Historically, single types of childhood adversities were investigated when assessing their effect on developing lifetime mental disorders in adulthood. Some looked at the individual effects of childhood physical abuse, sexual abuse or neglect[1, 2]. Others investigated the differential effects of more than one adversity such as childhood maltreatment (abuse, neglect), parental substance use [3], or bullying [4].

More recently, research investigating this has expanded to include a larger variety of adversities using the World Mental Health (WMH) surveys including interpersonal loss (parental death, divorce, or separation), parental maladjustment (mental illness, substance misuse, criminality, and violence), as well as maltreatment (physical abuse, sexual abuse, and neglect), in addition to life-threatening respondent physical illness and family economic adversity [5]. It was found that the probable attributable risk of childhood adversities on first onset of adult disorders is 29.8% for all disorders across 21 countries, notably those related to maladaptive family functioning (including neglect, abuse, and family psychopathology) [5].

Studies exploring this wide range of childhood adversities and major collective large-scale trauma such as war on the first onset of mental disorders later in adulthood are lacking. More specifically, and in the case of the long-term impact of war exposure in childhood on the development of mental disorders, none to our knowledge, compared them to past non-war childhood other traumatic events [6, 7], let alone on the first onset of mental disorders in adulthood. Additionally, a lot of studies focused on very few or even one war event to predict mental disorders at a later stage in life. This is of major importance as evidenced by a report from our group including some of the co-authors showing that children and adolescents who were exposed to war were also more likely to be exposed to non-war childhood adversities [8]. One study investigated one traumatic war event focusing on the lasting impact of parental loss, specifically the death of a father during childhood or adolescence due to war-related violence, on the mental health and functioning of young adults. The findings indicate that individuals who experience this type of loss face a heightened risk of mental health issues and functional impairments during their young adulthood [9]. The few studies in the literature that we could find and which looked at both sets (war and non-war) were very short-term (one 4 years post-war in Northern Uganda [10] and one after one year in Kabul, Afghanistan [11]) and found both war and childhood adversities to be associated with negative consequences on mental health [10, 11]. Two additional studies from our group, where violence in the family emerged as a stronger predictor than war exposure in predicting the persistence of many mental health disorders, were also very short-term (one year) prospective studies. However, none of these studies addressed the issue of first onset in adulthood after war exposure [12, 13].

We had shown in a large national study The L.E.B.A.N.O.N study (Lebanese Evaluation of the Burden of Ailments and Needs of the Nation) [14] that exposure to war, in general, was associated with the first-ever onset of mood, anxiety, and externalizing disorders [15]. In this paper we try to fill a gap by investigating, in this same national study, the outcome of concomitant exposure, in childhood and adolescence to war and a wide range of non-war adverse traumatic events on first onset in adulthood (>18yrs) of mood and anxiety disorders.

The data used in this paper is from the L.E.B.A.N.O.N. study conducted by the Institute for Development Research Advocacy and Applied Care (IDRAAC) in association with the Department of Psychiatry and Clinical Psychology at the University of Balamand, Faculty of Medicine and St. George Hospital University Medical Center (SGHUMC), and is part of the World Health Organization (WHO) WMH Survey Initiative conducted in association with the Harvard Medical School in the US. This study was approved by the Institutional Review Board (IRB) committee of the SGHUMC Faculty of Medicine, University of Balamand, Lebanon, which is registered with the U.S. Office of Human Research Protections (OHRP) in the Department of Health and Human Services.

Negative life events in childhood have been repeatedly shown to be associated with mental disorders in adulthood [10, 16] and the challenge remains to cover all negative events. The mechanisms underlying the associations are not well understood and are thought by some to be essential primers interacting with the genetic makeup of individuals early on in life [17, 18]. All too commonly, one life event or a group of events has been singled out to study this robust association. The most commonly studied events are referred to as “childhood adversities”. Another category of negative events belongs to the general category of “traumatic events”. War brings an additional series of traumatic events that can further impact the growing brains of children and adolescents. We had previously found that war events were significantly associated not only with first onset of mental disorders but also with their severity [14, 15, 19]. In a previous analysis of the data from the same sample, we had explored the effect of cumulative war exposure on first onset of mental disorders and found that war was a significant predictor of mental health disorders, particularly of mood and anxiety which are the focus of the current analysis (respective ORs [95% CIs]: 3.32 [2.0-5.6], 5.92 [2.5-14.1]) [15].

Studying war and non-war-related traumatic events is obviously imperative since events from categories seem to co-occur more in specific settings (eg: families, and neighborhoods) [8]. To our knowledge, this is the first published national study assessing simultaneously the relation of childhood exposure to war as well as that of non-war adversities to the first onset of mental disorders mainly mood and anxiety. Also, previous research did not assess specific events with types of disorders [20]. In addition, the analysis in previous research did not examine specific patterns in males vs. females. In this study, we focused on the stratification by gender and the differences in the effect of war and non-war CTEs on the first onset of the disorders.

The results of this study should be interpreted in the light of some limitations. First, as data were collected through face-to-face interviews, social desirability bias may have resulted in the underreporting of adversities and traumas. Second, recall bias could also have led to the under-reporting of symptoms of mental disorders. The recall of war and non-war traumata may have been biased by reporting on events that occurred many years or decades prior to the interview. Also, there are no studies that compare the differential recall between war and non-war traumatic events. Thirdly, we could not study the temporality of exposures and onset of mental disorders below age 18 since we do not have data on the exact “onset” of childhood events before age 18 years. Fourthly, we have not measured psychotic disorders, nor impulse and substance use disorders. Fifthly, the sample size might have limited some of our findings. Sixthly, the sample did not include institutionalized respondents. Seventhly, not all specific war events are represented in this population of childhood exposure such as kidnapping which we had found to be linked to severe and protracted consequences and to be linked to the longest PTSD of all war traumata and if it is present, it might have had different effects [21]. Eight, childhood adversities were measured only till age 16y so there might have been other adversities between 16y and 18y and if we had measured them, they could have increased the importance of non-war relative to war. Nine, the death of parents due to war could not be put under war adversities and thus it is possible that this single exception might have shown a delayed effect on the first onset of disorders. Lastly, we did not measure for severity, frequency, and recurrence of the war and non-war variables, so we could not account for this as the non-war (happening inside the family) could be a chronic exposure while the war exposure could be a one-time event or of a less frequent nature.

Notwithstanding the above limitations, when all the childhood traumatic events were analyzed together in multivariable models, it is clear that the most universal predictor for adult onset of both mood and anxiety disorders were the non-war traumata, and within those, more specifically “neglect and abuse”. This is in line with Kessler et al, who have found that maladaptive family functioning is clearly the most important predictor, although not the only one; still its effect on first onset is much stronger early on in life than first onset later on [5].

War trauma, by contrast, predicted (significant at bivariate and borderline at the multivariable level) the first onset after age 18 years of mood disorders only in males. Although its effect lost practically its importance compared to non-war trauma, when we put them together in a multivariable model, it was still present.

Moreover, when we looked at the first onset of disorders before age 18 y, war exposure was related to mood and anxiety disorders in females, but only to anxiety in males. This is important because it implies that the effect of traumatic events might not be equal for all these events over time. It is probable that some events (such as the case of war in females) exerted their effects on first onset of mood disorders early on after exposure and thus did not have a delayed effect later in life. Whereas the more powerful non-war CTEs exerted their effect on both mood and anxiety for the first time ever before 18y, their effect continued to unravel at a later stage after 18y as shown elsewhere [5]. It is important to acknowledge here the possibility that re-exposure to war in adulthood (and other disasters) might unravel an increased risk that lay “dormant” such as the case of PTSD.

The reason why some traumata continue to uncover their effects long after the exposure while others do not is an important issue that this research was not designed to explain. Of course, there are many reasons affecting first onset of mood or anxiety disorders including genetics and other temperamental characteristics [22] but everything else (non-war CTEs) being equal, war exposure seems to exert its effect mostly on the first onset before age 18y in females and after 18y in males. Also, it is possible that one of the childhood adversities, parental psychopathology, has by definition long term effects that are not the result of “direct” trauma only but also in determining important lifelong genetic and behavioral liabilities.

These findings are interesting clinically at the individual and collective levels; thus, when waving the history of a society (in this case, Lebanon) or an individual the effect of war, especially its relative weight to other traumata, the potential effect of each takes on a different dimension on a personal or collective level. It would be interesting to see this work replicated in the setting of other major disasters including wars and confirm whether the hard-core non-war childhood adversities remain the most important predictors of ^the first onset of internalizing disorders in adulthood.

In summary, our study reveals that war-related childhood traumatic experiences (CTEs) were not significant predictors of mood disorder onset among the total sample and males. However, among females, general war exposure was a predictor for mood onset below 18. Notably, non-war CTEs, specifically neglect and abuse, remained significant predictors in the total sample in below 18 onsets and adult onset, emphasizing the enduring impact of these experiences on mental health outcomes. The variability in other predictors by gender between below 18 and adult-onset was discussed above. As for anxiety onset, our study reveals that different war-related CTEs predict the onset of anxiety disorders at different age intervals. Active war exposure predicts adult-onset, while general war exposure is linked to onset below 18, with no gender-specific effects. Among non-war CTEs, parental loss predicts adult anxiety in females, neglect and abuse predicts adult anxiety in males, while various factors contribute to onset below 18, including parent psychopathology for the total sample and both genders and trauma to others for the total sample and female.

Consequently, childhood traumata are not equal in predicting the first onset of mood and anxiety disorders neither in adulthood or below 18. Family malfunctioning of the non-war CTEs looks to carry the longest such risk and war more of shorter immediate effects. This might change though with re-exposure to war in adulthood which might unravel dormant vulnerability.