The concept of stress

[The sovereignty of the visible: how traumatic memory becomes traumatic stress]

Since the release of the third version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III), biological psychiatry has been systematically applying its classification reasoning to social phenomena of many natures. From this perspective, the discourse of trauma gained relevance and events of devastating magnitude began to receive neurobehavioral interpretations until finally being recognized less for their cultural and subjective effects than for the physiological changes they cause. By a narrative review, this study aims to analyze the transition of traumatic rationality from the 19th century, when trauma was associated with the cognitive concept of memory, to the 20th century, when this phenomenon was finally attached to neuroscientific research on stress. The plurality of conceptual models and deterministic paradigms can contribute to the fact that trauma research produces multifactorial coping protocols more appropriate to the human experience of post-traumatic suffering.

Psychosocial stress and cancer risk: a narrative review

BACKGROUND

It is unclear which psychological factors (stressors, emotional correlates, and psychophysiological markers) induce cancer risk. This currently limits the potential for prevention strategies.

PURPOSE

The aim of this review is to bring forth evidence of stress as a determinant of cancer risk from a public health perspective, written for a broad public of practitioners and scientists.

METHODS

Based on a semisystematic literature search, the impact of different aspects/types of stress and the potential physiological and behavioral pathways are summarized, while highlighting further research, public health and clinical implications.

RESULTS

Between 2007 and 2020, 65 case-control or cohort studies have been identified. Apart from overall cancer ( N = 24), 12 cancer types have been associated with psychological stress with most for breast ( N = 21), colorectal ( N = 11) and lung/prostate/pancreas cancer ( N = 8 each). Although the evidence regarding the mechanisms is still scarce, cancer development in relation to stress might be due to interacting and combined effects of different stress(or) types, but such interaction has not really been tested yet. The path from stress towards cancer incidence consists of a biological pathway with endocrinology and immunology as well as stress-induced behavioral pathways, including smoking, alcoholism, sleep disruption, an unhealthy diet, and low physical activity together with the related phenomenon of obesity.

CONCLUSION

Not only the stress but also the stress-induced lifestyle should be targeted for cancer prevention and treatment. Future research should include a more diverse spectrum of cancer types (not only hormonal related like breast cancer) and of stress measures while also considering behavioral covariates.

The impact of oxytocin on thiol/disulphide and malonyldialdehyde/glutathione homeostasis in stressed rats

We aimed to investigate the impact of oxytocin on serum thiol/disulphide and malonylyldialdehyde (MDA)/glutathione balance under acute stress (AS) and chronic stress (CS) exposure in rats. Animals were allocated into control (C), AS and CS groups, then the groups subdivided as intranasal oxytocin or saline applied groups, randomly. Animals in the AS or CS groups were exposed to combined cold-immobilisation stress. Salivary corticosterone levels and elevated plus maze (EPM) scores were used to assess stress response. MDA, glutathione, thiol-disulphide levels were measured in the serum samples. Oxytocin treatment attenuated stress response regardless of the stress duration verified by lower corticosterone level and favorable profile in EPM parameters measured. Furthermore, oxytocin modulated oxidant profile suggesting lowered oxidant stress with decreased serum MDA/glutathione and disulfide/native thiol ratios. Oxytocin improves the response of organism to stress via both its anxiolytic and antioxidant effects. That's why it can be considered as a protective measure to employ methods to increase endogenous oxytocin and/or to apply exogenous oxytocin to prevent stress-induced increase in oxidant stress, which plays a pivotal role in the pathogenesis of various stress-related diseases.

The Changes in 1H-MRS Metabolites in Cuprizone-Induced Model of Multiple Sclerosis: Effects of Prior Psychological Stress

Stress is considered as an important risk factor in the progression and the onset of many disorders such as multiple sclerosis. However, metabolite changes as a result of demyelination under the detrimental effects of stress are not well understood. Thus, 36 female Wistar rats (i.e., groups (1) no-cuprizone (Cont), (2) no-stress + cuprizone-treated (Cup), (3) physical stress + cuprizone-treated (P-Cup), (4) psychological stress + cuprizone-treated (Psy-Cup), (5) physical stress + no-cuprizone-treated (P), (6) psychological stress + no-cuprizone-treated (Psy)) were used in this study. Following induction of repetitive stress, cuprizone treatment was carried out for 6 weeks to instigate demyelination in all groups except the control animal. Relative metabolite concentrations of the brain were investigated by single-voxel proton magnetic resonance spectroscopy (reporting N-acetyl-aspartate (NAA), glycerophosphocholine with phosphocholine (tCho) relative to total creatine (tCr)). According to ¹H-MRS, rats in the Cup group indicated a reduction in NAA/ tCr (p < 0.001) as well as tCho/ tCr (p < 0.05) compared with that in the Cont group. In contrast, in both stress + cuprizone-treated groups, NAA/tCr and tCho/tCr ratios remarkably increased versus the Cup group (p < 0.001) and the Cont group (p < 0.001 for the Psy-Cup group and p < 0.05 for the P-Cup group). Both P and Psy groups revealed normal metabolite concentrations similar to the Cont group 6 weeks post stress. Seemingly, in the case of cuprizone alone, decreased level of metabolites is mainly relevant to neuronal cell impairments. Meanwhile, as a result of oxidative stress enhancement due to stress exposure, oligodendrocyte becomes the main victim indicating the increased level of metabolite ratios.

Psychological stress effects on myelin degradation in the cuprizone-induced model of demyelination

Multiple sclerosis (MS) is known as the most common demyelinating disease worldwide in which previous studies have shown that stress is a risk factor for the disease's onset and progression. Nevertheless, further studies are needed to investigate the consequences of stress in MS pathology. In this study, after 5 days of exposure to psychological and physical stress as a repetitive distress modality, rats were treated with cuprizone. The demyelination degree was compared in animal groups using Luxol fast blue staining, immunohistochemical staining for myelin basic protein and transmission electron microscopy. Outcomes revealed that animals exposed to stress prior to cuprizone ingestion, elicit more intense demyelination. Continuous psychological distress has more severe effects on myelin sheath destruction in the preclinical stage.

Acute Stress Decreases but Chronic Stress Increases Myocardial Sensitivity to Ischemic Injury in Rodents

Cardiovascular disease (CVD) is the largest cause of mortality worldwide, and stress is a significant contributor to the development of CVD. The relationship between acute and chronic stress and CVD is well evidenced. Acute stress can lead to arrhythmias and ischemic injury. However, recent evidence in rodent models suggests that acute stress can decrease sensitivity to myocardial ischemia-reperfusion injury (IRI). Conversely, chronic stress is arrhythmogenic and increases sensitivity to myocardial IRI. Few studies have examined the impact of validated animal models of stress-related psychological disorders on the ischemic heart. This review examines the work that has been completed using rat models to study the effects of stress on myocardial sensitivity to ischemic injury. Utilization of animal models of stress-related psychological disorders is critical in the prevention and treatment of cardiovascular disorders in patients experiencing stress-related psychiatric conditions.

Life events and chronic physical conditions among left-behind farmers in rural China a cross-sectional study

BACKGROUND

This study investigates the relationships between life events and chronic physical conditions among left behind farmers, a newly emerged weak group in vast rural China.

METHODS

The study collected information about life events, chronic physical conditions, blood pressure and fasting blood glucose from 4681 famers living in 18 randomly selected villages (Lu'an, Anhui, China) from early November 2013 to the end of December 2013. It compared the risk and odds ratios (RRs/ORs) among different subgroups divided according two life event indices derived by adding up un-weighted-ratings and weighted-ratings based on multivariate logistic regression coefficients respectively.

RESULTS

A total of 4040 (86.3 % eligible) farmers completed the survey. RRs between farmers with lower than the first 1/15-percentile of life event index and with higher life event index scores ranged 1.43-5.79 for chronic gastritis and 0.42-9.07 for prostatitis, 1.01-4.97 for cervicitis/vaginitis, 1.45-3.28 for cardio-cerebrovascular diseases, 1.12-1.58 for hypertension, 1.00-1.66 for diabetes, 1.07-3.35 for pre-diabetes and 5.00-55.00 for "other chronic physical conditions".

CONCLUSIONS

Life events were independently linked with most of the chronic physical conditions in a dose-effectiveness way. RRs between subgroups divided by given percentile cutoff points of life event index compiled using logistic regression models turned out to be substantially higher than that between subgroups divided by same cutoff points of life event index produced via summing up the un-weighted Likert ratings of all the events studied.

Influence of stressors on breast cancer incidence in the Women's Health Initiative

OBJECTIVE

To examine associations among life events stress, social support, and breast cancer incidence in a cohort of postmenopausal women. DESIGN AND MAIN OUTCOME MEASURE: Women's Health Initiative observational study participants, breast cancer free at entry, who provided assessment of stressful life events, social support, and breast cancer risk factors, were prospectively followed for breast cancer incidence (n = 84,334).

RESULTS

During an average of 7.6 years of follow-up, 2,481 invasive breast cancers were diagnosed. In age-adjusted proportional hazards models, 1 stressful life event was associated with increased risk, but risk decreased with each additional stressful life event. After adjustment for confounders the decreasing risk was not significant. Stressful life events and social support appeared to interact in relation to breast cancer risk such that women who had greater number of stressful life events and low social support had a decreased risk of breast cancer.

CONCLUSIONS

This study found no independent association between stressful life events and breast cancer risk. The results are compatible with a more complex model of psychosocial factors interacting in relation to breast cancer risk.

The Type A/B behaviour pattern in samples of urban and rural men

The present study assessed the prevalence of the Type A behaviour pattern in a rural and an urban sample of men in Norway. The study was carried through on data collected for other purposes, reported earlier in 1998 and 1999, to evaluate whether there were differences in Type A behaviour pattern between the two environmental settings. The Type A behaviour pattern was assessed in both studies using the Jenkins Activity Survey. Analysis of the data on the Global Type A scale indicated that, on average, participants in both environments reported as Type Bs as opposed to Type As. However, the distribution of scores on the subscales of the Jenkins Activity Survey showed that mean scores on the Type A behaviour attributes were higher in the urban sample than those in the rural sample. The results concerning the expression of the Global Type A from these samples supported expectations about differences in challenges of a competitive environment such as an urban setting, expressed in the literature.

Epidemiological evidence for a relationship between life events, coping style, and personality factors in the development of breast cancer

OBJECTIVE

Review empirical evidence for a relationship between psychosocial factors and breast cancer development.

METHODS

Standardised quality assessment criteria were utilised to assess the evidence of psychosocial predictors of breast cancer development in the following domains: (a) stressful life events, (b) coping style, (c) social support, and (d) emotional and personality factors.

RESULTS

Few well-designed studies report any association between life events and breast cancer, the exception being two small studies using the Life Events and Difficulties Schedule (LEDS) reporting an association between severely threatening events and breast cancer risk. Seven studies show anger repression or alexithymia are predictors, the strongest evidence suggesting younger women are at increased risk. There is no evidence that social support, chronic anxiety, or depression affects breast cancer development. With the exception of rationality/anti-emotionality, personality factors do not predict breast cancer risk.

CONCLUSION

The evidence for a relationship between psychosocial factors and breast cancer is weak. The strongest predictors are emotional repression and severe life events. Future research would benefit from theoretical grounding and greater methodological rigour. Recommendations are given.

Psychological distress and psychiatric morbidity in women prisoners

The population of a women's prison (n = 92) was screened for psychological distress and psychiatric morbidity with the 12-item General Health Questionnaire, the Hamilton Depression Rating Scale, a Recent Stressful Life Events questionnaire and the Structured Clinical Interview for DSM-III-R. High levels of symptoms of psychological distress were recorded. Distress was correlated with recent stressful life events and was more severe in women awaiting trial. Fifty-three per cent of the prisoners were diagnosed as current cases of a psychiatric disorder and the most frequent diagnoses were adjustment disorder with depressed mood and personality disorders. Lifetime prevalence of psychoactive substance use disorders was 54 per cent. Aboriginal women were over-represented in this prison population. A follow-up survey after 4 months showed no fall in the prevalence of psychological distress and psychiatric morbidity.

Traumatic stress disorder: diagnostic and clinical issues in former prisoners of war

Examined are a variety of clinical issues in the diagnosis and treatment of Posttraumatic Stress Disorder (PTSD) of former prisoners of war (POWs). Difficulties and complexities in understanding and diagnosing PTSD in former POWs presenting symptomatic complaints associated with this disorder are explored. Data collected on former POWs complaining of PTSD and diagnosed by DSM-III-R criteria revealed Minnesota Multiphasic Personality Inventory (MMPI) and Millon Clinical Multiaxial Inventory (MCMI) clinical profiles appropriate for clinical application. Comparative data between German-held and Japanese-held POWs experiencing PTSD and adjustment-related stressors are discussed. Import on clinical strategies with diagnosed patients suggests both behavioral approaches to treatment and future directions in research.