Stressors perceived by the clinical undergraduate medical students towards the end of course

Response or reaction of the mind to the pressure of life is stress. Medical students of Bangladesh are in stress to meet the demands of the curriculum. This study was conducted on the regularly passed final year students of a medical college to find out the nature of stresses perceived by them. The response was collected on a validated structured set of questionnaire, 3 weeks prior to the University level summative examination and 63 students (33 male and 30 female) participated in the study. Stress was expressed in five levels and scored as 0 to 4. Academic related factors were identified as maximum stress provoking (2.5 ± 1.3) than group activity (1.6 ± 1.4), drive (1.4 ± 1.5), teaching-learning (2.3 ± 1.3), personnel (1.8 ± 1.6) or social (1.9 ± 1.5) related factors. Of that group of stress, ‘falling behind reading schedule’ and ‘large amount of content to be learned’ were revealed as heavy stressors. Examination was identified as a severe stressor in 42.4% male, but was marked less (16.7%) in the female. ‘Too much restriction in the campus’ was observed as heavy stressors among the factors other than the academic related stressors. Students may be motivated to develop a coping strategy for academic and teaching-learning related stress.

Prenatal dexamethasone ‘programmes’ hypotension, but stress-induced hypertension in adult offspring

Low birth weight in humans is predictive of hypertension in adult life. Although the mechanisms underlying this link remain unknown, fetal overexposure to glucocorticoids has been implicated. We previously showed that prenatal dexamethasone (DEX) exposure in the rat lowers birth weight and programmes adult hypertension. The current study aimed to further investigate the nature of this hypertension and to elucidate its origins. Unlike previous studies, we assessed offspring blood pressure (BP) with radiotelemetry, which is unaffected by stress artefacts of measurement. We show that prenatal DEX during the last week of pregnancy results in offspring of low birth weight (14% reduction) that have lower basal BP in adulthood (∼4–8 mmHg lower); with the commonly expected hypertensive phenotype only being noted when these offspring are subjected to even mild disturbance or a more severe stressor (up to 30 mmHg higher than controls). Moreover, DEX-treated offspring sustain their stress-induced hypertension for longer. Promotion of systemic catecholamine release (amphetamine) induced a significantly greater rise of BP in the DEX animals (77% increase) over that observed in the vehicle controls. Additionally, we demonstrate that the isolated mesenteric vasculature of DEX-treated offspring display greater sensitivity to noradrenaline and other vasoconstrictors. We therefore conclude that altered sympathetic responses mediate the stress-induced hypertension associated with prenatal DEX programming.

Stress and saltwater-entry behavior of juvenile chinook salmon (Oncorhynchus tshawytscha): conflicts in physiological motivation

Two experiments were conducted to determine the effects of a mild or severe stressor on the saltwater preference of juvenile spring chinook salmon (Oncorhynchus tshawytscha). To observe the response of fish to an overhead threat, we presented stressed fish with an avian predator model in the second experiment. Experiments were conducted in 757-L tanks containing a stable vertical salinity gradient. Only 69% of fish stressed by being chased for 2 min before saltwater introduction (mild stressor) held in salt water, whereas 95% of unchased control fish preferred the saltwater layer. After the more severe handling and confinement stressor, only 20% of fish entered and remained in salt water compared with 100% of unstressed controls. After the presentation of the avian model, stressed fish holding in fresh water moved into the saltwater layer, but this behavioral response was transient. Fish began returning to fresh water within 10 min, and after 1 h, only 26% of stressed fish remained in the saltwater layer. Stress significantly decreases the saltwater preference of chinook salmon that would otherwise select full-strength salt water and may affect behavior in the estuary. Although smoltification primes these fish for seawater residence, stress apparently induced a conflicting physiological motivation.

Defective ACTH response to stress in previously stressed rats: dependence on glucocorticoid status

The effect of previous exposure to stress on the pituitary-adrenal response to a further stress was characterized in rats with different glucocorticoid status: sham-operated rats (Sham), adrenalectomized (ADX) rats, and ADX rats supplemented with a low corticosterone (B) dose in the drinking saline (ADX + B). Previous exposure of Sham rats to 1 h of immobilization (Imo) reduced, 2 h later, the ACTH response to a second severe stressor (Imo) but not to a less severe stressor (tail shock). In ADX rats, previous Imo totally suppressed the ACTH response to Imo or to shock. In ADX + B rats the response to shock was blocked and that to Imo tended to be lower. These changes were not explained by depletion of adenohypophysial ACTH stores. After previous Imo, reduced response to corticotropin-releasing factor was observed in Sham and ADX + B, but not in ADX, rats. Taken together, the present results suggest that the reduced ACTH response of previously stressed rats to a second severe stress is observed in the presence and absence of glucocorticoids, but the main site at which such inhibition occurs might be critically dependent on the glucocorticoid status.

Qualitative and quantitative analyses of a ‘lock and key’ hypothesis of depression

Background. We examine a ‘lock and key’ (‘L–K’) hypothesis to depression which posits that early adverse experiences establish locks that are activated by keys mirroring the earlier adverse experience to induce depression.Methods. Two-hundred and seventy clinically depressed patients were examined with open-ended and pre-coded interview questions to ascertain both early adverse experiences and precipitating life events. Qualitative and quantitative data analyses examined for any associations between developmental ‘locks’ and precipitating ‘keys’.Results. Qualitative assessment suggested ‘L–K’ links in almost one-third of the sample, and examples are provided. While quantitative analyses indicated significant associations between several identical ‘lock’ and ‘key’ constructs, evidence of specificity was rare. When individual ‘locks’ and ‘keys’ were consolidated into three higher-order constructs, variable models were suggested, including a non-specific link, a specific link and absence of any link. ‘L–K’ links appeared more likely in those with ‘non-melancholic’ (versus ‘melancholic’) depression, with the seemingly greater relevance to ‘reactive’ (versus ‘neurotic’) depression in the quantitative analyses inviting speculation that that ‘disorder’ may be more a reaction to a salient rather than a severe stressor.Conclusions. This exploratory study suggests that early adverse experiences may variably establish specific and non-specific patterns of vulnerability to having depression triggered by exposure to salient mirroring life event stressors.