Exposure to Suicidal Behavior Predicts a Suicide Attempt, Depending on Past Psychiatric Diagnosis

Exposure to a suicide attempt and/or suicide death is associated with higher risk for an adolescent’s own suicide attempt. Previous studies have examined whether exposure affects adolescents’ own suicide attempts differently based on the presence of depressive symptoms or diagnoses, but these findings are inconsistent. We hypothesized that exposure to a suicide attempt would interact with history of a psychiatric diagnosis to predict a future suicide attempt among adolescents. Adolescents, aged 12-21, were recruited from seven high schools in the New York City metropolitan area. At baseline, they completed a two-stage suicide screen to assess for history of suicide attempt and suicide ideation, as well as the mood, anxiety, and substance use diagnostic modules (based on the previous 6 months) of the Computerized Diagnostic Interview Schedule for Children and were followed-up four to six years later to assess for lifetime exposure to a suicide attempt and suicide death (by someone they know) and any suicide attempts made since baseline. Race/ethnicity (Black vs. White), having at least one psychiatric diagnosis, suicidal ideation in the previous 3 months, and lifetime history of a suicide attempt were associated with a future suicide attempt, adjusting for gender. While exposure to a suicide attempt and/or suicide death did not predict a future suicide attempt, there was a significant interaction between having a psychiatric diagnosis at baseline and exposure to a suicide attempt and/or suicide death. Exposure to suicidal behavior may increase risk of future suicide attempts, but only among adolescents with at least one previous psychiatric diagnosis. Thus, compared to other adolescents, psychologically vulnerable adolescents may require more monitoring and support after exposure to suicidal behavior to reduce their heightened risk of attempting suicide. EXPOSURE TO SUICIDAL BEHAVIOR 3 Exposure to Suicidal Behavior Predicts a Suicide Attempt, Depending on Past Psychiatric Diagnosis Adolescents and young adults are at a particularly high risk of thinking about and attempting suicide. Suicide was the second-leading cause of death among Americans aged 15-24 in 2017 (Drapeau & McIntosh, 2018). Compared to all Americans aged 18 and over, adults aged 18-25 had the greatest prevalence of suicide ideation in 2017 (4.3 vs. 10.5%) (SAMHSA, 2017), and the proportion of Americans aged 18-25 attempting suicide was more than three times greater than the general adult population (SAMHSA, 2017). The majority of adults with lifetime suicide ideation or attempts report that they first thought about or attempted in their late teens or early twenties (Kessler, Borges, & Walters, 1999; Nock et al., 2008). Given the elevated rate of adolescent and young adult suicide ideation and attempts in comparison to other age groups, research has focused on the role of exposure to suicidal behaviors in risk of suicide attempts among adolescents and emerging adults. In 1787, Johann Wolfgang von Goethe published a novel that concluded with the main character, Werther, dying by suicide. Anecdotally, it was said that the novel influenced many young men in Europe to kill themselves using the same method after reading the book, although a formal analysis was never conducted. The pattern of copycat suicides was referred to as the “Werther effect” (Phillips, 1974). Centuries after the initial publication of Goethe’s novel, the extent to which exposure to suicide affects suicide risk is still a lingering question, whether the exposure be through the media or through personal relationships. Recently, mental health professionals have expressed concern that the television series, 13 Reasons Why, encourages young viewers to imitate the suicide of the main character (Ferguson, 2018). A study on EXPOSURE TO SUICIDAL BEHAVIOR 4 exposure to media reports of suicide found that the greatest increase in suicide deaths in the four months following the news reporting of a suicide occurred among people ages 15-25, suggesting that youth are at a heightened risk of engaging in suicidal behavior following media reports of suicide (Romer, Jamieson, & Jamieson, 2006). Additionally, a longitudinal study found an increased incidence of suicide deaths in secondary schools after a student’s suicide death, suggesting that adolescents may imitate the suicidal behaviors of their classmates (Poijula, Wahlberg, & Dyrerov, 2001). Thus, evidence suggests that exposure to suicide attempts and suicide deaths through the media and by knowing someone personally may pose a particularly strong risk among high school-aged adolescents. Consequently, studies have focused on the effect of exposure to a suicide attempt or suicide death on risk of suicidal behavior among adolescents. Although the effect of suicide exposure on adolescents has no universally accepted underlying mechanism, multiple theories have been proposed. Researchers have suggested that exposure to suicide encourages “imitation” of suicidal behavior through social learning, in that adolescents learn the methods to attempt suicide from family-members and friends (De Leo & Heller, 2008). In order to conclude that imitation is the mechanism responsible for an adolescent’s suicide attempt following an exposure to a suicide attempt or death, exposure must have occurred prior to the attempt. Another theory is that adolescents who engage in or are vulnerable to suicidal behavior are more likely to form friendships with other suicidal adolescents (Joiner, 2003). Thus, adolescents are prone to making “assortative friendships” but do not necessarily transmit their suicidal behavior. These theories represent two possible pathways through which the suicidal behavior of one individual may influence subsequent suicidal behavior in others, although it is unclear which theory has more empirical support. EXPOSURE TO SUICIDAL BEHAVIOR 5 While the evidence is mixed, the vast majority of findings suggest an association between exposure to suicide attempts and/or suicide deaths and adolescents’ own suicide attempts. Previous studies on exposure to suicidal behavior have focused on whether knowing at least one person who attempted suicide, died by suicide, or both increased adolescents’ risk of making a suicide attempt. A longitudinal study of a nationally representative sample of US adolescents (Feigelman & Gorman, 2008) and a Swedish case-control study of adolescents (MittendorferRutz, Rasmussen, & Wasserman, 2008) found that exposure to a suicide death predicted a future suicide attempt. A longitudinal study of Canadian adolescents found that exposure to a suicide death predicted both future suicide ideation and a suicide attempt (Swanson & Colman, 2013). Similarly, exposure to a suicide attempt has been found to predict future suicide attempts in nationally representative longitudinal studies of US adolescents and young adults (MittendorferRutz et al., 2008; Nanayakkara, Misch, Chang, & Henry, 2013; Randall, Nickel, & Colman, 2015). Cross-sectional studies have reported similar findings. One cross-sectional study of a community sample in Hong Kong found that adolescents who knew someone who made a suicide attempt were more likely to report having made a suicide attempt, themselves (Wong, Stewart, Ho, Rao, & Lam, 2005). Still, a cross-sectional school study of American Indians and Alaska Natives that examined exposure to a suicide attempt or a suicide death (without examining them separately) found that any exposure was associated with a suicide attempt among adolescents and young adults (Borowsky, Resnick, Ireland, & Blum, 1999). Additionally, a cross-sectional family study in the United States and a cross-sectional study of New Zealand high school students have also found associations between any exposure and suicide attempt among adolescents (Burke et al., 2010; Chan, Denny, Fleming, Fortune, PeirisEXPOSURE TO SUICIDAL BEHAVIOR 6 John, & Dyson, 2017). Thus, many studies have found an association between exposure to a suicide attempt and/or death and suicide attempts among adolescents. Other longitudinal research has contradicted these findings. A 3-year longitudinal study of friends of adolescent suicide victims and unexposed community controls found no relationship between exposure to a suicide death and the incidence of suicide attempts during the follow-up period (Brent, Moritz, Bridge, Perper, & Canobbio, 1996). A population-based case-control study of patients in the emergency department following a suicide attempt and control individuals found that exposure to suicide attempts and/or deaths was cross-sectionally associated with decreased suicide attempts among adolescents and young adults (Mercy et al., 2001). While a few of these findings have not found an association between exposure to suicidal behavior and suicide attempts in adolescents, the overwhelming majority of these studies have found significant associations, indicating the importance of studying the negative effects of exposure to suicidal attempts and deaths. In examining the potential impact of family suicidal behavior, some studies have found significant associations between family suicide deaths and/or suicide attempts and adolescent suicide attempts (Brent et al., 2015; Cerel & Roberts, 2005; Mittendorfer-Rutz et al., 2008), whereas others have found associations between friend/acquaintance suicides and/or suicide attempts with adolescent attempts (Cerel, Roberts, & Nilsen, 2005; Feigelman & Gorman, 2008; Randall, Nickel, & Colman, 2015; Swanson, & Colman, 2013). Other research has compared the impact of exposure to familial suicidal behavior, versus that of a friend or acquaintance, on adolescent suicide attempts. One nationally representative cross-sectional study found that exposure to familial suicide attempts, but not peer suicide attempts, was associated with suicide attempts among adolescents (Ali, Dwyer, & Rizzo, 2011). In contrast, a cross-sectional study o