Research Outputs
Peripheral brain-derived neurotrophic factor (BDNF) and salivary cortisol levels in college students with different levels of academic stress. Study protocol
Introduction: Brain-derived neurotrophic factor (BDNF) is essential for brain physiological processes influencing memory and learning. BDNF levels can be affected by many factors, including stress. Stress increase serum and salivary cortisol levels. Academic stress is of the chronic type. BDNF levels can be measure from serum, plasma or platelets, and there is still no standard methodology, which is relevant to ensure reproducibility and comparability between studies. Hypothesis: (i) BDNF concentrations in serum show greater variability than in plasma. (ii) In college students with academic stress, peripheral BDNF decreases and salivary cortisol increases. Peripheral blood and salivary cortisol sampling, measurements 12 mL of peripheral blood (with and without anticoagulant) will be drawn per participant, separated from plasma or serum and cryopreserved at -80ËšC. Additionally, they will be instructed in the collection of 1 mL of saliva samples, which will be centrifuged. Val66Met polymorphism will be performed by allele-specific PCR, while BDNF and salivary cortisol levels will be determined by ELISA. Statistical analysis: (i) descriptive analysis of the variables, through measures of central tendency and dispersion, and the categorical variables through their frequency and percentage. (ii) Then a bivariate analysis will be performed comparing groups using each variable separately. Expected results: We expect to (i) determine the analytical factors that allow a better reproducibility in the measurement of peripheral BDNF, and (ii) the effect of academic stress on BDNF and salivary cortisol levels. General objective: To standardize plasma and serum collection for BDNF levels and to determine whether academic stress affects peripheral BDNF and salivary cortisol levels. Design: Quantitative research, with a non-experimental cross-sectional descriptive design. Participants: Student volunteers. Under convenience sampling, 20 individuals will be included for standardization of plasma and serum collection and between 70 and 80 individuals to determine the effect of academic stress on BDNF and salivary cortisol.
Validity and reliability of SISCO inventory of academic stress among health students in Chile
Objective: To evaluate the factorial structure and internal consistency of SISCO inventory of academic stress in medical students.. Methods: The cross-sectional study was conducted at the School of Medicine, University of Concepcion, Chile, in 2014, and comprised second and third year students.Exploratory factor analysis was carried out to determine the reliability of each of the dimensions of SISCO inventory. Descriptive and correlational analyses were also conducted. Results: Of the 155 students, 121(78.1%)were female. The overall mean age was 20.5+/- 1.55 years (range: 18.9-32.2 years). Of the total, 61(39.4%) students were in the nursing programme, 10(6.5%) in speech therapy, 16(10.3%) in kinesiology, 10(6.5%) in medicine, 20(12.9%) in midwifery and 38(24.4%) in medical technology.For stressor, somatisation and coping dimensions, a factor was identified, with Cronbach's alpha values of 0.76, 0.86 and 0.52, respectively. Correlation could only be established between the first two dimensions. Conclusions: Stressors and somatisation dimensions of the SISCO inventory of academic stress were found to be validity and reliabile.
Inventario SISCO del estrés académico: revisión de sus propiedades psicométricas en estudiantes universitarios
Los estudios superiores representan el punto culminante del estrés académico, proceso multifactorial complejo, con alta carga de trabajo. El inventario SISCO del estrés académico posee buenas propiedades psicométricas para sus subescalas de Estresores, SintomatologÃa y para la puntuación media total, no asà para la subescala de Afrontamiento. El objetivo de este artÃculo es corroborar lo reportado previamente en base a un análisis psicométrico completo. En 1126 estudiantes universitarios, se obtuvieron buenas propiedades psicométricas para las subescalas de Estresores y SintomatologÃa, con un buen ajuste en el análisis factorial confirmatorio, en base a una estructura de cuatro factores. La subescala de SintomatologÃa quedó conformada por las subescalas Reacciones fÃsicas y psicológicas y por Reacciones del comportamiento social. La subescala de Afrontamiento mantiene propiedades psicométricas deficientes. La puntuación para el total de los Ãtems del instrumento muestra buenas propiedades psicométricas (alfa de Cronbach y omega de 0.820 y 0.860, respectivamente). Se corrobora lo reportado previamente, avalándose la necesidad de más estudios, y la modificación del instrumento, en especial la subescala de Afrontamiento.
Academic stress in college students: Descriptive analyses and scoring of the SISCO-II inventory
In a competitive and demanding world, academic stress is of increasing concern to students. This systemic, adaptive, and psychological process is composed of stressful stimuli, imbalance symptoms, and coping strategies. The SISCO-II Academic Stress Inventory (SISCO-II-AS) is a psychometric instrument validated in Chile. It evaluates stressors, symptoms, and coping, both individually and globally. For its practical interpretation, a scale is required. Therefore, this study aims to descriptively analyze the SISCO-II-AS and to obtain its corresponding scales. Employing a non-experimental quantitative approach, we administered the SISCO-II-AS to 1,049 second and third-year students from three Chilean universities, with a disproportionate gender representation of 75.21% female to 24.79% male participants. Through descriptive and bivariate analysis, we established norms based on percentiles. For the complete instrument and its subscales, significant differences by sex were identified, with magnitudes varying from small to moderate. For the full instrument and its subscales, bar scale norms by percentile and sex are presented. Each subscale (stressors, physical and psychological reactions, social behavioural reactions, total reaction, and coping) has score ranges defined for low, medium, and high levels. These ranges vary according to the sex of the respondent, with notable differences in stressors and physical, psychological, and social behavioural reactions. This study stands out for its broad and heterogeneous sample, which enriches the representativeness of the data. It offers a comprehensive view of academic stress in college students, identifying distinctive factors and highlighting the importance of gender-sensitive approaches. Its findings contribute to understanding and guide future interventions. By offering a descriptive analysis of the SISCO-II-AS inventory and establishing bar norms, this research aids health professionals and educators in better assessing and addressing academic stress in the student population.
Increased academic stress is associated with decreased plasma BDNF in Chilean college students
Introduction: Academic stress (AS) is a prevalent challenge faced by university students, potentially affecting molecular indicators such as brain-derived neurotrophic factor (BDNF) and global DNA methylation (G-DNA-M). These indicators could illuminate the physiological ramifications of academic stress. Study Design and Methods: This research followed a quantitative, non-experimental, longitudinal panel design spanning two academic semesters, observing phenomena in their natural context. Students from the Medical Technology program at Universidad de Concepción, Chile were involved, with assessments at the beginning and during heightened academic stress periods. Sample: Of the total participants, 63.0% were females, with an average age of 21.14 years at baseline, and 36.92% were males, averaging 21.36 years. By the study’s conclusion, female participants averaged 21.95 years, and males 22.13 years. Results: Significant differences were observed between initial and final assessments for the SISCO-II Inventory of Academic Stress and Beck Depression Inventory-II, notably in stressor scores, and physical, and psychological reactions. Gender differences emerged in the final physical and psychological reactions. No significant changes were detected between the two assessments in plasma BDNF or G-DNA-M values. A refined predictive model showcased that, on average, there was a 3.56% decrease in females’ plasma BDNF at the final assessment and a 17.14% decrease in males. In the sample, the G-DNA-M percentage at the final assessment increased by 15.06% from the baseline for females and 18.96% for males. Conclusions: The study underscores the physiological impact of academic stress on university students, evidenced by changes in markers like BDNF and G-DNA-M. These findings offer an in-depth understanding of the intricate mechanisms regulating academic stress responses and highlight the need for interventions tailored to mitigate its physiological and psychological effects.
Interaction of Val66Met BDNF and 5-HTTLPR polymorphisms with prevalence of post-earthquake 27-F PTSD in Chilean population
Post-traumatic stress (PTSD) disorder is a mental health condition that can occur after experiencing or witnessing a traumatic event. The 27-F earthquake that struck Chile in 2010 was one such event that had a significant impact on the mental health of the population. A study was conducted to investigate the prevalence of PTSD and its associated factors among survivors of this earthquake. The study was a longitudinal design, involving a sample of 913 patients aged 18 to 75 years who attended 10 Primary Care Centers in Concepción, Chile. The Composite International Diagnostic Interview (CIDI) was used to assess both depressive episodes (DE) and PTSD before and after the earthquake. The study also involved genotyping studies using saliva samples from the participants, specifically focusing on the Val66Met and 5-HTTLPR polymorphisms. Statistical analysis was performed to examine the association between different variables and the presence of PTSD. These variables included demographic factors, family history of psychiatric disorders, DE, childhood maltreatment experiences, and critical traumatic events related to the earthquake. The results showed that the incidence of post-earthquake PTSD was 11.06%. No significant differences were found between the groups of participants who developed post-earthquake PTSD regarding the Val66Met or 5-HTTLPR polymorphisms. However, a significant association was found between the concomitant diagnosis of DE and the development of post-earthquake PTSD. The presence of DE doubled the risk of developing post-earthquake PTSD. The number of traumatic events experienced also had a statistically significant association with an increased risk of developing post-earthquake PTSD. The study’s limitations include the potential interference of different DE subtypes, the complexity of quantifying the degree of earthquake exposure experienced by each individual, and events entailing social disruption, such as looting, that can profoundly influence distress. In conclusion, the study found that PTSD following the 27-F earthquake in Chile was associated with a concomitant diagnosis of DE and the number of traumatic events experienced. The study did not find a significant association between PTSD and the Val66Met or 5-HTTLPR polymorphisms. The researchers recommend that mental health professionals should prioritize the detection and treatment of concomitant depressive episodes and exposure to critical traumatic events in survivors of disasters. They also suggest that further research is needed to better understand the relationship between genetic factors and post-disaster PTSD.
Propiedades psicométricas del Inventario SISCO-II de estrés académico
Estrés académico, proceso multifactorial complejo que alcanza sus grados más elevados a nivel universitario y que para realizar intervenciones efectivas, necesita de instrumentos válidos y fiables para medirlo. El objetivo de este trabajo fue evaluar las propiedades psicométricas de una versión adaptada del inventario SISCO del estrés académico, denominada SISCO-II, destinada a medir estrés académico en estudiantes universitarios. Se aplicó el instrumento a 1.126 estudiantes universitarios de tres universidades chilenas. El análisis factorial confirmatorio mostró buen ajuste a la estructura propuesta de cuatro factores (Estresores, Reacciones fÃsicas y psicológicas, Reacciones del comportamiento social y Afrontamiento). La medida de estrés académico queda constituida por estresores, reacción total (Reacciones fÃsicas, psicológicas y del comportamiento social) y estrategias de afrontamiento. Los resultados avalan la utilidad de SISCO-II para uso diagnóstico y evaluación de intervenciones, siendo una escala válida y confiable.