and neuroticism. There was also a
neuroticism by stress interaction for negative mood assessed by the Pr
ofile of Mood States such that those individuals who scored high on me
asures of neuroticism were higher in negative affect at baseline and p
ost-exam periods, bur not during the exam period. Smokers had higher s
erum cortisol concentrations than non-smokers across conditions and sc
ored higher in Beck Depression Inventory-assessed symptoms of depressi
on. Cortisol did not vary as a function of stress and was not correlat
ed with changes in immune functioning, with depression or with negativ
e moods. Serum cortisol and beta-endorphin concentrations were not ass
ociated with immune functioning or habitual nicotine intake (plasma ni
cotine and cotinine concentrations). Among smokers, exam stress did no
t result in elevated plasma nicotine, cotinine or caffeine concentrati
ons. Copyright (C) 1996 Elsevier Science Ltd.