This study was undertaken to further explore the familial transmission of risk for suicidal behavior by examining the relationship between reported childhood abuse in biological parents diagnosed with major depressive disorder and risk for suicidal behavior in their offspring. The main findings are that reported childhood sexual abuse, but not physical abuse, in parent probands is related to suicidality and other risk factors for suicide attempt both in the probands themselves and in their biological off-spring. More specifically, reported childhood sexual abuse in probands is correlated with greater likelihood of the proband having made at least 1 lifetime suicide attempt and having comorbid PTSD and dysthymic disorder; more severe lifetime impulsivity, hostility, and aggression; and earlier age at onset of major depressive disorder compared with parent probands with no sexual abuse history. Offspring of sexually abused probands were significantly more likely to have made at least 1 lifetime suicide attempt, to have been sexually abused themselves, to have a diagnosis of PTSD, and to have higher levels of impulsivity. They were not more likely to have a diagnosis of major depressive disorder or report depressive symptomatology, but those who did have major depressive disorder had a significantly earlier age at onset of their first depressive episode. Sexual abuse, however, was not directly transmitted from proband to offspring—perpetrators of offspring sexual abuse were more likely to be from outside the home. In path analysis, offspring sexual abuse and offspring impulsivity were both found to mediate the relationship between proband sexual abuse and offspring suicide attempt. The relationship between the environment (sexual abuse) and the trait (impulsivity) variable was additive, not interactive. Thus, the path from proband sexual abuse to offspring sexual abuse and offspring attempt was distinct from the path from proband sexual abuse and proband impulsivity to offspring impulsivity and offspring suicide attempt. This indicates that both environmental and trait variables are familially transmitted and increase the risk for offspring suicidal behavior. These results replicate and extend our previous findings
5 in a larger sample in which additional parameters of abuse were investigated.
In our study, there was a specific effect of sexual abuse, as compared to physical abuse, both on the offspring likelihood of making a lifetime suicide attempt and on the familial transmission of suicidal behavior to offspring. While some studies have found a relationship between physical abuse and suicidal behavior, the majority of studies show a much greater effect with a history of sexual rather than physical abuse,
26,27,50–52 and some report a greater risk for suicide attempts in those reporting more than 1 type of abuse.
53 When controlling for offspring age and gender, offspring of sexually abused probands had more severe lifetime impulsivity than did offspring of nonabused or physically abused probands. Only offspring of physically abused probands had more severe lifetime aggression, but they were not more likely to have made a suicide attempt, nor were they more impulsive. Thus, offspring impulsivity was associated with having a sexually abused parent, and offspring aggression was associated with having a physically abused parent. Aggression has been reported to be a familially transmitted trait associated with suicidal behavior,
12 and we have also previously reported a relationship between childhood abuse, impulsivity, and suicidal behavior in borderline personality disorder.
19 It is unclear, given the well-documented relationship between impulsive aggression and suicidal behavior, why impulsivity alone, and not aggression, was related to the transmission of suicidal behavior in this study. Perhaps covariables such as age, gender, and type of abuse mediate this association. Further research is necessary to investigate what may be a possible interaction between type of abuse, type of personality trait, and the familial transmission of traits associated with suicidal behavior. It is important to emphasize that in this study, offspring of sexually abused probands were more likely to be sexually abused themselves, but that the majority of reported perpetrators of sexual abuse were extrafamilial. Thus, the transmission of sexual abuse from proband to offspring was not direct. Indirect effects that may result in familial transmission may be traits that increase the chances of sexual abuse such as parental values, religious values, impulsive traits and discipline,
54,55 and offspring traits resulting in sexually suggestive behavior.
In contrast, physical abuse was associated with in-home perpetrators. One study
56 examined the possible differences in family environments related to both in-trafamilial and extrafamilial sexual abuse, but found considerable similarities in the family of origin environments of female adult survivors of sexual abuse, regardless of type of perpetrator, Little is known regarding differences in perpetrators in survivors of physical and sexual abuse. It is possible that in our current study, the sexually abused offspring were less forthcoming about the intrafamilial perpetrators of sexual abuse due to shame or fear of exposure.
Sexual abuse may be more specifically related to suicidal behavior because it is more closely associated with feelings of shame
57 or internal attributions of blame,
58–60 which may increase vulnerability to internalizing behaviors such as self-harm and suicidality, and to PTSD. For instance, female survivors of sexual abuse who reported abuse by an immediate family member before 10 years of age recalled making internal attributions of blame when they were children, which were predictive of a history of suicide attempts.
61 A longitudinal study
62 found that high levels of shame persisted among sexually abused youth 6 years after the time of discovery, which may contribute to maintenance of PTSD symptoms. Less is known regarding the attributions related to physical abuse.
63In addition, the familial dynamics surrounding sexual in contrast to physical abuse may contribute to risk for suicide. For instance, emotional and psychological abuse appear more closely related to sexual than to physical abuse.
64,65 Also, a history of childhood sexual and emotional abuse was highly correlated with intimate partner violence, PTSD, and suicide attempts among a community sample of women.
64 There is evidence that mothers who were sexually abused in childhood have higher rates of permissive parenting behaviors that may endanger their offspring in terms of sexual abuse,
54 have difficulty establishing clear generational boundaries, and use harsh physical discipline.
66Children of sexually abused mothers may be exposed to other forms of trauma, such as witnessing domestic violence. For example, in our study, the offspring of sexually abused probands were more likely to have PTSD that was not just related to having experienced abuse themselves. In reviewing the traumas that led to their PTSD diagnosis, a number of patterns emerged. The offspring who did report abuse were often victims of their father’s, or stepfather’s, physical or sexual abuse, so that the sexually abused proband mother was not the perpetrator, but often chose an abusive partner.
64 Offspring of sexually abused probands also reported other types of trauma, such as witnessing of violence toward family members both in the home and in their neighborhoods. PTSD in the offspring of sexually abused probands may have been related to their experiences being raised by traumatized sexually abused probands with severe comorbid psychopathology, particularly related to substance use. In addition, earlier onset of first major depressive episode in the offspring was correlated with sexual abuse in the proband. Another study
54 found that childhood sexual abuse in a mother was related to maternal depression and partner violence.
In this study, proband sexual abuse, and sexual abuse in the offspring, was related to suicide attempt status but not to risk factors for suicidality such as hopelessness or suicidal ideation. It is possible that impulsivity as a mediator between parental abuse and offspring suicidality represents a pathway for familial transmission of suicide risk that is distinct from that of hopelessness and suicidal ideation. Indeed, hopelessness and impulsivity were found to independently contribute to suicide risk in individuals with borderline personality disorder.
67Strengths of this study are that it is cross-generational, that it controls for depression in the proband, and that pro-bands and offspring were interviewed in person by independent interviewers as part of the prospective design. The results suggest that reported sexual abuse in the parent increases risk of suicide attempt in the child through transmission of abuse and impulsivity and that physical abuse in the parent increases aggression in the child. We relied on reported history of abuse, but evidence provided by the present study as well as others
68,69 suggests that abuse is underreported. In this study, there was high agreement between 2 retrospective interview methods in the report of both physical and sexual abuse, and discrepancies between the 2 methods were often due to underreporting.
The cross-sectional design of this study limited the ability to explore interactional variables that might shed light on mediation. Our results indicate the need for future longitudinal research regarding the effects of childhood abuse on the familial transmission of suicidal behavior. In prospective studies,
70 subsequent suicidal behavior has been found in the same individuals who were identified in childhood to have been sexually abused,
71 and children of mothers with major depressive disorder were more likely to report suicidal ideation.
Future longitudinal research should look more closely at the temporal relationship between appearance of major depressive disorder and PTSD relative to childhood abuse, as well as onset of suicidal behavior. Familial factors surrounding different types of childhood trauma and their relationship to the development of suicidal behaviors should be identified and investigated. The role of shame, feelings of betrayal, self-hate, attachment styles, and attributions related to various forms of abuse should be examined. Understanding how other factors known to mediate between childhood abuse and depression/suicidal behavior (such as attribution of blame and parenting styles) may aid in the identification of interventions to prevent morbidity and mortality.
TAKE-HOME POINTS
- A history of childhood sexual abuse is a risk factor for suicidal behavior in adulthood.
- Childhood sexual abuse in a patient is a risk factor for suicidal behavior in that patient’s offspring.
- Assessment for suicide risk should include taking a history of childhood abuse as well as family history of childhood abuse.