This study aimed to create a better understanding of the neurobiological mechanisms underlying the induction of nocebo hyperalgesia. Nocebo hyperalgesia refers to an increased pain perception...Show moreThis study aimed to create a better understanding of the neurobiological mechanisms underlying the induction of nocebo hyperalgesia. Nocebo hyperalgesia refers to an increased pain perception resulting from negative outcome expectations, a phenomenon that can negatively influence a patient’s clinical outcome. Much concerning the mechanisms underlying the induction of nocebo hyperalgesia is still unknown, although it can be hypothesized that NMDA receptor-dependent learning may play a role. The current study tested this hypothesis by pharmacologically manipulating NMDA receptor- dependent learning in healthy participants, expecting that the pharmacological manipulation would facilitate the induction of nocebo hyperalgesia. Participants (n = 50) received either a placebo or an 80 mg dose of D-cycloserine (DCS), a partial NMDA receptor agonist. Nocebo hyperalgesia was induced in both groups with verbal suggestions and a classical conditioning paradigm consisting of an induction and evocation phase. In the induction phase, high intensity heat-pain stimuli were given during trials where a sham electrical stimulation device was supposedly turned on (nocebo trials), while moderate heat-pain stimuli were given during trials where a sham electrical stimulation device was supposedly turned off (control trials). During the evocation phase, only moderate pain stimuli were given. Nocebo hyperalgesia was indicated when participants rated their pain higher during nocebo trials compared to control trials. A significant paired-samples t-test (t (49) = -8.55, p < .001) suggested that nocebo hyperalgesia was successfully induced in both groups, further confirming that nocebo hyperalgesia can be induced by classical conditioning and verbal suggestions. Nevertheless, the pharmacological manipulation of NMDA receptor-dependent learning with 80 mg DCS did not facilitate the magnitude of the induced nocebo hyperalgesia more than a placebo, as indicated by a one-way ANOVA (F (1, 49) = 0.028, p = 0.867). The usability of DCS in nocebo research was discussed, and further research was recommended. It is important that the current study is replicated, possibly with the use of another glutamatergic agent. The results from future studies could play a significant role in diminishing the impact of nocebo hyperalgesia on clinical practice.Show less
Background: People with type 1 diabetes (T1D) often experience problems with their glucose regulation (glucose variability and glucose control), sleep quality, and cognitive functioning. However,...Show moreBackground: People with type 1 diabetes (T1D) often experience problems with their glucose regulation (glucose variability and glucose control), sleep quality, and cognitive functioning. However, their interrelation has not often been investigated. The aim of this study was to investigate how sleep quality and cognitive functioning are associated with glucose regulation in people with T1D. Method: Continuous glucose monitoring (CGM) data was collected over two weeks, in 18 participants, while each day subjective sleep quality (once in the morning) and cognitive functioning (e.g., ability to concentrate, finding words) (up to five times during the day) was measured using ecological momentary assessments (EMAs). Based on the CGM data, glycemic parameters (glucose variability and glucose control) during the night and day were calculated and a mean value of cognitive functioning per day was composed. Linear mixed model analyses were used to test for 1) whether sleep quality was influenced by glycemic parameters during the night and 2) whether cognitive functioning during the day was influenced by sleep quality and whether cognitive functioning was associated with glycemic parameters during the day. In addition, an interaction effect between sleep quality and glucose variability on cognitive functioning was explored. Lastly, visual plots were used to explore the associations on an individual level. Results: No statistically significant main effects were found for either association. However, an interaction trend (ß = -2.07, p = .070) between sleep quality and glucose variability on cognitive functioning scores was found. For days with normal fluctuations in glucose levels, better sleep quality was associated with better cognitive functioning, whereas for days with high glucose variability, this association could not be found. Regarding the individual plots, both, positive and negative relationships between all mentioned variables were apparent, exemplifying important inter-individual differences. Conclusion: For people with T1D, the relationships between glucose parameters, sleep quality, and cognitive functioning, vary from person to person. This finding advocates for looking at the individual level when implementing possible treatment methods for increasing sleep quality and cognitive functioning. More research in a larger sample is warranted to further examine the inter-individual factors in these associations.Show less
Abstract Yearly, many patients get admitted to the Intensive Care Unit (ICU) worldwide, with even more admissions since the Coronavirus Disease 2019 (COVID-19) pandemic. With the rising survival...Show moreAbstract Yearly, many patients get admitted to the Intensive Care Unit (ICU) worldwide, with even more admissions since the Coronavirus Disease 2019 (COVID-19) pandemic. With the rising survival number, investigating the long-term Health-Related Quality of Life (HRQoL) outcomes, which can be negatively influenced by depressive symptoms, became important. This study investigates whether there is a difference in depressive symptoms between COVID-19 and non-COVID patients that got admitted to the ICU; how depressive symptoms influence the HRQoL, and if there is a difference in HRQoL between COVID-19 patients and non-COVID patients; and if there is a relationship between the self-reported health, happiness, and satisfaction about the ICU stay and depressive symptoms. It was expected that COVID-19 patients would have a higher mean score on depressive symptoms than non-COVID patients, COVID-19 patients with depressive symptoms have lower HRQoL scores than non-COVID patients, and lastly, that there would be a negative relation between the self-reported health, happiness and satisfaction about the ICU stay and depressive symptoms. In this study, 278 patients participated. Approximately one year after ICU discharge, patients filled out a survey. For this study, the Patient Health Questionnaire (PHQ-9), the Euroqol Quality of Life (EQ6D), and general questions about the health, happiness, and satisfaction of the ICU stay were taken into account. An independent t-test demonstrated significant higher mean scores on depressive symptoms in COVID-19 patients than in non-COVID patients (p < .05). Regression analysis showed that depressive symptoms predicted HRQoL (p < .05), but HRQoL was not different between COVID versus non-COVID (p = .225). Regression analysis showed both health and happiness predicted depressive symptoms(p < .05), but not between satisfaction and depressive symptoms (p = .318). The results confirmed our hypothesis that there would be higher mean scores on depressive symptoms in COVID-19 patients than in non-COVID patients. Our findings are clinically relevant and can be used to provide better mental health care after ICU discharge. Follow-up studies should among other things focus on the length of ICU stay, the time during the pandemic that someone got admitted to the ICU, and the depressive symptoms two years after ICU discharge.Show less
Chronic pain occurs in 23% of the Dutch adult population. Psychological factors like expectancies of pain play a big role in pain and methods that can make these expectancies more positive could...Show moreChronic pain occurs in 23% of the Dutch adult population. Psychological factors like expectancies of pain play a big role in pain and methods that can make these expectancies more positive could greatly improve a patient his quality of life. The aim of this study was to examine the relationship between manipulated outcome expectancies and pain. It was hypothesised that a positive outcome expectancy would result in a higher tolerance of pain. 61 healthy students were randomly divided into two groups, where one group received the positive outcome expectancy manipulation and the other group the control manipulation. This was done by presenting information via a computer screen of which the participants believed was about their psychological factors based on a pain test and a questionnaire, but was only based on the group to which the participant was allocated. Pain tolerance was measured using the Cold Pressor Test, where the participant had to hold his/her hand in the water bath for as long as possible and the duration was the measurement for pain tolerance. Both groups showed equal outcome expectancies, p = .193, which means the manipulation was unsuccessful and both groups had the same belief on how well they could tolerate pain. Unsurprisingly, the total amount of time spent in the CPT between the conditions was also the same, p = .988. The research question remains unanswered as the outcome expectancy manipulation was ineffective. A successful manipulation is needed which could be achieved by telling participants face-to-face by a researcher that they are expected to handle pain well, as this might be more convincing and more effective to increase outcome expectancy. Future research could focus on this aspect. This study has gained insight into the possibility that a manipulation via a computer presentation might not be effective enough to induce a positive outcome expectancy.Show less
Nocebo hyperalgesia is the phenomenon in which negative pain expectations lead to augmented pain experiences. Studies have shown that psychosocial factors might influence nocebo hyperalgesia and...Show moreNocebo hyperalgesia is the phenomenon in which negative pain expectations lead to augmented pain experiences. Studies have shown that psychosocial factors might influence nocebo hyperalgesia and facilitate nocebo responses in clinical settings, thus worsening pain. This study aimed to identify whether social stress, fear of pain and pain catastrophizing influence the magnitude of nocebo hyperalgesia. Higher nocebo hyperalgesic responses were anticipated. Additionally, the potential mediating role of subjective stress was explored. Twenty-five healthy male and female participants were recruited and randomly assigned to the experimental (social stress) and control (no-stress) conditions, which underwent the Trier Social Stress Test (TSST) and a friendly version of it (friendly-TSST), correspondingly. Fear of pain and pain catastrophizing were measured with the Fear of Pain Questionnaire-III and the Pain Catastrophizing Scale. Subjective stress was measured on a 0-10 Numeric Rating Scale. A sham electrical stimulation device was applied to induce nocebo along with negative verbal suggestions of pain worsening. Thermal pain stimuli were paired with ON (nocebo trial) and OFF (control trial) visual signs during the acquisition and testing blocks of nocebo conditioning. The first nocebo and control trials of the testing block were compared to estimate the extent of nocebo hyperalgesia. One-way ANOVA, simple linear regression and mediation analysis with the method of bootstrapping were applied (P < 0.05). The one-way ANOVA was non-significant between the social stress and no-stress conditions (P = 0.74). Regression results were non-significant for fear of pain (B = - 0.38, P = 0.11) and pain catastrophizing (B = - 0.30, P = 0.22). Mediation analysis for subjective stress revealed a non significant indirect effect of - 0.009 (95% BCa CI [-1.10, 0.68]). Our study suggests that social stress does not appear to increase the magnitude of nocebo hyperalgesia and that fear of pain and pain catastrophizing might not predict higher nocebo hyperalgesic responses. In addition, subjective stress may not mediate the relationship between social stress and nocebo hyperalgesia. In conclusion, as social stress, fear of pain, pain catastrophizing and subjective stress can co-occur in clinical practices, future research could examine their potential cumulative effect on nocebo hyperalgesia.Show less
Chronic pain is a highly prevalent condition leading to a variety of health problems in the population. t condition and risk factor contributing to a variety of health problems in the population....Show moreChronic pain is a highly prevalent condition leading to a variety of health problems in the population. t condition and risk factor contributing to a variety of health problems in the population. Self-efficacy and optimism are important psychological resilience factors that support individuals’ coping with pain. This study is aiming to investigate if self-efficacy could be manipulated in order to increase and decrease participants’ pain endurance, as well as the role of optimism in the relationship of self-efficacy and pain endurance. Research questions: Would individuals with increased self-efficacy have higher pain endurance? Is the effect of self-efficacy on pain endurance stronger for individuals with higher optimism scores? 36 individuals were recruited for the experiment. Participants were randomly assigned to high and low self-efficacy groups, and their self-efficacy was manipulated accordingly with verbal suggestions. A manipulation check with a self-report VAS scale was introduced to assess the effect of the manipulations. Pain endurance was measured by a cold pressor task (CPT), while optimism was measured by the Lifestyle Orientation Test - Revised (LOT-R) scale. Pain endurance levels of low and high self-efficacy groups were measured via an independent t-test, and the interaction effect of optimism as a moderator between self-efficacy and pain endurance was investigated via a moderation analysis by PROCESS macro in SPSS. The manipulation check showed no significant difference between the scores of the high self-efficacy group and the low self-efficacy group, t(34) = -1.635, p = 1.111. Results showed that there was no significant difference between the pain endurance levels of the low self-efficacy group and the high self-efficacy group, U = 153, p = .77. The moderation analysis showed that while the model was significant, optimism did not have a significant interaction effect (b = -3.42, t(32) = -.62, p = .54). Even though the study is still in progress; the preliminary results are not in line with the related empirical literature. More active involvement of participants in self-efficacy manipulations, a larger sample size, and further investigating the role of optimism is recommended for further assessing the role of self efficacy and optimism in coping with pain.Show less
