Cardiovascular Effects of Grieving

Background

Grief refers to individual's emotional response to real, perceived, and anticipated loss, and is known to induce various psychological symptoms such as depression and anxiety and physical symptoms such as nausea, tension, or fatigue. If a grief reaction is prolonged and left untreated, it could lead to prolonged grief disorder and affect individuals' daily lives. More severe consequences, such as heightened mortality rates, have been observed among bereaved populations, particularly in relation to accidental, violent, and alcohol-related causes, where excess mortality ranges from 50% to 150%. These effects are more pronounced during short durations of bereavement (\<6 months) compared to longer periods and are greater among younger individuals.

Grief is a kind of psychological stress that induces the fight-or-flight response, activating the autonomic nervous system (ANS) and the hypothalamic-pituitary-adrenal (HPA) axis, and in turn, promoting the elevation in the sympathetic nervous system which result in heightened heart rate, blood pressure, blood glucose levels, etc. Specifically, studies have revealed grief's influence on cardiovascular system. Cardiovascular biomarkers affected by short- and long-term bereavement include heightened cortisol levels, dysregulated HPA axis, and more. Many of the effects are long-lasting and highly determined by length of bereavement. For example, a previous study revealed that early bereavement is associated with increased 24-hour heart rate and decreased heart rate variability, and the effect is persistent through 6 months into bereavement. Studies have also shown that immediate grief (grief in response to death of a closed one within 6 months) is correlated with heightened cardiovascular reactivity (CVR) and impaired cardiovascular recovery.

Investigating grief within a laboratory setting presents methodological challenges; however, the Grief Recall (GR) interview offers a standardized approach to eliciting bereavement-related stress. Developed by Dr. Mary-Frances O'Connor at the University of Arizona, GR is an adaptation of the Anger Recall and Separation Recall tasks and utilizes a semi-structured interview to induce grief as the primary stressor. Findings indicate that GR elicits significant increases in systolic blood pressure (SBP) and diastolic blood pressure (DBP) from a resting state, with grief severity predicting the magnitude of SBP elevation. The present study builds upon this work by employing a larger sample size and expanding cardiovascular measurements beyond blood pressure to include heart rate (HR), respiratory sinus arrhythmia (RSA), and cardiac output (CO) and total peripheral resistance (TPR). This approach aims to provide a more comprehensive assessment of cardiovascular responses to grief elicitation within a controlled experimental framework.

Self-affirmation (SA) theory proposes that people are motivated to maintain a positive self-image of being worthy, stable, and capable. The theory also states that when facing threats, people engaging in self-affirmation resist negative consequences by maintaining a self-competent image. Studies have revealed that self-affirmation manipulation targets brain regions responsible for self-processing (medial prefrontal cortex and posterior cingulate cortex), as well as valuation (ventral striatum + ventral medial prefrontal cortex) systems. With increased activity in reward-related brain regions, self-affirmation has been shown in multiple studies to influence stress-related physiological responses in both laboratory and real-life settings. For example, SA significantly reduce cortisol response to laboratory stress tasks, moderated by dispositional self-resources an indicator of hypothalamic-pituitary-adrenal (HPA) axis activity, with effects further influenced by dispositional self-resources. Studies have also been conducted to show a positive buffer effect of SA test on cardiovascular outcomes. For instance, one study revealed that SA tasks attenuate cardiovascular reactivity during negative emotion induction, as evidenced by lower maximum heart rate, higher respiratory sinus arrhythmia (RSA), and overall reduced ratings of negative affect.

Besides blood pressure and heart rate, one key measurement in this experiment is respiratory sinus arrhythmia (RSA). RSA is a form of heart rate variability and is defined as the variation between heart beats coincident with respiration. It is measured by calculating the R-R intervals (time between the R peaks) in the ECG waveform. RSA is controlled by the parasympathetic nervous system and has been shown to be an indicator of stress in laboratory settings. In this study, the investigators propose to measure participants' reactions to grieving stress by RSA. Consider participants' respiration pattern may be affected by sudden mood change during the grief recall task, the study team would also collect impedance cardiography data and use the measurement of respiration rate if needed. Impedance cardiography also provides measures of hemodynamic cardiovascular functioning such as cardiac output and total peripheral resistance.

While SA has been suggested to mitigate grief, its effect on grief has yet to be studied within laboratory settings. Previous studies have argued that "loss of self" is common among divorcing couples, who experience a loss that often involves grieving. Higher ratings of judge-rated loss of self are associated with higher endorsements of complicated grief symptoms among divorced couples. Given the potential for self-affirmation to enhance self-confidence and self-worth, it may also mitigate grief-related stress and physiological stress responses.

Study Protocol

Participants will be recruited from the SONA undergraduate participation pool of University of South Florida. Two RAs will be present during the lab visit. The primary RA is responsible for obtaining consent, guiding the experiment process, and conducting grief-recall interview. The secondary RA is responsible for collecting physiological data by operating the computer in the lab common area. The investigators will add RAs to the protocol through a MOD submitted the IRB.

The informed consent electronic document will be provided to the subjects as they arrive to the lab. After informed consent has been acquired, the subjects will be asked to complete several questionnaires including the Health Questionnaire, the Pre-task Grief Questionnaire, the Beck Depression Inventory (BDI), the Self-Worth Questionnaire (SWQ), the General Anxiety Disorder-7 (GAD-7), the Penn State Worry Questionnaire (PSWQ), the Pittsburgh Sleep Quality Index (PSQI), the Posttraumatic Stress Disorder Checklist (PCL-5), the Perceived Stress Scale (PSS-10), the Inclusion of Others in the Self Scale, the Global Meaning Violation Scale, the Social Relationships Index (SRI) and the Prolonged Grief Disorder (PG-13-Revised) Scale.

Next the participants' heights and weights will be measured, after which cardiovascular measurement equipment will be attached. Then, the participants will sit quietly as they watch an emotionally neutral nature video of Alaska. This rest period will last for 10 minutes, during which ECG impedance cardiography and blood pressure will be measured.

Once resting recordings are obtained, participants will be randomly assigned to the self-affirmation (SA) task or control tasks. The self-affirmation/control task will be administered for10 minutes, during which the study team will collect ECG, impedance cardiography and blood pressure measures. After the task, the subjects will complete self-worth questionnaire (SWQ) before the primary RA enters the room to perform the grief recall (GR) interview. The GR usually will be administered for 10 minutes, during which the study team will collect ECG, impedance cardiography and blood pressure measures.

Once the GR interview is finished, participants will be left alone in the room and instructed to sit quietly for 10 minutes for a recovery period. ECG, impedance cardiography and blood pressure measures will be taken throughout. After recovery, participants will finish the third part of questionnaires, including the third Self-Worth Questionnaire (SWQ), Grief Recall Response Questionnaire, Post-Grief Interview Questionnaire, and the Brief State Rumination Inventory. The research assistant will then conclude the study, thank, and compensate the participant.

Key Methods

Grief Recall: During the Grief Recall interview the PI will conduct a guided interview to promote feelings of grief in bereaved participants. The interview takes roughly ten minutes, during which research assistants ask participants to first recall a situation that happened after they experienced their loss and to wish their lost one was there with them. The grief recall interview has been shown to efficiently promote feelings of grief and elevate blood pressure in laboratory settings. Participants' grief severity was also found to be positively associated with their blood pressure reactivity, highlighting its relevance as a method for assessing cardiovascular outcomes. The GR interview was developed by one of our collaborators, Dr.Mary-Frances O'Connor. Dr. O'Connor has informed us that she has used grief recall in a number of studies with bereaved participants without any adverse events. She will also train the PI and study staff in administering the GR interview. Dr.O'Connor's affiliation to the study will be limited only to train the study PI and the study team. Dr.O'Connor will not be involve in the study procedures or any study activities. The study team do not intend to share identifiable information with Dr.O'Connor or any other collaborators unless permissions are obtained from our respective IRBs.

Self-affirmation intervention: Participants will be randomly assigned to either a self-affirming task or a non-affirming neutral task prior to engaging in grief recall. During the ten-minute self-affirmation task, participants will be asked to rank 11 values they may find important in their lives, and write about their top-ranked feature. This method has been shown to promote participant's self-awareness of their value and self-worth. Participants in no-affirmation control group will be asked to rank their top 12 favorite jellybean flavors and write about the 3rd and 4th favorite flavor for the same duration of time. This control task has also been tested to propose same amount of workload without promoting participants' self-worth.