Stress, reactivity, and immune function in healthy men.

We examined the effects of acute psychological stress on lymphocyte proliferation and circulating levels of interleukin-1 and -2. Healthy men were exposed to two viewings of a gruesome surgery film and were asked to recall details of the film twice during a 30-min period. These subjects were compared to a nonstress control group. Lymphocyte proliferation to the mitogen concanavalin A (Con A; 5 micrograms/ml) was decreased during and after exposure to the stressor when compared to the control group. This decrease was more pronounced in subjects exhibiting greater blood pressure reactivity while viewing the film than in subjects showing smaller blood pressure responses. None of the other immunological measures was significantly affected by the stressor. Cortisol was not correlated with lymphocyte responsiveness. Possible explanations for these results and implications for further research are discussed.     

The effects of stressor predictability on lymphocyte proliferation in humans

Abstract

To demonstrate the effects of predictable and unpredictable stressors on immune function, 36 male subjects were randomly assigned to complete ten trials of either a predictable or unpredictable cold pressor task or a non-stressful warm pressor control task. The predictable and no-stressor groups were given information about the duration of each pressor trial and a countdown of seconds passed from beginning to end of each trial. The unpredictable stressor group received no information. Self-report, cardiovascular, and biochemical measures were taken throughout the tasks in order to ascertain the effectiveness of the predictability and stressor manipulations. Lymphocyte proliferation to concanavalin A (Con A) and pokeweed mitogen (PWM) were measured before, during and after the tasks. Lymphocyte proliferation to Con A (10/μg/ml) was significantly reduced only in response to the unpredictable stressor suggesting that predictability buffered the effect of the stressor on immune function. Proliferation to PWM followed a similar pattern but was not statistically significant. Blood pressure responses were negatively correlated with proliferation values suggesting that stressor predictability may attenuate stress-associated immune decreases by reducing sympathetic arousal.     

Who benefits from emotional expression? An examination of personality differences among gynaecological cancer patients participating in a randomized controlled emotional disclosure intervention trial

The present study examined the role of neuroticism and extraversion in the effects of written emotional disclosure in patients diagnosed with gynaecological cancer. It was hypothesized that high levels of neuroticism would be associated with an increase in distress after emotional disclosure as mediated by heightened negative affect and avoidance post-disclosure. Conversely, we expected high extraversion to be associated with decreased distress as mediated by heightened positive moods and a decrease in avoidance. Eighty-eight participants were randomly assigned to participate in an expressive writing task versus a control writing task. Distress and avoidance were assessed at baseline and 6 months post-writing. Negative and positive mood were assessed immediately following writing. Multiple regression confirmed that neuroticism but not extraversion moderates the effects of emotional disclosure on distress, however no significant mediating relationships were found.     

The role of objective versus perceived life threat in the psychological adjustment to cancer

Several studies in the oncology literature have used disease stage as a measure of life threat. According to the transactional model of stress (Lazarus and Folkman, ), however, the individual's perception of a threatening situation is more strongly related to distress than the objective event itself. Thus, the present study examined whether cancer patients’ perceived life threat (PLT) is more strongly associated with psychological adjustment than a more objective index of disease prognosis (i.e., cancer stage). In addition, based on cognitive processing theories, this study examined whether intrusive thoughts and avoidance, cognitive characteristics of posttraumatic stress disorder (PTSD), mediate the relationship between PLT and distress. Patients diagnosed with various types of cancer (N = 97) completed questionnaires assessing PLT, cancer-related intrusive thoughts and avoidance, distress, and quality of life. Consistent with theoretical predictions, regression analyses showed that PLT, but not disease stage, was significantly related to psychological distress and quality of life. In addition, intrusive thoughts and avoidance mediated the relationship between PLT and distress. Taken together, these findings suggest that cancer patients’ PLT is more strongly related to distress than is cancer stage and that this association is partly due to cognitive symptoms that are part of PTSD symptomatology. Thus, patients who appraise their illness as life threatening may benefit from cognitive interventions aimed at reducing distress associated with intrusive thoughts.     

Written emotional disclosure buffers the effects of social constraints on distress among cancer patients.

The aims of the present study were to examine whether written emotional disclosure would reduce distress among cancer patients and whether it would buffer the effects of high levels of social constraint (negative social responses to patients' expressions of emotion regarding their cancer) on distress. Cancer patients (N=104) were randomly assigned to write about their emotions regarding their cancer 20 min a day for 3 days or to write about a nonemotional topic. They completed questionnaires at baseline and 6 months postintervention. Results showed that written disclosure buffered the effects of social constraints on stress at the 6-month follow-up and that avoidance partly mediated these effects. The present data reinforce the notion that interventions should be tailored to patients' needs.