Post-traumatic stress in war veterans and secondary traumatic stress among parents of war veterans five years after the 2014 Israel-Gaza military conflict

ABSTRACT

Secondary traumatic stress (STS) has been studied in therapists, spouses, and mainly in children of traumatised individuals. To date, the relationship between children’s posttraumatic stress disorder (PTSD) symptoms and their parents’ mental health outcomes have been understudied, and specifically, long term STS symptoms of parents of war veterans were not investigated. The current study examined PTSD symptoms among veterans of the 2014 Israel-Gaza war and STS among their parents, five years after the war. The control group consisted of veterans from combat military units who were on active duty at the time of the war but did not actively participate in the war (stand-by units) – providing a natural experiment condition. We found that PTSD symptoms were almost twice as high in the directly active war veterans (DAV, N = 32) group compared to the indirectly active war veterans (IAV, N = 26) group. Results showed that mothers had higher STS symptoms in general, and DAV PTSD symptoms correlated with their fathers STS symptoms. The current study provides novel evidence for: (a) subclinical PTSD symptoms in war veterans 5 years after the war, and (b) transmission of trauma from war veterans to their parents. The overall negative effect of sending a child to war on the parents are also discussed.

HIGHLIGHTS

• The current study examined post-traumatic stress symptoms among undiagnosed war veterans of the 2014–2014 Israel-Gaza Military Conflict compared to matched control who were on active military duty at the same time but did not actively participate in the war. We found higher post-traumatic stress symptoms in the veterans who actively participated in the war, roughly five years after the war.

• Parents of veterans who actively participated in the war exhibited higher secondary traumatic stress compared to parents of veterans who did not actively participate in the war. This is especially interesting given that parents of all veterans were not aware of their whereabouts during the war. Overall, mothers exhibited higher secondary traumatic stress compared to fathers. However, fathers were more ‘in-sync’ with their sons’ traumatic experience as evident by a significant correlation between the war veterans’ post-traumatic stress and the fathers’ secondary traumatic stress symptoms.

El estrés traumático secundario (STS por sus siglas en inglés) ha sido estudiado en los terapeutas, cónyuges y principalmente en hijos de individuos traumatizados. Hasta la fecha, la relación entre síntomas de trastorno de estrés postraumático (TEPT) en niños y las consecuencias de salud mental de sus padres han sido poco estudiadas y específicamente, los síntomas de STS a largo plazo de los padres de veteranos de guerra no se han investigado. El estudio actual examinó los síntomas de TEPT entre veteranos de la guerra Israel-Gaza del 2014 y STS entre sus padres, cinco años después de la guerra. El grupo control estaba formado por veteranos de unidades militares de combate que estaban en servicio activo en el momento de la guerra, pero no participaron activamente en la guerra (unidades de reserva) proporcionando una condición de experimento natural. Encontramos que los síntomas de TEPT eran casi el doble en el grupo de veteranos de guerra directamente activos (DAV, N = 32) comparado con el grupo de veteranos de guerra indirectamente activo (IAV, N = 26). Los resultados mostraron que las madres tenían síntomas de STS más elevados en general y síntomas de TEPT del DAV se correlacionaron con los síntomas de STS de sus padres. El estudio actual proporciona evidencia novedosa para: (a) síntomas de TEPT subclínicos en veteranos de guerra 5 años después de la guerra y (b) transmisión del trauma de los veteranos de guerra a sus padres. Se discute tambien el efecto negativo general de enviar un hijo a la guerra en los padres.

二次创伤应激（STS）已在治疗师、配偶以及主要是受创伤者子女中进行了研究。迄今为止，儿童创伤后应激障碍 (PTSD) 症状与其父母心理健康结果之间的关系尚未得到充分研究，特别是还没有对退伍军人父母的长期 STS 症状进行调查。目前的研究考查了 2014 年以色列-加沙战争退伍军人的PTSD症状以及战后五年后他们父母的 STS 症状。对照组由战时现役但未积极参战的作战部队退伍军人（待命部队）组成，这提供了天然的实验条件。我们发现直接现役退伍军人组 (DAV, N=32)的 PTSD 症状几乎是间接现役退伍军人 (IAV, N=26) 组的两倍。结果显示，母亲总体上有较高的 STS 症状，而 DAV PTSD 症状与父亲的 STS 症状相关。目前的研究为以下方面提供了新的证据：(a) 战后 5 年后退伍军人的亚临床 PTSD 症状，以及 (b) 退伍军人向其父母传播创伤。还讨论了将孩子送去战争对父母的总体负面影响。

KEYWORDS:

• Post-traumatic stress disorder (PTSD)
• anxiety
• secondary traumatic stress (STS)
• war veterans
• transmission of trauma

PALABRAS CLAVE:

• Trastorno de Estrés Postraumático (TEPT)
• Ansiedad
• Estrés traumático secundario (STS)
• Veteranos de guerra

創傷後應激:

• 创伤后应激障碍（PTSD）
• 焦虑
• 二次创伤应激（STS）
• 退伍军人。

Secondary Traumatic Stress (STS) is a term used to describe the consequent behaviours and emotions resulting from exposure to a traumatising event which occurred to a person the individual is close to (Figley, 1995). Figley and McCubbin (1983) initially termed this phenomenon secondary catastrophic stress reaction, emphasising emotional upset, exhaustion, vigilance, and avoidance that commonly characterise this condition. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5; American Psychiatric Association, 2013) has acknowledged secondary traumatisation as one possible diagnostic criterion for post-traumatic stress disorder (PTSD). Importantly, aside from the difference in the triggering circumstances of the disorder, the symptoms of STS are believed to be identical to those of PTSD (American Psychiatric Association, 2013). Thus, STS and PTSD might be very similar if not identical. While STS has been studied mainly in children or spouses of traumatised individuals, the current study focuses on STS in parents of war veterans.

That trauma can be transferred to spouses, therapists, and mainly children of individuals who experienced a traumatic event, has been demonstrated in several seminal investigations (Dinshtein et al., 2011; Weinberg et al., 2016). One study (Tehrani, 2007) found that over 60% of therapists who treated traumatised clients experienced STS symptoms, including a feeling that they will not be able to recover from their exposure to the traumatic event. Within families, some studies have focused on transmission of trauma from one spouse to the other (Solomon et al., 1992), while most investigations focused on the transmission of trauma from parents to their children. For example, recent studies reported STS symptoms in adult children (Shrira, 2015), and even grandchildren (Letzter-Pouw et al., 2014) of Holocaust survivors, decades after the Holocaust. Similarly, Zerach and Aloni (2015) found significant STS symptoms among children of former prisoners of war (see also Zerach et al., 2017). Furthermore, the research on the mechanism behind the transmission of trauma is also mainly focused on how trauma is transferred from parents to offspring (before and after the child is born). Several studies suggested that maternal exposure to stress and trauma during pregnancy might have negative physiological and psychological effects on the offspring (O'Connor et al., 2013; Shrira, 2015). Recently, Yehuda and Lehrner (2018) conducted a comprehensive review that emphasised the in-utero changes that might be mediated by maternal trauma-related symptoms. This accumulating evidence emphasises the notion that emotionally charged relationships with a traumatised person may lead to the transmission of trauma. It also suggests that more research is required to fully understand how trauma is transmitted.

While the studies reviewed above, which focus on the transmission of trauma within the family, focused on how trauma is transmitted from parents (primarily mothers) to their offspring, less attention has been given to the effect of trauma survivors’ PTSD on their parents’ STS symptoms, and almost no research has been done on STS symptoms in parents of war veterans. A recent meta-analysis concluded that parents of children who experienced a single-incident acute trauma are more likely to develop STS symptoms (Wilcoxon et al., 2021). With respect to more complex trauma, one study found that foster parents are more prone to have STS, and that the amount of exposure to the traumatic experiences of the traumatised children was an important factor in the development of STS (Whitt-Woosley et al., 2020). However, in that study, children’s PTSD symptoms were only assessed by the parents’ ratings which limits the ability to draw conclusions on the connection between the severity of the child’s trauma and the development of STS among the foster parents. Another study found that parents of sexually abused children experience greater overall emotional distress, poorer family functioning, and lower satisfaction in their parental role (Manion et al., 1996), although this study did not measure STS symptoms directly nor did it investigate the connection between the child’s PTSD and the parents’ STS. Importantly, in this study, the researchers found that mothers of a sexually abused child developed higher levels of distress, compared to the fathers (Manion et al., 1996). We will further discuss this finding in the Discussion section below. With respect to veterans, one study found that parents of Dutch peacekeeping soldiers did not exhibit higher levels of STS, in comparison to partners of these soldiers. This study suggests that traumatic stress of young adults affects their spouses more than their parents (Dirkzwager et al., 2005). However, without a proper control group, it is impossible to know whether the parents of these veterans exhibited higher levels of STS in general. If trauma is also transferred from a traumatised veteran to her/his parents, a direction that has been mostly overlooked in the literature, it might shed new light on the mechanisms through which trauma might be transferred.

Neglecting the effect of traumatised veterans on their parents’ well-being, is an outstanding gap in the literature, which is especially noticeable given that young adults are more likely to actively participate in military conflicts while their parents anxiously await their return. While we have learned relatively more about the effect of war on the mental well-being of soldiers, veterans, spouses, children, and therapists (e.g. Canfield, 2005; Dagan et al., 2016; Tehrani, 2007), we know very little about the psychological effect of these traumatic situations on the parents of war veterans. Not only should such information be heavily considered as part of the ‘cost of war’, but it would also have very specific implications for countries mental health policies regarding parents of war veterans. Importantly, just as traumatised parents return to live with their children and spouses, young adults often return to live with their parents after the traumatising experience, at least for a few years. Given that parents may be especially attuned to their children’s negative experiences, the exposure of a child’s traumatic symptoms or traumatic stories may serve as an additional stressor to parents on top of the already stressful war. Thus, parents of war veterans might be an overlooked at-risk group for the development of STS symptoms or even PTSD.

The 2014 Israel-Gaza conflict provides us with a unique opportunity to investigate STS among parents of war veterans. This is mainly because deploying soldiers on various fronts (war vs. non-war) was mostly random, providing us with the unique conditions for a natural experiment. The 2014 Israel-Gaza war was launched on July 8th, 2014 in the Gaza strip (a Palestinian territory located on the border of Israel and Egypt) and lasted 7 weeks. Thousands of Israeli active soldiers, most of them between the ages of 18 and 22, participated in this war. As a direct result of the fighting, 70 Israeli soldiers, 5 Israeli civilians, approximately 1,000 Palestinian combatants, and approximately 1,000 Palestinian civilians were killed (469 Israeli soldiers and a few thousand Palestinian combatants were wounded; all numbers are based on formal publications from both sides; Ministry of Foreign Affairs, 2015). Its length and extremely high cost in human lives, made the 2014 Israel-Gaza war one of the toughest military clashes in the Middle East in the last decades. To achieve the current study goals, we measured PTSD symptoms in Israeli war veterans who were enlisted in active military duty as combat soldiers during the 2014 Israel-Gaza war and STS symptoms in their parents. In the ‘directly active veterans’ (DAV) group, participants’ were directly involved in the war, while in the ‘indirectly active veterans’ (IAV) group participants served in ‘standby’ units and were, therefore, indirectly involved in the war.

The main goals of the current study were (a) to provide evidence for elevated PTSD symptoms in war veterans five years after the war ended, and (b) to provide novel evidence for STS symptoms in parents of war veterans. As a rule, during times of ‘limited conflict’ (a military operation in which only a relatively small portion of the army is participating) the Israeli Defense Forces ensures that some combat units sit out the combat and remain on standby. Essentially, apart from specialised units, the combat units who participate in the war and the ones who are on standby, are largely equivalent. Furthermore, combat units that do not actively participate in the war are put on a high-alert standby, prepared to join the fighting at a moment’s notice, and support the war effort in various ways. Families of both such directly and indirectly (standby) active soldiers, are almost always not aware of the precise whereabouts of their soldier child. Therefore, although we did not (and could not) randomly allocate participants into DAV and IAV groups, participants were in actuality allocated into groups by virtue of a process that resembles a natural experiment. We hypothesised that: (a) DAV and their parents would exhibit higher levels of PTSD and STS scores (respectively) compared to IAV and their parents, (b) veterans PTSD scores will correlate with parents STS scores, indicating that the veteran PTSD has ‘transferred’ to the parent. In addition, we wanted to investigate the differences between fathers and mothers in their response to war-related trauma of their children. Given that this kind of an examination has not been conducted yet and a clear hypothesis could not be founded (see Discussion section), we decided to test our hypotheses on fathers and mothers separately at the exploratory level. Finally, as mentioned above, we aimed to investigate the effect of war on the general population of veterans and not necessarily on those who seek help for PTSD. Thus, we focused our investigation on non-diagnosed war veterans.

1. Method

1.1. Participants

One-hundred and sixty-eight participants (56 families – veterans, mothers, and fathers) took part in the study: the ‘Directly Active Veterans’ (DAV) group was comprised of thirty young Israeli men between the ages of 23 and 28 and their parents, while the ‘Indirectly Active Veterans’ (IAV) group was comprised of twenty-six young Israeli men between the ages of 23 and 29 and their parents. Eleven fathers and seven mothers did not complete the study procedures. Participants in the DAV group were present in the war zone (physically within the Gaza Strip) for at least 48 consecutive hours during the 2014 Israel-Gaza war (between the dates: July 8th, 2014, and August 26th, 2014). Participates in the IAV group were also on active military duty during these dates but their units were stationed near the war zone on standby and they did not cross the border. All veterans were between the ages of 18 and 24 at the time of the war and none were exposed to any other war during their military service. Exclusion criteria included veterans, or at least one of their parents, reporting: (a) experiencing a major traumatic event (such as war, terror attack, life threating accident, sexual assault, any other immediate threat to their life, or any event that led to acute stress disorder; measured by the Stressful Life Events Screening Questionnaire; SLESQ; Goodman et al., 1998) either before or after the 2014 Israel-Gaza war or (b) having Schizophrenia or bipolar disorder. In addition, participants were excluded if they had a formal diagnosis of PTSD¹ or if they had a sibling who actively participated in the 2014 Israel-Gaza war or in a different war. None of the participants were physically injured or required medical attention during the war. Participants received a token monetary payment (approximately $25) for their participation. The sample was recruited via social media and specifically via groups of university students. Ads called for individuals who were in active military service during the war to get in touch with the researchers via email or phone. Participants who reached out underwent a very quick phone interview to ensure they met the study’s inclusion criteria and were then given the study’s instructions. At this point, no further information on the study’s aims and goals was disclosed.

A power analysis using G × Power 3.1 (Faul et al., 2007) was carried out based on the effect size reported by Zerach and Aloni (2015). In that study, that compared STS between children of ex-POWs and control children, the authors reported ${\eta }_P^2$ = .15 for the two-way interaction between group (ex-POW vs. control) and report-type (2-levels within-subject factor). Based on this effect size, the current sample allowed for examination of group differences in PTSD and STS symptoms, and of the two-way interaction between group (between-subject) and gender of the parent (within-subject), at a power >90% with a Type 1 error (α < 0.05).

1.2. Measures

The Stressful Life Events Screening Questionnaire (SLESQ; Goodman et al., 1998) was used to eliminate the possibility that the child or parents experienced other major traumatic events either before or after the 2014 Israel-Gaza war. The SLESQ is a 13-item self- report measure that addresses 11 specific and 2 general categories of traumatic events. The SLESQ had an excellent test-retest reliability (0.89) and good test-interview validity (0.77; Goodman et al., 1998). Participants were instructed to report only events not directly related to the 2014 Israel-Gaza war.

The PTSD Symptom Levels Scale (PSL-5; Gil et al., 2015) is a 20-item self-report questionnaire based on the DSM-5 diagnostic criteria for PTSD. The scale is divided into four clusters: intrusion, avoidance, negative alterations, and alterations in arousal. This questionnaire has been validated on individuals who live around the Gaza strip and has shown good content validity, good internal reliability (r = .63 to r = .91), and excellent reliability (Cronbach’s $\alpha$= .94; Gil et al., 2015; Cronbach’s $\alpha$ in the current study = .91). War veterans were asked to refer to the 2014 Israel-Gaza war as the criterion A and answer the questions accordingly.

The Secondary Trauma Questionnaire (Figley, 1995; altered by Motta et al., 1999) was used to measure STS caused by terrorist attacks. The questionnaire refers to different clusters of PTSD as defined by DSM-5, while asking about another person’s experience (for example: ‘I have flashbacks [images or obscure memories] that are related to his difficulties’, ‘I experience invasive, unwanted thoughts about his difficulties’, ‘I am startled easily’). The questionnaire has good internal consistency and correlates significantly with known measures of trauma (Motta et al., 1999). The questionnaire has good internal reliability (Cronbach’s $\alpha$= .88; Shrira, 2015; Cronbach’s $\alpha$ in the current study = .87). Parents of war veterans were asked to ‘keep the 2014 Israel-Gaza war in mind when replying’.

1.3. Procedure

The study was approved by the Hebrew University of Jerusalem’s Ethics Committee (protocol #190119). Data was collected between April 2019 and March 2020. After signing an informed consent form, participants and both their parents were asked to complete a full demographic questionnaire and the SLESQ to exclude other traumatic events. Next, all war veterans completed the PSL-5 and all parents completed the Secondary Trauma Questionnaire, referring to the 2014 Israel-Gaza war. Participants were asked to complete all questionnaires thoughtfully and thoroughly in a single session, without disclosing their responses to their family members before all participating family members completed the study.

1.4. Statistical methods

To assess for potential differences between the groups on demographic and clinical characteristics (age, years of education, PTSD (PSL-5) scores), independent sample t-tests were conducted with group (DAV vs. IAV) as a between-subject factor. To investigate STS symptoms, we carried out a two-way mixed-model ANOVA on The Secondary Trauma Questionnaire scores, with group as a between-subject factor and parent’s gender (mother vs. fathers) as a within-subject factor. Next, to investigate the correlation between veterans’ PTSD and their parents STS scores, we conducted Pearson correlations between veterans’ PTSD and their father STS scores and between veterans’ PTSD and their mothers STS scores, in both the DAV and IAV groups. The differences between the correlations were investigated using Fisher’s Z-test.

2. Results

Demographic and clinical characteristics of both groups are presented in Table 1. The DAV exhibited significantly higher PTSD symptoms than the IAV, t(54) = 2.08, p = .043, Cohen’s d = 0.557. The two-way mixed model ANOVA revealed a main effect for gender, F(1, 39) = 10.54, p < .01, ${\eta }_P^2$ = .21, indicating higher STS symptoms for mothers compared to fathers, a main effect for group, F(1, 39) = 4.58, p = .038, ${\eta }_P^2$ = .11, indicating higher STS symptoms for the parents of the DAV group compared to the parents of the IAV group, but no group by gender interaction, F(1, 39) = 0.19, p = .66, indicating that the differences between the DAV and IAV groups did not differ between fathers and mothers.

Table 1. Sample characteristics.

Group	Age (years)	Years of Education	PSL-5
Veterans
DAV	25.5 (1.23) [24–28]	12.6 (1.23) [12–15]	7.2 (6.7) [1–23]
IAV	24.3 (1.28) [23–29]	12.2 (0.8) [12–15]	3.92 (4.6) [1–17]
Mothers			STS
DAV	56 (5.2) [49–67]	16 (2.4) [12–21]	28.6 (8.6) [20–55]
IAV	54.9 (4.6) [43–66]	15.6 (2) [12–18]	26.1 (6.7) [20–43]
Fathers
DAV	58.1 (6.05) [49–72]	15.5 (3) [12–21]	25.5 (7.7) [20–51]
IAV	57.2 (3.8) [52–65]	16 (2.7) [12–21]	21.57 (2.2) [20–26]

Note: Mean, (SD), and [range] for scores on demographics and clinical variables for Directly active veterans’ group (DAV) vs. indirectly active veterans’ group (IAV). PSL-5 – The PTSD Symptom Levels Questionnaire (PSL-5; Gil et al., 2015). STS – Secondary Trauma Questionnaire (Motta et al., 1999).

The correlation analysis revealed that in the DAV group, veterans’ PTSD level was significantly correlated with their fathers’ STS scores, r(23) = .493, p = .014 (see Figure 1), but not with their mothers’ STS scores, r(23) = .212, p = .308. In the IAV group, veterans’ PTSD levels did not correlate with either their fathers’ STS scores, r(25) = .093, p = .93 or their mothers’ STS scores, r(25) = −.021, p = .922. We carried out a Fisher’s Z-test to compare the difference between the DAV and IAV groups in the correlations between veterans’ PTSD levels and fathers STS levels. The difference was significant (Z = 1.91, p = .043), indicating that the correlation in the DAV group was larger than the correlation in the IAV group.

Figure 1. Results of the correlation analysis. Correlation between post-traumatic stress disorder (PTSD) symptoms (measured by the PTSD Symptom Levels Questionnaire – PSL-5) of the directly active war veterans (DAV) and their fathers’ Secondary Traumatic Stress (STS) scores (as measured by the Secondary Trauma Questionnaire). Pearson’s r = .493, p = .014.

3. Discussion

The current study is the first to investigate Secondary Traumatic Stress (STS) symptoms in parents of directly active war veterans (DAV) compared to veterans who did not actively participate in the war (IAV). Veterans in both groups were on active military duty during the 2014 Israel-Gaza military conflict and served in very similar military units – providing us a natural experimental design. Veterans in the DAV group exhibited PTSD symptoms almost twice as high as veterans in the IAV group, even roughly five years after the war. In addition, our findings indicate that STS was more prevalent among parents of DAV compared to parents of IAV. Mothers in both groups had higher STS symptoms than fathers, with no interaction between the gender of the parent and group. That parents of DAV had higher levels of STS than parents of IAV is especially interesting given that both DAV and IAV were on active military duty during the war and their parents were not always aware of their whereabouts, hence it is reasonable to assume that parents of IAV also experienced high levels of stress and uncertainty. Thus, the effect observed in the current study could not be fully attributed to the stressful experience of sending a child to war. Finally, we also looked at the correlations between veterans’ and parents’ symptoms. In the DAV group, but not in the IAV group, the results indicated a positive correlation between veterans’ PTSD symptoms and their fathers’ STS symptoms. Such a correlation was not observed in mothers. Taken together, these findings indicate that while mothers exhibited higher STS symptoms in both groups of veterans, fathers exhibited high symptoms mainly when their sons actively participated in the war and exhibited PTSD symptoms after the war.

The results of the current study are consistent with previous findings regarding the transference of trauma and stress within the family (Shrira, 2015; Solomon et al., 1992; Weinberg et al., 2016) and go beyond them by providing novel evidence to suggest that trauma might also be transferred from war veterans to their parents. As mentioned in the Introduction, only very few studies have investigated STS symptoms in parents of veterans (Manion et al., 1996; Whitt-Woosley et al., 2020; Wilcoxon et al., 2021) and none focused on war veterans compared to a control group of veterans who did not participate in war. For example, one study on veterans (Dirkzwager et al., 2005) reported no traumatic effect in parents of adult veterans and concluded that transference of trauma is less prominent in adult children. However, the veterans in that study did not actively participate in a war and the study lacked a proper control group. Our results, with actual war veterans, suggest otherwise. We found clear evidence for the transmission of trauma from adult children who participated in the war, to their parents. Furthermore, the effect reported in the current study suggests that although military service per se might lead to some PTSD symptoms and to parents’ STS, active participation in war has a significantly stronger effect on both the veterans and their parents.

Most studies that investigated the transmission of trauma from children to parents did not analyse the differences between mothers and fathers (e.g. Dirkzwager et al., 2005). Of the few studies that did investigate this factor, some reported no differences between mothers and fathers (Manion et al., 1996) while others reported higher levels of STS in mothers compared to fathers (Wilcoxon et al., 2021). Different explanations have been given to why mother tend to be more vulnerable to STS. One option is that mothers are simply more prone to develop STS due the fact that mothers are often the primary caregivers and/or due the fact that women are more prone to develop PTSD (Tolin & Foa, 2002). Another option is that the differences between mothers and fathers are contingent upon their ability to relate to the specific trauma. For example, in the study by Manion et al. (1996), mentioned in the Introduction, the researchers reported that mothers of sexually abused children reported higher anxiety and distress than did the fathers. The results of the current study support both notions. While mothers in the current sample had generally higher STS symptoms, the correlation between veterans’ PTSD and parent’s STS symptoms was only significant in fathers of the DAV group. The latter might be specific to war trauma, particularly given that all veterans in the current study were males and that men, especially when the parents in the current study were soldiers, are more exposed to military culture and combat units. In other words, fathers’ symptoms might be more ‘in sync’ with their sons’ traumatic military experience, as they are familiar with military service and with war-related experiences. Although more research is needed, our findings, taken together with those of Manion and colleagues’ study on parents of sexually abused children, suggest that the ability to relate to the specific experience, plays a significant role in the transmission of trauma. Further research needs to be conducted to investigate what underlying mechanisms cause the difference between secondary traumatisation among mothers and fathers and whether the observed differences between fathers and mothers in current study are specific to war-related trauma and the familiarity of one parent with the specific situation, or whether they might be generalised to other traumas as well (of course, both suggestions could be true to some extent).

A very important finding of the current investigation is that DAVs showed higher levels of PTSD symptoms than IAVs, even five years after the war. This finding is consistent with previous studies showing that direct exposure to war is associated with higher rates of several psychopathologies, such as major depression (MDD), bipolar disorder, panic disorder, social phobia, obsessive-compulsive disorder (OCD), and PTSD (Orsillo et al., 1996). Furthermore, compared to veterans who do not suffer from PTSD, veterans who do, might show higher levels of anger and hostility (Jakupcak et al., 2007), higher levels of alcohol dependence, and are more at risk for medical conditions such as osteoarthritis, diabetes, heart disease, obesity, and elevated lipid levels (David et al., 2004). Our findings suggest that even compared to peers who were on active military service in a combat unit at the same time, DAV are at a higher risk for developing several aversive psychological effects as they reported higher PTSD symptoms, which indicates that they suffer from higher levels of stress. Higher stress in DAV is especially important given that these veterans do not have a formal diagnosis of PTSD. Veterans that are formally diagnosed with PTSD have a broad range of support – therapy, pension, social support, etc. However, cognitive, and emotional difficulties of veterans that were not formally diagnosed might easily be overlooked. A lack of diagnosis is likely to lead to lack of acknowledgment and treatment despite these evidently higher symptoms. Furthermore, the time since the war and the fact that the symptoms might not be directly related to the war (i.e. few, if any, war flashbacks), makes them even easier to miss.

A few limitations of the current study need to be considered. First, although the sample size was adequate to test the current study’s hypotheses, it is still relatively small, and the study needs to be replicated in a larger sample. Second, while the natural experiment design suggests that the active participation in the war is cause for the differences between the groups, the cross-sectional design precludes complete certainty. Third, unfortunately, in the current study we could not measure PTSD and STS symptoms in Palestinian families from Gaza nor were we able to recruit same-sex families. Understanding the unique pattern of post-war PTSD and familial STS in those population awaits future studies. Furthermore, to improve our understanding on how war-related trauma transfers to veterans’ parents, future investigations need to (a) focus on the nature of the relationship between the traumatised children and their parents, and the effect of different factors of this relationship on parents’ STS symptoms; (b) generalise the results that were obtained within the very specific circumstances of this conflict to other war veterans; and (c) investigate the psychological effects of war on the well-being of veterans who develop PTSD.

To conclude, in the current investigation we tested war veterans who directly participated in the 2014 Israel-Gaza war and veterans who were on active combat military duty at the same time but did not actively participate in the war. This controlled sample allowed us to focus on PTSD and STS symptom severity in war veterans and their parents. Our results suggest that (a) even five years after the war, PTSD symptoms in veterans who participated in the war were nearly twice as high as those of their peers who did not actively participate in the war; and (b) parents of DAV reported higher STS symptoms compared to parents of IAV, even years after the war. In general, mothers had higher STS symptoms compared to fathers, however, DAV PTSD symptoms were found to be correlated with their fathers’ STS symptoms, indicating that fathers STS symptoms might be a result of their son’s PTSD symptoms. These novel evidence for the transmission of stress indicate that war veterans’ parents are more prone to experience prolonged symptoms of stress and anxiety. Our results suggest that more consideration should be given to the long-term effects of war on the mental health of both veterans and their parents. Furthermore, mental health services should target war veterans and their parents and consider them an at-risk group for developing STS and other psychopathologies, even in the absence of a formal PTSD diagnosis.

Acknowledgements

We thank Prof. Yuval Neria of Columbia University Medical Center and the New York State Psychiatric Institute for his helpful comments and suggestions and Ms. Hadar Naftalovich for her input on this article.

Disclosure statement

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

Data availability statement

The data that support the findings of this study are openly available in Leshem et al. (2023).

Additional information

Funding

SL was supported by the Israel Science Foundation [grant number 1341/18]. Funding for this study came for internal institutional funds. These sources were not involved in this study at any stage or in any aspect.

Notes

1 PTSD was not assessed as part of the current study hence we cannot rule out that some participants might meet DSM-5 criteria for PTSD. However, none of the participants sought or received diagnosis for PTSD in the past.