Terror catastrophizing: association with anxiety, depression, and transgenerational effects

ABSTRACT

Background & Objectives: Terror catastrophizing, defined as an ongoing fear of future terrorist attacks, is associated with a higher incidence of anxiety disorders, among other psychological impacts. However, previous studies examining terror catastrophizing’s relationship to other mental health disorders are limited. The current study sought to determine if patients diagnosed with anxiety and depression would experience increased terror catastrophizing. Additionally, this study aimed to investigate whether parental terror catastrophizing increases children’s internalizing symptoms.

Design & Methods: Individuals were randomly drawn from the Danish Civil Registration System and invited to complete a series of questionnaires to measure terror catastrophizing tendency, lifetime parental trauma, and children’s internalizing symptoms. In total, n = 4,175 invitees completed the survey of which 933 reported on a child between 6 and 18 years. Responses were analyzed using a generalized linear regression model.

Results: Participants diagnosed with anxiety alone or comorbid with depression were more likely to experience symptoms of terror catastrophizing than undiagnosed participants (β = 0.10, p < .001; β = 0.07, p = .012). Furthermore, the parental tendency to catastrophize terror was associated with higher internalizing symptoms in children (β = 0.09, p = .006), even after taking parental diagnoses, as well as lifetime and childhood trauma into account.

Conclusion: The results can inform clinical practices to account for a patient’s potential to exhibit increased terror catastrophizing tendencies or be more affected by traumatic events. Additionally, they can offer insights for designing novel preventative interventions for the whole family, due to the relation between parental tendencies for terror catastrophizing and the internalizing symptoms observed in children.

HIGHLIGHTS

• Diagnoses of comorbid anxiety and depression tend to have increased terror catastrophizing (TC); however, a sole anxiety diagnosis is associated with more TC, while sole depression is not.

• Informative for clinical practice to understand how patients with TC tendencies are more likely to be impacted by traumatic events.

• Parental TC symptoms are linked to internalizing symptoms in children; thus, this could inform the design of novel preventative interventions.

Antecedentes y Objetivos: El terror catastrófico, definido como el miedo permanente a futuros ataques terroristas, está asociado con una incidencia mayor de trastornos ansiosos, entre otros efectos psicológicos. Sin embargo, estudios previos que exploraban la relación del terror catastrófico con otros desordenes de salud son limitados. El presente estudio busca determinar si los pacientes diagnosticados con ansiedad y depresión experimentan mayor terror catastrófico. Adicionalmente, este estudio apunta a investigar si el terror catastrófico de los padres incrementa la posibilidad de que los hijos internalicen los síntomas.

Diseño y métodos: Los individuos fueron elegidos al azar desde el Sistema civil de registro danés, y fueron invitados a completar una serie de cuestionarios para medir la tendencia al terror catastrófico, trauma parental durante su vida, y síntomas internalizantes de los hijos. En total, n = 4.175 invitados completaron la encuesta de los cuales 933 reportaron tener un niño entre 6 y 18 años. Las respuestas fueron analizadas usando un modelo de regresión lineal generalizada.

Resultados: Los participantes diagnosticados solo con ansiedad o en comorbilidad con depresión fueron más propensos a experimentar síntomas de terror catastrófico que los participantes sin diagnostico (β = 0.10, p < .001; β = 0.07, p = .012). Además, la tendencia parental al terror catastrófico estaba asociada con mayores síntomas internalizantes en los hijos (β = 0.09, p = .006), incluso luego de considerar diagnósticos de los padres, trauma en la niñez o a lo largo de la vida.

Conclusión: Los resultados pueden informar prácticas clínicas para tener en cuenta de que un paciente presente una mayor tendencia al terror catastrófico o se vea más afectado por los eventos traumáticos. Adicionalmente, puede ofrecer conocimiento para diseñar nuevas intervenciones preventivas para toda la familia, debido a la relación entre las tendencias de terror catastrófico de los padres y los síntomas internalizantes observada en los hijos.

KEYWORDS:

• Terrorism
• online surveys
• internalizing symptoms
• lifetime trauma
• childhood trauma

PALABRAS CLAVE:

• Terrorismo
• encuesta en línea
• síntomas internalizantes
• trauma durante la vida
• trauma en la infancia

1. Introduction

Terror catastrophizing (TC) is defined as an ongoing fear of future terrorist attacks and its unpredictable consequences. It is associated with a higher incidence of anxiety disorders, among other psychological impacts (Abiola et al., 2018; Rigutto et al., 2021), and it is characterized by rumination, magnification, and helplessness (Shechory-Bitton & Cohen-Louck, 2020; Sinclair & LoCicero, 2007). A tendency for TC was most prominently observed in Western countries after the 9/11 attacks on New York City’s World Trade Center, which sparked the fear of additional attacks worldwide due to the high number of casualties, the severity of the attack, and threats of further attacks (Gökyar & Erdur-Baker, 2021). Following these attacks, people who were not affected also experienced post-traumatic stress disorder (PTSD) symptoms, showing that TC can broadly affect people, from those who personally experience it to those who only hear about such events from the media (Galea et al., 2003; Gökyar & Erdur-Baker, 2021). Interestingly, certain populations seem to be more prone to develop a tendency for TC. Although both men and women exhibit TC, women and the elderly are often more distressed by death and terrorism (Nayab & Kamal, 2010; Shechory-Bitton & Cohen-Louck, 2020); thus, it is crucial to consider participants’ age and gender to improve our understanding of the tendency for TC in different groups. Feelings of distress are further amplified in parents, who feel responsible for protecting their offspring (Gökyar & Erdur-Baker, 2021). Due to the significant relationship between adverse family contexts and the incidence of psychological disorders in youths, socioeconomic status (SES) must be considered as a contextual factor in the psychological impact of TC within families. This is crucial since low income and economic stress are predictors of anxiety and mood disorders (Roberts et al., 2009). Fear, stemming from TC, can cause psychological impacts including shock, anxiety, and feelings of helplessness, which can lead to serious mental health challenges like PTSD and depression (Gökyar & Erdur-Baker, 2021). However, previous research has shown that TC elicits specific physiological responses to adapt to stress (Shenhar-Tsarfaty et al., 2015), differentiating it from disorders like PTSD and generalized anxiety disorder (GAD).

Present investigations into the co-occurrence of a tendency for TC across various mental health disorders are limited; most studies conducted so far have been primarily concentrated on patients with PTSD, depression, and anxiety disorders (Rigutto et al., 2021). For example, Abiola et al. (2018) examined the psychological burden of TC. They found it to be moderately correlated with higher incidence rates of GAD and depression in general. Previous studies have also examined the mediating role of perceived stress, how an individual feels about their stress, and death anxiety, a fear of death or dying, on TC, but they do not account for mental health diagnoses (Doak & Katsikitis, 2017; Nayab & Kamal, 2010).

While more recent studies have found an association between terrorism and negative mental health effects in the long term, they did not examine the tendency for TC specifically (Gökyar & Erdur-Baker, 2021). In addition, multiple studies have reported a relationship between exposure to terrorism and PTSD, as well as anxiety and mood disorders (Hansen et al., 2016; Jordan et al., 2019). However, it remains unclear whether patients with depression and anxiety disorders are more likely to have a tendency for TC per se or whether this could be explained by the higher traumatization rates commonly observed among these patients (Xie et al., 2018).

Similarly, it is unclear how childhood trauma experiences relate to the tendency for TC. Childhood trauma is a known risk factor for serious and long-lasting impact with wide-ranging psychological and physical consequences (Xie et al., 2018). A systematic review has shown that any type of childhood trauma will result in higher anxiety, depression, or their comorbid presentation – linearly increasing with the severity of childhood trauma an individual experienced (Kuzminskaite et al., 2021). Childhood and lifetime sexual abuse, in particular, is associated with increased anxiety and depression in addition to other mental disorders (Chen et al., 2010). Moreover, Kuzminskaite et al. (2021) found that childhood trauma is positively correlated with higher levels of rumination and helplessness, which are important contributing factors to the tendency for TC and poorer mental health outcomes (Sinclair & LoCicero, 2007). Accordingly, experiencing childhood trauma could render an individual more vulnerable to develop a tendency for TC. However, no research has been conducted so far examining the relationship between childhood trauma and TC.

Finally, it remains an important question how childhood trauma relates to TC and poorer mental health, not only within an individual but also across generations. Transgenerational effects have been documented for parental trauma experiences with parental trauma exposure resulting in the poor mental health of the children, independent of the children’s own trauma exposure (Snyder et al., 2016; Stenz et al., 2018). This is most clearly observed in Holocaust survivors; significantly higher rates of mental health disorders were found among offspring of Holocaust survivors compared to offspring of parents without such a traumatic experience (Dashorst et al., 2019). Parental lifetime trauma exposure has also been shown to increase the children’s likelihood of developing internalizing symptoms such as separation anxiety and harm avoidance (Cho et al., 2021). Similarly, research has shown that parental PTSD, depression, and anxiety diagnoses are linked to children’s higher internalizing symptoms (Glaus et al., 2021; Snyder et al., 2016). Children's internalizing symptoms are hypothesized to be partially the result of a child’s familial and societal interactions (Kidd et al., 2022). Along these lines, children who interacted with mothers who experienced depression were found to be much more likely to develop internalizing symptoms themselves (Vreeland et al., 2019). However, the transgenerational impact of TC has not been studied so far, although parental tendencies for TC are likely to display a strong negative association with children's mental health.

The current study aims to close these gaps in the literature by addressing the following key questions: (1) Do patients diagnosed with anxiety and depression have a higher tendency for TC symptoms than people without such diagnoses, even after considering the higher traumatization rates of these patients? And (2) are parental tendencies for TC linked to higher internalizing symptoms of their children independently of the caregivers’ childhood and lifetime trauma experiences? Based on previous studies, we hypothesize that (1) patients diagnosed with anxiety and/or depression will experience more TC symptoms than individuals without these diagnoses (Abiola et al., 2018; Gökyar & Erdur-Baker, 2021; Hansen et al., 2016; Jordan et al., 2019), and (2) parental tendencies for TC will result in higher internalizing symptoms in children (Cho et al., 2021; Dashorst et al., 2019; Snyder et al., 2016; Vreeland et al., 2019).

2. Material and methods

2.1. Study sample

Thirty-five thousand young adults born between 1981 and 1998 were randomly drawn from the Danish Civil Registration System (DCRS) (Schmidt et al., 2014). In Denmark, all citizens are registered in the Danish Civil Registration System by a personal registration number, enabling the linkage of data between the Danish registers and survey data on an individual and de-identified level (Schmidt et al., 2014). For the current study, patients diagnosed with depression, or an anxiety disorder were oversampled through record linkage to ensure adequate power for different group comparisons. Specifically, we obtained register-based data from the Danish National Patients Registry (Lynge et al., 2011), including the Danish Central Psychiatric Register (Mors et al., 2011). The Danish National Patient Registry holds individual-level data on the type of patient contact (i.e. inpatient, emergency room, or outpatient), diagnosis, and date of admission and discharges for all hospital admissions in Denmark. Diagnoses of anxiety (300.09, 300.39, 300.29; F40-F43.1) and depression (296.09, 29.629, 29.809, 300.49, F32-F33) were retrieved based on the international classification of disease versions 8 and 10 (ICD-8/10) codes (World Health Organization, 1965, 1993). Of the randomly drawn young adults, 71.4% of the study population were patients. Of these patients, 11,000 had been solely diagnosed with depression, 10,000 with anxiety, 4,000 had both a diagnosis of depression and anxiety and 10,000 had neither received a diagnosis of depression nor anxiety at the time of recruitment (but could have had other diagnoses). The initial study invitation was sent to this randomly drawn study sample via an electronic secure mail system (eBoks) (Agency for Digital Government, n.d.) used by Danish public authorities. Between June 2017 and January 2019, a total of 34,813 young adults were successfully contacted using eBoks (a national online digital mailbox linked to the population’s Danish personal registration numbers by which people can receive mail from all of Denmark's municipalities, regions, state authorities, and other institutions).

2.2. Measures

We measured the tendency for TC and lifetime trauma in the young adults and those participants who had children were asked to inform on one child’s internalizing symptoms. All measures were completed by adult participants.

2.2.1. Terror catastrophizing

The tendency for terror catastrophizing was measured using the Terrorism Catastrophizing Scale (TCS), a 13-item questionnaire designed to measure the psychological impact of the fear of future terrorism on participants, which was developed based on the Pain Catastrophizing Scale (PCS) (Sinclair & LoCicero, 2007). It measures three constructs: rumination, magnification, and helplessness, giving an overall catastrophizing score (Sinclair & LoCicero, 2007). The questionnaire uses a 5-point Likert scale (i.e. strongly disagree, disagree, uncertain, agree, and strongly agree) (Sinclair & LoCicero, 2007). The TCS has been validated for accuracy and has shown to be an effective measure of participants’ outlook, with a test-retest reliability intraclass correlation (ICC) of 0.89 (Sinclair & LoCicero, 2007).

2.2.2. Lifetime parental trauma

The Trauma History Questionnaire (THQ) is a 24-item self-report questionnaire that inventories experiences with potentially traumatic connotations such as crime, disasters, and assaults (i.e. physical, and sexual). The THQ uses a binary yes/no response format (Mueser et al., 2001). The scale has high interrater reliability, ranging from 0.76–1.0, and test-retest reliability, ranging from 0.47–0.91 (Green et al., 2005).

The Childhood Trauma Screener (CTS) 5-item self-report is derived from the Childhood Trauma Questionnaire (CTQ), and has an internal consistency of α = 0.757 (Glaesmer, 2016). Each of the five items covers one of the five subscales in the CTQ: emotional abuse, physical abuse, sexual abuse, emotional neglect, and physical neglect (Glaesmer, 2016; Spinner & Rudolph, 2019). The CTS is shown to be correlated with the CTQ. Specifically, the correlations of CTS and the respective subscales of the CTQ ranged from r = 0.55 to r = 0.87, and the CTQ has been shown to have an acceptable test-retest reliability, with an ICC of 0.77 (Glaesmer, 2016).

2.2.3. Children’s internalizing symptoms

The Child Behavior Checklist for Ages 6–18 years (CBCL/6-18) filled in by caregivers is a widely used, empirically derived measure to assess children's dimensional psychopathology and adaptive functioning, with a high test-retest stability and good internal consistency (Achenbach, 1991; Achenbach & Edelbrock, 1981). The 113-item scale uses a 3-point Likert scale (not true, somewhat or sometimes true, and very often or always true) given to parents to measure a wide range of child behaviours across the past six months. The CBCL contains ten empirically defined syndrome scales related to psychiatric problems; we used the anxious/depressed subscale as our outcome of interest. The anxious/depressed subscale was shown to have an internal consistency of 0.84 and interrater reliability of 0.68 (Achenbach & Edelbrock, 1981). For standardization purposes, the contacted parents were asked to complete the CBCL for the eldest of their children.

2.3. Covariables

Information on gender and age was obtained for all 35,000 young adults using the Civil Registration System. From the registers on personal labour market affiliation (Thygesen et al., 2011), we retrieved parents’ occupation status as an indicator of socioeconomic status (SES): in the labour force (self-employed or employed), unemployment, sick pay or leave of absence, pension, social security benefit, enrolled in education, and other.

2.4. Ethics

We only included young adults who were not legally incapacitated. According to Statistics Denmark, young adults with a protected address/name were not eligible. Following the Declaration of Helsinki principles, participants were informed that participation in the survey was voluntary and that consent to participate could be withdrawn at any time. The Danish Health Data Authority approved the questionnaire and survey methodology, and approval for the use of data from the Danish registers was granted by Statistics Denmark and the Danish Health Data Authority. The project was registered with the Danish Data Protection Agency (record number 2016-051-000001).

2.5. Theory and calculation

Inverse probability weighting (IPW) (Seaman & White, 2013) was used to limit possible influences of selective survey participation on the associations between the tendency for TC with clinical diagnoses and trauma experiences and its transgenerational effects on children’s internalizing symptoms. Using this approach, estimates were weighted to account for probabilities providing results that could be extrapolated to the whole Danish population in 2018. IPW relies on building a logistic regression model to estimate the probability of being part of the study population based on a selection of variables. The present study estimated the IPW of survey participation using a logistic regression model with sex, age, SES, and parental diagnosis. The Hosmer-Lemeshow test was used to assess model fit. The reciprocal of the predicted probabilities from these models were used as sampling weights to adjust the regression models of interest. IPW was performed using the statistical software SAS.

To address hypothesis 1, we assessed the association of mental health diagnoses as well as lifetime and childhood trauma with TC symptoms in young adults using a generalized linear regression model. Diagnoses were classified into four subgroups: (1) sole lifetime diagnosis of depression; (2) sole lifetime diagnosis of anxiety disorder; (3) lifetime diagnoses of both depression and anxiety; or (4) no lifetime diagnosis of depression nor anxiety. The analyses were adjusted for age, sex, and SES as potential confounders. To test hypothesis 2, focusing on transgenerational effects, the score on the anxious/depressed subscale of the CBCL/6-18 for the children of participants was defined as the major outcome of interest. Using generalized linear regression models, we tested the effect of the parental tendencies for TC on the presence of their children’s internalizing symptoms. As potential confounders, we included adjustments for parental psychiatric diagnosis, lifetime and childhood trauma, parental age, parental sex, and SES. Parental diagnoses were classified into the four subgroups defined above.

3. Results

3.1. Participants

In total, n = 4,175 of the 34,813 invitees completed the whole survey (response rate of 12%). Of the respondents, 1,471 had been solely diagnosed with depression, 1,128 with anxiety, 569 had both a diagnosis of depression and anxiety, and 1,007 had neither a diagnosis of depression nor anxiety at the time of recruitment. A total of 933 participants reported on a child aged between 6 and 18 years (mean age of 8.37, 51% males). Sample demographics by parental diagnosis are shown in Table 1, and mean scores on measures by parental diagnosis are presented in Table 2.

Table 1. Sample demographics by parental diagnosis.

	Diagnosis
	Depression (n = 363)	Anxiety (n = 253)	Anxiety/Depression (n = 102)	No Anxiety/Depression (n = 215)
Age in years, mean (SD)	34.85 (3.0)	34.94 (3.0)	34.55 (3.0)	35.12 (3.0)
Gender
Male	51 (14.0%)	39 (15.4%)	10 (9.8%)	32 (14.9%)
Female	312 (86.0%)	214 (84.6%)	92 (90.2%)	183 (85.1%)
SES
Self-employed	6 (1.7%)	< 5	< 5	< 5
Employed	194 (53.4%)	124 (49.0%)	37 (36.3%)	164 (76.3%)
Unemployed	10 (2.8%)	6 (2.4%)	< 5	8 (3.7%)
Leave of absence	12 (3.3%)	9 (3.6%)	< 5	< 5
Pension	12 (3.3%)	7 (2.8%)	< 5	< 5
SSB	31 (8.5%)	23 (9.1%)	17 (16.7%)	15 (7.0%)
Enrolled in education	88 (24.2%)	74 (29.2%)	38 (37.3%)	14 (6.5%)
Other	10 (2.8%)	8 (3.2%)	< 5	6 (2.8%)

Abbreviations: SSB, social security benefit; SD, standard deviation.

Table 2. Mean scores and standard deviations on measures by parental diagnosis.

	Diagnosis
Variable	Depression (n = 363)	Anxiety (n = 253)	Anxiety/Depression (n = 102)	No Anxiety/Depression (n = 215)
TCS	36.80 (6.97)	37.70 (7.55)	38.49 (7.21)	36.41 (6.14)
THQ	6.58 (3.60)	6.70 (3.77)	6.69 (3.49)	4.77 (3.06)
CTQ	8.19 (2.83)	8.53 (3.30)	8.54 (3.385)	6.74 (2.50)
CBCL	24.76 (5.59)	24.08 (5.18)	24.96 (5.58)	22.92 (4.38)

Abbreviations: TCS, Terrorism Catastrophizing Scale; THQ, Trauma History Questionnaire; CTQ, Childhood Trauma Questionnaire; CBCL, Parent Child Behavior Checklist.

3.1.1. Attrition analysis

The respondents were slightly older (31.3 years vs. 31.2 years, p < .05) and less likely to receive social security benefits (18.6% vs. 19.6%, p = .04) compared to the non-respondents. No other differences were observed.

3.2. Terror catastrophizing by diagnosis and trauma

Among the 4,175 respondents, the tendency for TC was significantly higher among respondents in subgroups 1–3, with any anxiety or depression diagnoses, (β = 0.05, p = .003) than subgroup 4, the control, where β represents the regression coefficient. Specifically, TC was significantly more frequent in respondents solely diagnosed with anxiety (β = 0.10, p < .001) and in respondents diagnosed with depression and anxiety (β = 0.07, p = .012), but not in respondents solely diagnosed with depression (β = 0.02, p = .27) compared to controls. TC was also significantly increased with the number of lifetime traumata respondents had experienced by the THQ (β = 0.10, p < .001). In contrast, as measured by the CTQ, childhood trauma was not significantly associated with the tendency for TC (β = −0.02, p = .33).

3.3. Parental tendencies for terror catastrophizing and children’s internalizing symptoms

In the subsample of 933 parents, internalizing symptoms were significantly higher in children of parents who had a tendency for TC (β = 0.10, p = .002). Internalizing symptoms were also higher in children of parents with any anxiety or depression diagnosis (β = 0.07, p = .043) or increased with the number of lifetime traumata parents had experienced (β = 0.11, p = .005). At the same time, only a trend was observed for parental childhood trauma (β = 0.07, p = .071). Parental tendencies for TC remained a significant predictor of children’s internalizing symptoms (β = 0.09, p = .006) in the full model, adjusting for parental diagnosis and lifetime and childhood trauma. The results of all models are shown in Table 3.

Table 3. Linear regression models predicting child internalizing problems.

	Outcome: Child internalizing problems
	β	SE	p-value
Model 1
Age	−0.055	0.058	.94
Gender	−0.020	0.49	.54
SES	−0.23	0.43	<.001
Terror catastrophizing	0.10	0.024	.002
Model 2
Age	−0.057	0.057	.43
Gender	−0.00026	0.48	.99
SES	−0.15	0.47	.002
Diagnosis	−0.068	0.42	.043
Lifetime trauma	0.11	0.058	.005
Childhood trauma	0.069	0.066	.071
Model 3
Age	−0.059	0.057	.072
Gender	−0.0083	0.48	.80
SES	−0.13	0.47	.003
Terror catastrophizing	0.089	0.024	.006
Diagnosis	−0.066	0.41	.047
Lifetime trauma	0.10	0.058	.009
Childhood trauma	0.070	0.066	.068

SES = Socio-economic status.

4. Discussion

Previous studies suggested that individuals diagnosed with anxiety and depression are more likely to have a tendency for TC (Abiola et al., 2018; Gökyar & Erdur-Baker, 2021; Hansen et al., 2016; Jordan et al., 2019). However, it was unclear whether the relationship was due to diagnoses alone or the greater traumatization rates seen in individuals diagnosed with anxiety and depression. Thus, the current study was designed to better understand the relationship between the diagnoses and higher TC rates and to examine the impact of parental tendencies for TC on children’s internalizing symptoms by addressing two research questions: (1) Do patients diagnosed with anxiety and depression experience a higher tendency for TC than people without such diagnoses, even after considering the higher traumatization rates of these patients? And (2) are parental tendencies for TC linked to higher internalizing symptoms of their children independently of the parents’ childhood and lifetime trauma experiences?

Based on our first research question and previous studies investigating TC (Abiola et al., 2018; Gökyar & Erdur-Baker, 2021; Hansen et al., 2016; Jordan et al., 2019), our first hypothesis was that patients diagnosed with anxiety or depression would show a significantly higher tendency for TC than individuals who are not diagnosed. Our hypothesis was partially supported by our results, which suggest that patients diagnosed with anxiety disorders and patients with comorbid anxiety and depression reported slightly more TC symptoms when compared to undiagnosed individuals. These results align with Abiola et al. (2018), who observed a moderate correlation between incidence rates of diagnoses of anxiety or depression and TC. Contrary to our hypothesis, the current study also suggests that patients diagnosed with depression only experience a similar amount of TC as those without any diagnosis (Abiola et al., 2018; Gökyar & Erdur-Baker, 2021; Hansen et al., 2016; Jordan et al., 2019). This discrepancy is likely due to the fundamental differences between clinical conceptions of depression and anxiety, and how they relate to TC. While the comorbidity of depression and anxiety disorders is remarkable (Murphy et al., 2004), depression is primarily characterized by feelings of sadness, emptiness, and irritability, and not by excessive fear or anxiety, which are the characteristics of anxiety disorders (American Psychiatric Association, 2013). Our results suggest that anxiety symptoms are likely the primary cause of increased tendency to TC in those with comorbid depression and anxiety in contrast to patients solely diagnosed with depression.

Based on our second research question and previous studies investigating generational trauma (Cho et al., 2021; Dashorst et al., 2019; Snyder et al., 2016; Vreeland et al., 2019), our second hypothesis was that parental tendencies for TC would result in higher internalizing symptoms of their children. Our results support our second hypothesis and suggest that parental tendencies for catastrophizing were associated with a small increase in internalizing symptoms in children even after accounting for parental diagnosis as well as the parents’ childhood and lifetime trauma. While lifetime parental trauma was also associated with more internalizing symptoms in children, parental childhood trauma was not associated with increased internalizing symptoms in their children. These results are likely due to cumulative trauma over an individual’s lifespan, which has been shown to have a more significant impact on internalizing symptoms than childhood trauma alone (Abraham et al., 2022; Overstreet et al., 2017). Previous research has shown that the children of parents with internalizing symptoms are significantly more likely to develop internalizing symptoms themselves (Ginsburg et al., 2021; Hirshfeld-Becker et al., 2008; Micco et al., 2009). These previous findings could explain why parents who experience more lifetime traumata are more likely to have internalizing symptoms, and therefore their children are more likely to have internalizing symptoms as well.

Our results contrast with previous research by Cho et al. (2021), who used multiple regression to analyze the relationships between parental trauma exposure, internalizing symptoms (i.e. anxiety and depression), and parental stress. Like the current study, their results suggest that when parental stress is moderate to high, there is a significant relationship between parental trauma exposure and anxiety. However, their results suggest that parental trauma exposure was not significantly associated with children’s symptoms of depression. The discrepancy between the results of the current study and Cho et al.’s (2021) work may be due to differences in methodologies, with Cho et al. (2021) using two separate child-report measures for internalizing symptoms (i.e. Children’s Depression Inventory and the Multidimensional Anxiety Scale for Children) and the current study relying solely on the parent-reported CBCL for internalizing symptoms in general. Previous work by Olino et al. (2018) suggests differences in measurements of internalizing symptoms when comparing the reports of parents and their children, which may account for the differing results. It may also be due to the differences in sample size and composition. Since the sample size of the current study was so large, it is possible that a distinction was detectable that was not possible in a study with a smaller sample. Further, Francis (2014) demonstrated that parent anxiety could influence parent perceptions of child anxiety. Taking into account the effects of TC on parental anxiety, this could be another contributor to the contrasting results with Cho et al. (2021). Additionally, the difference may be due to the different ethnicities and nationalities of the samples, as the history of trauma can differ between ethnic groups and countries.

In Denmark, the population of focus in this study, major terror attacks that received widespread news coverage in recent memory include the 2015 Copenhagen shooting, and the 2011 Cartoon Affair (Hervik, 2018). Yet also, attacks in other countries that received widespread media coverage impacted the mental health of the Danish population. For example, Hansen et al. (2017, 2016) found that the Danish people were affected by the Breivik attack in Norway and the 9/11 attack in the U.S., with documented increases in trauma and stress-related disorders in the year following the attack. Yet the Danish population scored lower on the TCS than the U.S. general population (Sinclair & LoCicero, 2007). Shared genetic effects could add an additional layer of complexity, though there is currently limited evidence for the involvement of genetics in the inter-generational impact of TC (Ahmadzadeh et al., 2019).

4.1. Strengths and limitations

A strength of the current study is that it fills two crucial niches in the literature. First, to the authors’ knowledge, it is the first study to parse apart the relationship between diagnoses and traumatization rates on the tendency for TC. It is also novel in exploring the transgenerational impact of TC tendencies. Additionally, the large sample size of the current study is a methodological strength. Due to the large sample collected for the current study, all statistical analyses are powerful, providing high confidence in the conclusions drawn from the results.

A limitation of the current study is that it relied solely on parental reports of internalizing symptoms in children. As Olino et al. (2018) suggest, having a one-sided report of internalizing symptoms can be potentially biased due to the differences between child-report and parent-report data. Notably, it has also been found that parents who experience anxiety are more sensitive to their children’s behaviour which may lead to possible over-reporting (Francis, 2014). Additionally, measures of parental trauma were self-reported and retrospective, making it difficult to ascertain the accuracy of their responses. While the current study focused on lifetime diagnoses, it remains unclear how much the observed association was actually due to participants’ current psychopathology. Finally, though very large, the current study's sample may not be representative. The attrition analysis showed small but significant differences between participants who completed the study and those who did not. Although we adjusted for these differences via covariates, the results drawn from the current study may be limited in their generalizability. Additionally, the response rate for the survey was very low (i.e. 12%), suggesting a potential lack of representativeness (Pedersen & Nielsen, 2016).

4.2. Future directions and impact

The current study helps elucidate the relationships between the tendency for TC, trauma, and internalizing symptoms. Future studies should examine the characteristics of TC in association with clinical diagnoses in greater detail. For example, exploring the potential moderating role of parental stress on TC tendencies (Cho et al., 2021) and its impact beyond internalizing disorders, as research has shown parental stress could have a mediating role for children’s externalizing behaviours (Pei et al., 2019). In addition, this study highlights the likelihood of patients diagnosed with anxiety alone or comorbid to depression having a higher tendency for TC, which might indicate that patients process terror events differently. TC has been shown to trigger physiological stress responses resulting in higher pulse rates (Shenhar-Tsarfaty et al., 2015). Thus, an intervention targeting terror fear might not only alleviate mental health symptoms but also potential cardiovascular issues as a result of the stress response system being in overdrive. However, TC may not be solely limited to anxiety and depression; considering the findings of the current study, future studies should investigate the association of TC symptoms with other diagnoses, especially those commonly comorbid with anxiety, to better understand the scope of patients that might benefit from an intervention targeting TC. Given that TC has an impact on children’s mental health independent of the parental diagnosis, considering preventative measures in clinical care is imperative in order to limit the transgenerational impact of TC. Parents should be able to learn more adaptive coping mechanisms, so they can function as role models for their children helping them to overcome the negative effects of terrorism on their health.

4.3. Conclusions

Findings of the current study contribute to the clinical understanding of TC tendencies. Our findings reveal that patients diagnosed with anxiety alone or comorbid with depression are significantly more likely to have a tendency for TC than undiagnosed individuals. These findings can inform clinical practices to account for the potential of patients to exhibit TC tendencies and being more impacted by traumatic events. The current study also suggests that parental tendencies for TC can impact children's internalizing symptoms, which can inform the design of novel preventative interventions for the whole family.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Due to ethical restrictions, the supporting data is private and unavailable to share.

Additional information

Funding

This work was supported by the Mental Health Services Capital Region Denmark and the Canadian Institute for Health Research (CIHR) Canadian Research Chairs (CRC) stipend [under award number 1024586]; Patient-Oriented Research: Early Career Investigator Project Grant [under grant number PJM 177968]; and Canadian Foundation for Innovation (CFI) John R. Evans Leaders Fund (JELF) [under grant number 38835].