Psychoneuroendocrine responses to mental load in an achievement-oriented task

Increased serum cortisol and growth hormone levels in earthquake survivors with PTSD or subclinical PTSD

Alteration of neuroendocrine systems has been demonstrated to be involved in the pathology of posttraumatic stress disorder (PTSD). Three months after an earthquake in Northern China, cortisol, growth hormone (GH) and prolactin (PRL) levels were assessed in 34 earthquake survivors with PTSD (according to DSM-IV criteria), 30 earthquake survivors with subclinical PTSD and 34 normal controls. Only earthquake survivors diagnosed with PTSD had significantly higher serum GH levels. Also, we found that earthquake survivors (either with PTSD or subclinical PTSD) had significantly higher serum cortisol levels. We concluded that PTSD might be associated with an increased level of serum GH and traumatic survivors might be associated with a higher level of serum cortisol.

Acute stressors and cortisol responses: a theoretical integration and synthesis of laboratory research

This meta-analysis reviews 208 laboratory studies of acute psychological stressors and tests a theoretical model delineating conditions capable of eliciting cortisol responses. Psychological stressors increased cortisol levels; however, effects varied widely across tasks. Consistent with the theoretical model, motivated performance tasks elicited cortisol responses if they were uncontrollable or characterized by social-evaluative threat (task performance could be negatively judged by others), when methodological factors and other stressor characteristics were controlled for. Tasks containing both uncontrollable and social-evaluative elements were associated with the largest cortisol and adrenocorticotropin hormone changes and the longest times to recovery. These findings are consistent with the animal literature on the physiological effects of uncontrollable social threat and contradict the belief that cortisol is responsive to all types of stressors.

A case for the usefulness of laboratory social stressors

Although laboratory stress research is a popular and vibrant area of research activity, there is surprisingly little evidence that laboratory stress models are clinically useful (i.e. that they can explain and predict the development of disease). This article summarizes evidence that the usefulness of lab stress research can be improved with the use of social stressors. Two lines of evidence are presented in support of this argument: (a) studies comparing physiological reactivity to different lab stressors with ambulatory activity, and (b) a meta-analysis of investigations of cortisol responses to laboratory stressors. Further issues of importance in understanding social stressors are gender differences and the vulnerability (i.e. weak reliability) of social stressor impact to relatively small changes in the experimental protocol itself.

Initially high plasma prolactin levels are depressed by prolonged psychological stress in males

Plasma levels of prolactin were determined by radioimmunoassay in medical students before and after an academic examination and corresponding control periods. Before the academic examination, both the males' and the females' prolactin values were higher than their control values; they were statistically significant, however, only in the males. After the examination, the prolactin values were lower than the control values in the males, but not in the females. The results partly explain the diverging opinions in the literature regarding the effect of psychological stress on plasma prolactin.

Type A behaviour, borderline hyperventilation and psychological, psychosomatic and neuroendocrine responses to mental task load

Psychological, psychosomatic and neuroendocrine (in blood) responses to mental task load were investigated in relation to Type A behaviour and borderline hyperventilation. For this purpose 32 apparently healthy, male volunteers were classified on the basis of their scores on the Jenkins Activity Survey (JAS) and on a questionnaire assessing hyperventilation related symptoms (HRS). The subjects performed a memory search task in which a monetary bonus could be won or lost. At rest higher HRS scores were related to increased acute psychosomatic symptom scores and higher JAS scores to higher prolactin levels. Task performance caused an increase of state anxiety, acute psychosomatic symptoms, adrenaline and cortisol, whereas prolactin decreased. Higher JAS scores were related to greater cortisol responses and higher HRS scores to smaller adrenaline responses.