Fear of Dying and Catastrophic Thinking Are Associated with More Severe Post-Traumatic Stress Symptoms Following COVID-19 Infection

Abstract

Numerous investigations have revealed elevated rates of post-traumatic stress symptoms (PTSS) following COVID-19 infection. This study examined the relation between illness-related and psychosocial variables in the severity of PTSS in individuals previously infected with COVID-19. The study sample included 381 individuals who had been infected with COVID-19 within the previous 4 months. Participants completed online measures of infection symptom severity, ongoing COVID-19 symptom burden, fear of dying and catastrophic thinking. Age, infection severity, ongoing COVID-19 symptom burden, and fear of dying and catastrophic thinking were significant correlates of the severity of PTSS. Hierarchical regression analysis revealed that age, gender, ongoing COVID-19 symptom burden, fear of dying and catastrophic thinking each made unique significant contributions to the prediction of the severity of PTSS. The results of the present study suggest that fear of dying and catastrophic thinking about COVID-19 symptoms might contribute to the development of PTSS following COVID-19 infection. Interventions aimed at reducing death fears and modifying negative and alarmist appraisals of COVID-19 symptoms might contribute to more positive recovery outcomes in individuals who are infected with COVID-19. The cross-sectional design of this study precludes statements about causality, and conclusions about temporal relations among variables must await replication in a longitudinal design.

1. Introduction

In March 2020, the World Health Organization (WHO) declared COVID-19 a pandemic [1]. The rapid spread of the virus and the severity of infection led to extreme public health measures in many countries that included the mandatory use of protective equipment, social distancing, isolation, curfews, lockdowns and travel and border restrictions [1]. In severe cases, COVID-19 infection could lead to respiratory failure and death. As of January 2025, there were over 7 million confirmed deaths worldwide due to COVID-19 [2]. Although deaths due to COVID-19 have decreased dramatically over the past two years, researchers have cautioned that future variants of the virus are inevitable, and newer variants may evade the protection of currently available vaccines [3].

Research suggests that the stresses associated with COVID-19 infection might increase the risk of developing post-traumatic stress disorder (PTSD) [4]. The term post-traumatic stress symptoms (PTSS) has been used to refer to the presence of symptoms of PTSD that do not meet all diagnostic criteria for PTSD [5]. Reported prevalence rates of PTSD/PTSS following COVID-19 infection have varied widely [6]. Bradley et al. [7] reported 0% prevalence three months post-infection, regardless of pulmonary function and hospitalization due to COVID-19, while Bo et al. [8] found a strikingly high rate of 96.2% in clinically stable COVID-19 patients assessed prior to their hospital discharge. Nagarajan et al. [6] reported a pooled estimate of 16% prevalence of PTSD across studies of individuals with severe COVID-19 infection. Several studies have investigated factors contributing to PTSD in individuals infected with COVID-19, identifying gender, preexisting mental health conditions, and various psychological factors as key predictors [9,10,11,12].

In other populations, fear of death has been identified as a significant predictor of PTSD [13]. Blanchard et al. [14] examined the relation between fear of dying and the severity of symptoms of PTSD following motor vehicle accidents. Fear of dying predicted the severity of PTSD symptoms even when controlling for injury severity. Simske et al. [15] examined the relation between fear of dying and the severity of PTSD symptoms in patients who were treated in a hospital emergency department following traumatic injury. Their findings revealed that fear of dying emerged as the strongest predictor of the severity of PTSD symptoms even when controlling for injury severity and prior history of mental health problems. Psarros et al. [16] reported that fear of dying was a significant predictor of the development of PTSD in firefighters who were on duty for 10 days during a major wildfire. Malinauskaite et al. [17] reported that fear of dying after an acute coronary event predicted the onset of PTSD. To date, the role of fear of dying as a predictor of the severity of PTSS/PTSD following COVID-19 infection has yet to be examined.

Catastrophic thinking has also been identified as a risk factor for PTSD in a range of populations [18,19,20,21,22]. Cognitive models of PTSD suggest that catastrophic thinking plays a causal role in the development and persistence of PTSD symptoms [23,24]. In a study conducted on soldiers deployed during conflict in the Middle East, Seligman et al. [25] reported that soldiers with high levels of catastrophic thinking were 29% more likely to develop PTSD compared to those with low levels of catastrophic thinking. Pimentel et al. [20] reported that early treatment changes in catastrophizing predicted later changes in PTSD symptom severity in individuals who had experienced traumatic events (i.e., work accidents, victims of crime, exposure to disaster). Pare et al. [26] reported significant bi-directional relations between catastrophic thinking and the severity of PTSS in a sample of individuals receiving treatment for whiplash injury. To date, the role of catastrophic thinking as a predictor of the severity of PTSS/PTSD following COVID-19 infection has yet to be examined.

Fear of death and catastrophic thinking both implicate ‘appraisal processes’ (i.e., evaluative judgments). The role of negative or maladaptive cognitions in the onset and progression of PTSD symptoms has been most explicitly elaborated in Ehlers and Clark’s [27] cognitive model of PTSD. According to this model, negative appraisals of the trauma and/or its sequelae give rise to an ongoing sense of threat and, in turn, contribute to the emergence and persistence of PTSD/PTSS.

The primary aim of the present study was to examine the associations between fear of dying, catastrophic thinking and the severity of PTSS following COVID-19 infection. There are important theoretical and clinical implications to the study of psychosocial predictors of PTSS following COVID-19 infection. From a clinical perspective, fear of dying and catastrophic thinking are appraisals that are potentially modifiable. The identification of modifiable psychosocial risk factors for PTSS following COVID-19 infection might provide the empirical foundation for intervention approaches aimed at preventing or reducing the risk of developing PTSD/PTSS. From a theoretical perspective, the predictive value of conceptual models of PTSS will increase as researchers begin to address more directly how different model-relevant constructs summate or interact to give rise to problematic adaptational outcomes.

2. Materials and Methods

2.1. Participants

The study sample included 381 individuals (105 men; 272 women; 4 other) who had been infected with COVID-19 between 30 and 120 days prior to enrolment. Study advertisements solicited for individuals who had recently been infected with COVID-19. Advertisements were posted on social media platforms (i.e., Facebook, Instagram). Recruitment took place between July 2022 and July 2023.

The 30-day post-infection lower threshold for enrolment was chosen in order to permit examination of the role of ongoing residual COVID-19 symptoms in predicting the severity of PTSS. The 120-day upper threshold was chosen to limit the length of the time over which participants would be asked to recall details of the infection period. Individuals who had a history of mental health problems prior to COVID-19 infection or resided outside of Canada were not considered for participation. Individuals who reported preexisting conditions associated with symptoms that could overlap with COVID-19 infection (e.g., fibromyalgia, chronic fatigue, chronic pain, arthritis, lung or heart disease, and autoimmune disorders) were not considered for participation.

2.2. Measures

Intake Interview. Potential participants were directed to a website that briefly described this study. This study was described as being aimed at examining the physical and psychological consequences of COVID-19 infection. Individuals who were interested in participating were asked to provide contact information and were informed that they would be contacted by someone from our research center. An intake interview was conducted to verify participants’ eligibility for enrolment in this study. Participants provided information about their age, gender, marital status, education, employment, date of infection, post-infection hospitalization, post-infection emergency services, post-infection treatment, and preexisting health and mental health conditions.

Initial Symptom Burden. During the intake interview, participants were asked to respond ‘no’ or ‘yes’ to a list of 15 COVID-19 symptoms that was read to them. Participants were instructed to respond affirmatively to symptoms they had experienced during the first two weeks of infection. The symptom list included the most common symptoms that have been reported following COVID-19 infection: dry cough, fever, shortness of breath, muscle or body aches, headache, nausea/vomiting, fatigue/weakness, loss of smell or taste, problems with memory, attention or concentration, dizziness, hair loss, insomnia, chest pain, weight loss, and hypersomnia. Participants were also asked to report any symptoms they had experienced that were not included on the symptom list. They were informed that the focus was solely on symptoms that developed following COVID-19 infection.

An index of initial symptom burden was computed as a total count of the number of symptoms the participant reported experiencing. The index of initial symptom burden could range from 0 to 16 with higher scores indicating more severe illness.

Ongoing Symptom Burden. During the intake interview, participants were asked to respond ‘yes’ or ‘no’ to a list of 15 COVID-19 symptoms that was read to them. Participants were instructed to respond affirmatively only to symptoms they were currently experiencing. The symptom list was the same as that used to derive the index of initial symptom severity. The index of ongoing COVID-19 symptom burden was computed as the total count of ongoing symptoms reported by participants. The index of ongoing symptom burden could range from 0 to 16 where higher scores reflected greater ongoing symptom burden.

Fear of Dying. During the intake interview, participants were asked to indicate whether they had been afraid they were going to die upon receiving news of their COVID-19 diagnosis: “When you found out that you had COVID-19, were you afraid that you might die from the illness?”. Responses were coded as 0 for “No” and 1 for “Yes”.

Several factors played a role in the choice of a single-item measure of fear of dying. First, of interest was participants’ fear of dying in response to knowing they had contracted COVID-19, as opposed to participants’ enduring or trait-like fear/anxiety about death. Also important was that the measure be consistent with the conceptualization of PTSD as a condition that might develop following exposure to a specific situation or event where individuals thought they might die [28]. Finally, under conditions where an item has a very specific referent and has high face validity, it has been suggested that single-item measures might actually outperform multi-item scales [29].

Catastrophic Thinking. The Symptom Catastrophizing Scale (SCS) was used to assess catastrophic thinking related to the experience of distressing symptoms. Ratings are made on a 3-point frequency scale with the anchors (0) never, (1) sometimes and (2) often. The SCS has been shown to be internally reliable and correlated with measures of symptom severity, post-traumatic stress and disability [20,30,31]. In the present sample, the internal consistency was similar to that reported in the original scale development study, McDonald’s Omega = 0.88 [30].

Post-Traumatic Stress Symptoms. The Post-Traumatic Stress Checklist-5 was used to assess the severity of PTSD symptoms. The PCL-5 is a 20-item self-report measure designed to assess the severity of DSM-5 symptoms of PTSD [32]. Respondents provide a severity rating ranging from 0 to 4 that indicates the degree of distress associated with each symptom from (0) not at all to (4) extremely. Reliability and validity of this measure have been demonstrated in several populations [33,34,35]. A cut-score of 30 on the PCL-5 has been recommended to identify clinically significant PTSS [33].

2.3. Procedure

The Research Ethics Board of McGill University approved the study protocol. Participants provided informed consent to enroll in this study. Following the intake interview, participants were sent a link by e-mail with a request to complete a series of questionnaires online. Questionnaire administration was conducted using REDCap [36]. Participants were compensated USD 50 for completing the intake interview, the SCS and the PCL-5. The study protocol and findings are reported in accordance with the ‘Strengthening the Reporting of Observational studies in Epidemiology’ (STROBE) guidelines for observational studies [37].

2.4. Data Analytic Approach

Data analyses were conducted with SPSS version 29.0. Descriptive statistics were computed on all study variables. t-tests for independent samples were used to analyze gender differences on continuous variables. Chi-square analyses were used to analyze gender differences on categorical variables (i.e., marital status, education, fear of dying). Only 4 individuals identified their gender as ‘other’ and were not included in the gender analyses. Pearson correlations were used to examine inter-relations among dependent variables.

A hierarchical regression analyses was used to assess the relative contributions of symptom-related (e.g., initial symptom burden and ongoing symptom burden) and psychological variables (e.g., fear of dying and catastrophic thinking) to the prediction of PTSS severity. Issues related to temporal order and conceptual primacy were considered in decisions about the order of entry of variables. Age and number of vaccinations were entered first as they would have occurred prior to infection. Infection burden and ongoing symptom burden were entered next as indices of the ‘objective severity’ of the infection. Both variables were computed as a symptom count as opposed to a severity rating to minimize confounding from psychological processes. Initial symptom severity and ongoing symptom burden were entered in separate steps given that the persistence of symptoms is likely to be psychologically experienced as qualitatively different from the experience of the symptoms of acute infection. Fear of dying was entered next as an appraisal that would have been made only after symptoms emerged. Catastrophic thinking was entered last to determine whether an alarmist appraisal of symptom severity contributed to the prediction of PTSS beyond the variables already entered in the analysis.

Direct multiple regressions were used to examine the relative contributions of different COVID-19 symptoms to the prediction of the severity of PTSS. All tolerance coefficients were above 0.45, indicating no problem with multicollinearity.

Power analyses were conducted according to guidelines provided by Fritz and Mackinnon [38]. Assuming medium effect sizes for the relations between symptom severity and PTSS, and the relation between fear of dying, catastrophic thinking and PTSS, in a single-sample model with three covariates (age, gender, education), with N = 381 and alpha set at 0.01, power exceeds 0.80.

3. Results

3.1. Sample Characteristics

The mean age of the sample was 44.1 years (SD = 15.6), and the mean number of days since diagnosis at the time of enrolment in this study was 66 days (SD = 23.8). The majority of participants identified as Caucasian (77%), had completed at least 12 years of schooling (92%), were employed at the time of diagnosis (72%) and had received at least one vaccination (93%). Only a minority of participants required hospitalization (4%).

Means, standard deviations and frequency counts on study variables, stratified by gender, are presented in

Table 1. Sample Characteristics at the Time of Enrolment.

Variable	Men (n = 105)		Women (n = 272)
	n	%	n	%	p
Marital Status					0.11
Single	34	32.4%	107	39.3%
Common law	17	16.2%	59	21.7%
Married	46	43.8%	86	31.6%
Separated/divorced	7	6.7%	12	4.4%
Widow	1	1.5%	8	2.9%
Education					0.01
Less than high school	6	5.7%	2	0.7%
High school	16	15.2%	29	10.7%
Trade school	9	8.6%	19	7.0%
College	24	22.9%	77	28.3%
University	50	47.6%	145	53.3%
Ethic/Racial Background					0.54
Caucasian	77	75.5%	214	79.9%
Black/African	9	8.8%	25	9.3%
Latin/Hispanic	4	3.9%	10	3.7%
Asian	12	11.8%	19	7.1%
	Means	SD	Means	SD
Age (years)	47.1	16.1	44.2	15.4	0.16
Time since diagnosis (days)	61.7	21.0	68.0	24.7	0.02
PCL-5	15.2	14.7	14.8	15.1	0.85
Infection burden	7.6	2.9	7.7	3.3	0.92
Num. vaccinations	1.8	0.9	2.0	1.0	0.27
Ongoing symptom burden	2.2	2.7	2.8	2.8	0.09
Symptom catastrophizing	3.4	3.4	4.0	3.9	0.18
Fear of dying	1.1	0.3	1.2	0.4	0.42

Note. N = 377. SD = standard deviation; PCL-5 = Post-Traumatic Stress Checklist.

. Women and men did not differ significantly with respect to marital status, χ² (4) = 7.5, p = 0.12, Cramer’s V = 0.14, or work status at the time of diagnosis, χ² (1) = 0.99, p = 0.31, Cramer’s V = 0.05. Women were more educated than men, χ² (4) = 11.7, p < 0.01, Cramer’s V = 0.17. Women and men did not differ significantly with respect to age, t (375) = 1.6, p = 0.10, d = 0.19, ethnic background, χ² (4) = 2.1, p = 0.54, Cramer’s V = 0.09, or number of vaccinations, t (375) = 1.1, p = 0.27, d = 0.12. Women reported a greater number of days since diagnosis than men at the time of enrolment, t (375) = 2.2, p < 0.02, d = 0.26.

There were no differences due to gender on measures of initial symptom burden, t (375) = 1.0, p = 0.92, d = 0.07, ongoing symptom burden, t (375) = 1.7, p = 0.09, d = 0.19, fear of dying, χ² (2) = 0.64, p = 0.42, symptom catastrophizing, t (375) = 1.4, p = 0.18, d = 0.15, or PTSS, t (375) = 0.18, p = 0.85, d = 0.02.

3.2. Correlates of PTSS

Pearson correlations among study variables are presented in

Table 2. Zero-order Correlations Among Study Variables.

	1	2	3	4	5	6	7	8
1 PCL-5	-	-	-	-	-
2 Age	−0.21 ***	-	-	-	-
3 Education	0.06	−0.04	-	-	-
4 Days since dx	0.05	−0.10 *	0.02	-	-
5 Num vac.	−0.26 ***	0.34 **	0.20 ***	−0.05	-
6 Inf. burden	0.50 ***	−0.35 **	0.07	0.02	−0.28 ***	-
7 On. burden	0.60 ***	−0.06	−0.06	0.10	−0.25 ***	0.63 ***	-
8 Sym. cat.	0.66 ***	−0.15 **	−0.05	0.09	−0.20 ***	0.49 ***	0.65 ***	-
9 Fear of dying	0.53 ***	−0.14 **	−0.11 *	0.12 **	−0.22 ***	0.38 ***	0.40 ***	0.55 ***

Note. N = 381. PCL-5 = Post-Traumatic Stress Checklist; Days since dx = number of days since diagnosis; Num. vac. = number of vaccinations; Inf. burden = infection burden; On. burden = ongoing symptom burden; Sym. cat. = symptom catastrophizing. The values involving the fear of dying variable are point-biserial correlations. * p < 0.05, ** p < 0.01, *** p < 0.001.

. Significant correlates of the severity of PTSS included age, r = −0.21, p < 0.001, number of vaccinations, r = −0.26, p < 0.001, infection symptom burden, r = 0.50, p < 0.001, ongoing symptom burden, r = 0.60, p < 0.001, fear of dying, r = 0.53, p < 0.001, and symptom catastrophizing, r = 0.66, p < 0.001.

Individuals who had more vaccines were older, r = 0.34, p < 0.001, and more educated, r = 0.20, p < 0.001, and had lower infection burden, r = −0.28, p < 0.001, lower ongoing symptom burden, r = −0.25, p < 0.001, lower fear of dying, r = −0.22, p < 0.001, and lower levels of catastrophizing, r = −0.20, p < 0.001. Individuals with high levels of catastrophizing were younger, r = −0.15, p < 0.01, had higher infection burden, r = 0.49, p < 0.001, higher ongoing symptom burden, r = 0.65, p < 0.001, and higher fear of dying, r = 0.55, p < 0.001.

3.3. Predictors of the Severity of PTSS

A hierarchical regression analysis was used to identify significant predictors of the severity of PTSS. As shown in

Table 3. Hierarchical Regression Predicting Severity of PTSS.

		β	R2change	Fchange (df)	p	sr
Dependent = PCL-5
Step 1			0.04	16.8 (1, 379)	0.001	−0.07 *
	Age	−0.21 ***
Step 2			0.04	15.9 (1, 378)	0.001	−0.03
	Number of vaccinations	−0.21 ***
Step 3			0.15	74.1 (1, 377)	0.001	0.04
	Infection burden	0.42 ***
Step 4
	Ongoing symp. burden	0.52 ***	0.14	103.2 (1, 376)	0.001	0.16 ***
Step 5
	Fear of dying	0.31 ***	0.08	58.7 (1, 375)	0.001	0.16 ***
Step 6
	Symp. catastrophizing	0.35 ***	0.06	45.8 (1, 374)	0.001	0.24 ***

Note. N = 381. β = standardized beta weight at the step at which the variable was entered. sr = semi-partial correlation from the final step of the regression analysis. * p < 0.05, *** p < 0.001.

, in Step 1 of the analysis, age was entered and contributed significantly to the prediction of the severity of PTSS, R²_change = 0.04, p < 0.001. In Step 2 of the analysis, number of vaccinations was entered and contributed significantly to the prediction of the severity of PTSS, R²_change = 0.03, p < 0.001. Infection burden (i.e., number of symptoms during acute infection; Step 3, R²_change = 0.15, p < 0.001) and ongoing symptom burden (i.e., number of COVID-related symptoms participant was still experiencing; Step 4, R²_change = 0.14, p < 0.001) also accounted for significant variance in the severity of PTSS. Fear of dying was entered in Step 5 of the analysis and contributed significant variance to the prediction of PTSS, R²_change = 0.08, p < 0.001. Catastrophic thinking was entered in Step 6 of the analysis, accounting for an additional 6% of the variance in predicting the severity of PTSS, p < 001.

3.4. Subgroup Analyses

The results of the regression analysis suggested that high PTSS might be strongly associated with initial symptom burden and ongoing symptom burden. The relation between symptom burden and PTSS was explored further. For the purpose of these analyses, clinically significant PTSS was defined as a PCL-5 score of 30 or greater. Based on this criterion, 15% of the study sample reported clinically significant PTSS.

Nine (2.4%) participants reported experiencing no symptoms during the acute phase of infection. Twenty-five percent of the study sample reported experiencing 1 to 5 symptoms during acute infection. Seventy-two percent of the study sample reported experiencing 6 or more symptoms during acute infection.

All 15 possible initial symptoms of COVID-19 were entered in a logistic regression with clinically significant PTSS (yes, no) as the dependent variable. The analysis revealed that 3 initial symptoms of COVID-19 made significant unique contributions to the prediction of clinically significant PTSS. These included muscle and body aches (OR = 3.0, 95% CI = 1.2–8.1), shortness of breath (OR = 2.5, 95% CI = 1.1–5.6), and hair loss (OR = 2.5, 95% CI = 1.1–5.5), Nalgelkerke R² = 0.25, χ² = 59.7, p < 0.001.

Approximately one-third (35%) of the study sample reported no ongoing symptoms of COVID-19, another 30% reported between 1 and 3 ongoing symptoms of COVID-19, and 35% reported 4 or more ongoing symptoms of COVID-19. The most prevalent ongoing symptoms of COVID-19 included fatigue (40%), shortness of breath (32%), dry cough (25%), problems with attention and memory (24%) and hypersomnia (22%).

All 15 possible ongoing symptoms of COVID-19 were entered in a logistic regression with clinically significant PTSS (yes, no) as the dependent variable. The results of the analysis revealed that five ongoing symptoms of COVID-19 made significant unique contributions to the prediction of clinically significant PTSS. These included dizziness (OR = 5.0, 95% CI = 2.0–12.0), headache (OR = 4.2, 95% CI = 1.8–9.7), hair loss (OR = 3.3, 95% CI = 1.1–9.9), fatigue (OR = 2.6, 95% CI = 1.1–6.1) and chest pain (OR = 2.5, 95% CI = 1.0–6.9), Nalgelkerke R² = 0.42, χ² = 106.1, p < 0.001.

4. Discussion

The findings of the present study are consistent with previous research showing that trauma severity is a significant determinant of PTSS [14,15]. Across numerous investigations, indices of trauma severity, whether defined in terms of accident severity, intensity of trauma exposure, or illness severity have been found to predict the severity of PTSD/PTSS [39,40]. The findings of the present study extend previous findings by showing that fear of dying and catastrophic thinking accounted for significant unique variance in the severity of PTSS following COVID-19 infection.

4.1. Trauma Severity and PTSS

Prior research has demonstrated that greater trauma severity is associated with higher levels of PTSS [41]. Studies of natural disasters, combat exposure, and sexual abuse have consistently found that individuals who experience more intense or prolonged exposure to trauma exhibit more severe PTSD symptoms [39,40,42]. In the context of illness-related trauma, research has shown that symptom burden and hospitalization are significant predictors of PTSD [43,44]. The present findings align with this body of work, where infection severity and ongoing symptom burden were associated with more severe PTSS.

In other domains of research, the experience of ongoing pain has been discussed as a vulnerability factor for the severity and maintenance of PTSS [45]. For example, significant relations between pain and PTSS has been reported in several groups including individuals with musculoskeletal pain [46], chronic pain [47,48], arthritis [49], fibromyalgia [50], cancer [51], and burns [52]. These findings suggest that prolonged physical symptoms, such as those experienced by individuals with long COVID, might contribute to the maintenance of PTSS.

‘Mutual maintenance’ models have been put forward to explain high rates of co-morbidity of pain and post-traumatic stress symptoms [53,54,55]. It has been suggested that ongoing pain might contribute to the persistence of PTSD symptoms by acting as a “trigger” for memories of the traumatic incident [45]. Clinical and anecdotal evidence supports the view that the symptoms of PTSD can be aggravated by stimuli that resemble aspects of the precipitating traumatic event [56]. Although not explicitly addressed within mutual maintenance models of the persistence of post-traumatic stress symptoms, it is possible that ongoing symptoms of COVID-19 might also act as triggers for traumatic memories of the infection period.

4.2. Fear of Dying as a Predictor of PTSS

Several studies have shown that fear of dying is a significant predictor of the development of PTSS across various trauma-exposed populations, including individuals with life-threatening medical conditions, combat trauma, and near-death experiences [14,17]. In the present study, fear of dying remained a significant predictor of PTSS severity, even when controlling for symptom severity and symptom catastrophizing. The findings suggest that fear of dying might impact on PTSS through pathways that are distinct from the pathways by which symptom severity or the propensity for negative appraisals of one’s symptoms might contribute to PTSS.

During the initial years of the pandemic, death rates associated with COVID-19 infection were quite elevated and widely publicized. The frequent and dramatic reports of the consequences of COVID-19 infection could have led to a mental representation of the ‘diagnosis’ of COVID-19 as a disease that carries a high risk of death [57]. Fear of dying is considered one of the more intense fears that humans experience [58]. It has been suggested that intense fears activate core survival systems in the brain, such as the amygdala and hypothalamic–pituitary–adrenal (HPA) axis, heightening emotional arousal and encoding the experience as traumatic [15]. Perceived proximity to death may be a universal driver of trauma-related distress, regardless of the specific nature of the traumatic event.

4.3. Catastrophic Thinking and PTSS

Catastrophic thinking has been discussed as a key determinant of the development and maintenance of PTSS [27]. Catastrophic thinking has been shown to contribute to the severity of PTSS across various populations [59,60]. Several investigations have shown that treatment-related reductions in catastrophic thinking are associated with decreased severity of PTSS [20,26,61,62]. The present study extends prior work by demonstrating that catastrophic thinking is associated with more severe PTSS following COVID-19 infection, even when controlling for COVID-19 symptom burden and fear of dying.

Gellatly and Beck [24] have proposed that catastrophizing might be a determinant of the onset and maintenance of symptoms of a wide range of health and mental health problems. They propose that catastrophic thinking might be a transdiagnostic maladaptive process, with unique beliefs specific to different psychological conditions. Gellatly and Beck [24] suggest that, although the specific content of catastrophic thinking might vary across different health and mental health conditions, cognitive processes triggered by catastrophic thinking such as interpretive bias, attentional bias, and attentional fixation might act as vulnerability factors common to a wide range of health and mental health conditions.

4.4. Clinical Implications

These findings of the present study invite consideration of treatment approaches that might prevent the development of PTSS in individuals who are infected with COVID-19. The findings suggest that efforts to reduce the perceived mortality threat of COVID-19 infection might prevent the development of post-infection PTSS. Public awareness campaigns, or clinic-based information strategies providing individuals with accurate, evidence-based information about prognosis, recovery trajectories, and the expected duration of post-infection symptoms could help counteract post-infection mortality fears.

Early screening with measures of catastrophic thinking could help identify individuals who are at risk of developing PTSS following COVID-19 infection. Interventions targeting catastrophic thinking and maladaptive fear responses have been shown be effective in reducing PTSS severity [20,21,63,64,65,66]. A disadvantage of many psychological approaches to the treatment of PTSD/PTSS that target catastrophic thinking is that they extend over a period of several months (e.g., 12–16 weeks) thereby impeding their potential adoption as preventive or primary care interventions. However, there have been recent reports of brief one-session interventions for pain catastrophizing that have yielded positive results [67]. Adapting such interventions for individuals recovering from COVID-19 may offer a feasible early intervention strategy for preventing PTSD/PTSS. A meta-analysis of studies examining psychotherapeutic interventions for death anxiety suggests that programs with fewer than 5 sessions yield negligible effects [68]. Higher impact brief interventions targeting fear of dying will need to be developed for the purpose of reducing PTSS following COVID-19 infection.

Several limitations of the present study should be acknowledged. First, while significant correlates of PTSS severity were identified, the cross-sectional nature of this study precludes conclusions about causality. Longitudinal research is needed to determine the temporal relations among infection burden, ongoing symptoms, fear of dying, catastrophic thinking, and PTSS. It is also important to note that the participant sample consisted of Canadians with a high level of education, which may limit the generalizability of the findings to other cultural and socioeconomic contexts. Additionally, it was beyond the scope of the present study to investigate an exhaustive list of variables that might contribute to the severity of PTSS following COVID-19 infection. Psychosocial factors such as coping styles, social support, and preexisting mental health conditions might impact the severity of PTSS as well as on recovery trajectories. Whether the explanatory value of fear of dying and catastrophic thinking is independent of other potential predictors of the severity of post-infection PTSS remains to be clarified by future studies.

5. Conclusions

In spite of these limitations, the present study extends previous research by demonstrating that fear of dying and catastrophic thinking are associated with more severe PTSS in individuals recovering from COVID-19. Research that has been conducted to date indicates that a substantive proportion of individuals who have been infected with COVID-19 will develop clinically significant symptoms of PTSS/PTSD. Although the elevated prevalence and chronicity of PTSD/PTSS following COVID-19 infection are now well established, few studies have isolated specific cognitive–affective risk factors that may underlie these outcomes. By targeting modifiable psychological processes such as fear of dying and catastrophic thinking, early identification and intervention efforts could be strengthened to reduce the risk of long-term functional impairment. Given the known associations between PTSD/PTSS and social withdrawal, family disruption, and prolonged work disability [69,70], efforts to reduce the risk of developing PTSD/PTSS following infection might have important implications not only for patient care but also for mental health policy in the context of pandemic recovery.