Suicide and Life-Threatening Behavior © 2014 The American Association of Suicidology DOI: 10.1111/sltb.12140
1
The Specificity of the InterpersonalPsychological Theory of Suicidal Behavior for Identifying Suicidal Ideation in an Online Sample PHILIP J. BATTERHAM, PHD, ALISON L. CALEAR, PHD, PH D
AND
BREGJE A. J.
VAN
SPIJKER,
The interpersonal-psychological theory of suicidal behavior suggests that the combination of perceived burdensomeness and thwarted belongingness predicts suicidal ideation. However, the specificity of this prediction to suicidal ideation has not been tested. This study examined whether these constructs were consistently associated with different characteristics of suicidal ideation, and whether they were associated with mental health problems more broadly, in an online sample of 1,352 Australian adults. Findings indicated that the interaction between perceived burdensomeness and thwarted belongingness was associated only with suicidal ideation and consistent across multiple characteristics of ideation. The study broadly supported the specificity of the IPTS.
The interpersonal-psychological theory of suicidal behavior (IPTS) was developed by Joiner (2005) to identify the specific proximal PHILIP J. BATTERHAM, ALISON L. CALEAR and BREGJE A. J. VAN SPIJKER, National Institute for Mental Health Research, The Australian National University, Canberra, ACT, Australia. The authors gratefully acknowledge the College of Medicine, Biology and Environment, the Australian National University, which funded this study through an early career fellowship support grant. PB is supported by National Health and Medical Research Council (NHMRC, Australia) Early Career Fellowship 1035262. AC is supported by NHMRC Early Career Fellowship 1013199. This research is also supported by the NHMRC Centre of Research Excellence (CRE) in Suicide Prevention 1042580, and PB and AC are Chief Investigators on this CRE. The authors declare no competing interests. Address correspondence to Philip Batterham, Centre for Mental Health Research, Building 63, Eggleston Road, The Australian National University, Canberra ACT 0200, Australia; E-mail: [email protected]
antecedents of suicidal desire and death by suicide. The theory posits that suicidal desire develops in the presence of two distinct but separate interpersonal constructs, thwarted belongingness (isolation from others) and perceived burdensomeness (feeling as if one is a burden on others) (Van Orden et al., 2010). Thwarted belongingness is viewed as a fundamental unmet psychological need for social connectedness, while perceived burdensomeness arises out of interpersonal conflict, physical or mental illness, and other social constraints such as unemployment, and is characterized by a sense of liability and self-hatred (Van Orden et al., 2010). This desire for suicide, in combination with acquired capability for suicidal behavior, strongly predicts serious suicide attempt or death by suicide (Ribeiro & Joiner, 2009). Acquired capability for suicidal behavior is operationalized as habituation to painful stimuli through repeated exposure, together with reduced fear of death (Ribeiro & Joiner,
2 2009). Acquired capability may be developed through aversive experiences, such as childhood maltreatment, self-harm, previous suicide attempts, and exposure to violence, abuse, or trauma (Christensen, Batterham, Mackinnon, Donker, & Soubelet, 2014; Van Orden et al., 2010). The theory has been tested in a number of settings, including undergraduate students (Ribeiro & Joiner, 2009; Van Orden, Witte, Gordon, Bender, & Joiner, 2008), population-based cohorts (Christensen, Batterham, Soubelet, & Mackinnon, 2013), and in the military (Bryan, Morrow, Anestis, & Joiner, 2009). While research has generally shown support for the theory, there has been little research on whether thwarted belongingness and perceived burdensomeness are specific indicators for suicidal ideation or whether these constructs are more generally associated with poor mental health outcomes. Although thwarted belongingness and perceived burdensomeness have been shown to predict suicidal ideation above and beyond the contribution of depression (Joiner et al., 2009; Van Orden et al., 2008), the direct effects of these constructs with depression and anxiety have not been examined. Davidson, Wingate, Grant, Judah, and Mills (2011) reported that depression symptoms and social anxiety symptoms may increase suicidal ideation through their association with thwarted belongingness and perceived burdensomeness. Similarly, Jahn, Cukrowicz, Linton, and Prabhu (2011) demonstrated that the effect of depressive symptoms on suicidal ideation is mediated by perceived burdensomeness, and Christensen et al. (2014) reported that depression and anxiety are significantly associated with perceived burdensomeness but not thwarted belongingness. However, previous research has not investigated whether the risk factors included in the IPTS are also predictive of depression and anxiety. Given that the aim of the IPTS is to reliably and precisely identify proximal suicide risk, there is a need for research into the specificity of the theory. Examining the associations of
SPECIFICITY
OF THE
IPTS
the theorized constructs with symptoms of depression and anxiety may inform how well these constructs are able to differentiate suicide risk from risk of more common mental health problems. A related limitation of previous research testing the IPTS is the reliance on measures that assess a single dimension of suicidality (e.g., Bryan et al., 2009; Christensen et al., 2013; Joiner et al., 2009; Van Orden et al., 2010). There has been little examination of whether thwarted belongingness and perceived burdensomeness are general risk factors for all forms of suicidal ideation or whether they are specific to certain characteristics of suicidal ideation such as frequency of suicidal thoughts, controllability of suicidal thoughts, level of distress associated with ideation, or other aspects of suicidal ideation. Using a community-based online cohort of Australian adults, the goal of the present study was to assess the specificity of the IPTS in its association with suicidal ideation. Validation of the IPTS has only been conducted in one community-based life span sample (Christensen et al., 2013) and never in the online setting. Although people experiencing suicidal ideation tend to avoid seeking professional help as symptoms increase (Deane, Wilson, & Ciarrochi, 2001), they may instead seek help online (Gould, Munfakh, Lubell, Kleinman, & Parker, 2002). Therefore, the Internet may be an important setting to capture individuals at elevated risk of suicide, providing a unique opportunity for delivery of prevention programs that may effectively reduce suicide risk (van Spijker, van Straten, & Kerkhof, 2014). Multiple hypotheses were tested to examine the specificity of the IPTS in this study. First 2014, the association between the IPTS constructs and depressive symptoms, anxiety symptoms, and suicidal ideation was assessed. Based on the prediction of the IPTS, it was hypothesized that thwarted belongingness and perceived burdensomeness, and their interaction, would be significantly associated with suicidal ide-
BATTERHAM
ET AL.
ation (H1). In addition, it was hypothesized that thwarted belongingness and perceived burdensomeness would each be associated with depression and anxiety, as they are strong risk factors for suicide (e.g., Nock et al., 2009) (H2). However, it was hypothesized that the amount of variance explained by thwarted belongingness and perceived burdensomeness would be greatest for suicidal ideation (H3). Moreover, the interaction between thwarted belongingness and perceived burdensomeness was predicted to only be significantly associated with suicidal ideation, not depression or anxiety, as the IPTS posits that the combination of these constructs leads to suicidal desire (H4). In addition, the interaction between thwarted belongingness and perceived burdensomeness was hypothesized to be significantly associated with all aspects of suicidal ideation (frequency, controllability, closeness to attempt, distress, and interference) (H5). A secondary aim of the study was to test whether the predictions of the IPTS were supported for suicide attempt, as this aspect of the theory has not been examined in an online community sample (H6). Specifically, we tested whether the three-way interaction between thwarted belongingness, perceived burdensomeness, and acquired capability for suicide was significantly associated with presence of a suicide attempt in the past year.
METHOD
Participants and Procedure An online survey was developed to examine a range of mental health outcomes, with a particular focus on suicidal ideation. The survey was hosted on an Australian national university Web site and took approximately 30 minutes to complete; it covered psychological distress, depression, anxiety disorders, alcohol use, sleep problems, suicidal ideation, suicide literacy, suicide stigma, exposure to suicide, interpersonal risk factors for suicide, and a range of demographics (Batterham, Calear, & Chris-
3 tensen, 2013). To reach a diverse segment of the community, participants were recruited to complete the survey through online advertising on the social network site Facebook (Batterham, 2014). Recruitment advertisements were targeted to individuals aged 18 years and older living in Australia, and links noted that the survey had a mental health focus. From 12,773 clicks on advertisements that directed individuals to the online survey, 1,283 participants fully completed a survey and 610 partially completed a survey (of whom 448 provided no data). Included in the present analyses were 1,352 participants (93.6% of the 1,445 participants who provided any data) who completed all measures included in the present analyses. The remaining 93 participants were excluded using listwise deletion, as very few had data for the variables of interest. All participants were provided with written information about the study aims prior to commencing the survey and informed consent was given online. A brief list of state-based mental health service contacts was provided to individuals at the consent stage to assist those participants who might be seeking further help. Participants who completed the survey were provided with an additional list of mental health resources, including physician directory information, help lines, crisis care services, informational resources, and online services. No incentive was provided, and diagnostic analyses revealed no systematic outliers. The study received ethics approval from the Science and Medical Delegated Ethics Review Committee at the Australian National University (protocol number 2012/310). Measures Interpersonal Needs Questionnaire (INQ). The short form of the INQ (Van Orden et al., 2008) was administered to assess levels of thwarted belongingness (five items) and perceived burdensomeness (seven items), with each item rated on a 7-point scale. As the short form of the INQ has not previously been validated in a community
4 sample, the factor structure of the scale was assessed. Exploratory factor analysis of the items using principal axis factoring supported a two-factor solution corresponding to the two constructs, with these two factors accounting for 44% of total variance. Four of the items designed to assess thwarted belongingness loaded on one factor and six of the perceived burdensomeness items loaded on the other, each with factor loadings >0.7 on a single factor and
1
The Specificity of the InterpersonalPsychological Theory of Suicidal Behavior for Identifying Suicidal Ideation in an Online Sample PHILIP J. BATTERHAM, PHD, ALISON L. CALEAR, PHD, PH D
AND
BREGJE A. J.
VAN
SPIJKER,
The interpersonal-psychological theory of suicidal behavior suggests that the combination of perceived burdensomeness and thwarted belongingness predicts suicidal ideation. However, the specificity of this prediction to suicidal ideation has not been tested. This study examined whether these constructs were consistently associated with different characteristics of suicidal ideation, and whether they were associated with mental health problems more broadly, in an online sample of 1,352 Australian adults. Findings indicated that the interaction between perceived burdensomeness and thwarted belongingness was associated only with suicidal ideation and consistent across multiple characteristics of ideation. The study broadly supported the specificity of the IPTS.
The interpersonal-psychological theory of suicidal behavior (IPTS) was developed by Joiner (2005) to identify the specific proximal PHILIP J. BATTERHAM, ALISON L. CALEAR and BREGJE A. J. VAN SPIJKER, National Institute for Mental Health Research, The Australian National University, Canberra, ACT, Australia. The authors gratefully acknowledge the College of Medicine, Biology and Environment, the Australian National University, which funded this study through an early career fellowship support grant. PB is supported by National Health and Medical Research Council (NHMRC, Australia) Early Career Fellowship 1035262. AC is supported by NHMRC Early Career Fellowship 1013199. This research is also supported by the NHMRC Centre of Research Excellence (CRE) in Suicide Prevention 1042580, and PB and AC are Chief Investigators on this CRE. The authors declare no competing interests. Address correspondence to Philip Batterham, Centre for Mental Health Research, Building 63, Eggleston Road, The Australian National University, Canberra ACT 0200, Australia; E-mail: [email protected]
antecedents of suicidal desire and death by suicide. The theory posits that suicidal desire develops in the presence of two distinct but separate interpersonal constructs, thwarted belongingness (isolation from others) and perceived burdensomeness (feeling as if one is a burden on others) (Van Orden et al., 2010). Thwarted belongingness is viewed as a fundamental unmet psychological need for social connectedness, while perceived burdensomeness arises out of interpersonal conflict, physical or mental illness, and other social constraints such as unemployment, and is characterized by a sense of liability and self-hatred (Van Orden et al., 2010). This desire for suicide, in combination with acquired capability for suicidal behavior, strongly predicts serious suicide attempt or death by suicide (Ribeiro & Joiner, 2009). Acquired capability for suicidal behavior is operationalized as habituation to painful stimuli through repeated exposure, together with reduced fear of death (Ribeiro & Joiner,
2 2009). Acquired capability may be developed through aversive experiences, such as childhood maltreatment, self-harm, previous suicide attempts, and exposure to violence, abuse, or trauma (Christensen, Batterham, Mackinnon, Donker, & Soubelet, 2014; Van Orden et al., 2010). The theory has been tested in a number of settings, including undergraduate students (Ribeiro & Joiner, 2009; Van Orden, Witte, Gordon, Bender, & Joiner, 2008), population-based cohorts (Christensen, Batterham, Soubelet, & Mackinnon, 2013), and in the military (Bryan, Morrow, Anestis, & Joiner, 2009). While research has generally shown support for the theory, there has been little research on whether thwarted belongingness and perceived burdensomeness are specific indicators for suicidal ideation or whether these constructs are more generally associated with poor mental health outcomes. Although thwarted belongingness and perceived burdensomeness have been shown to predict suicidal ideation above and beyond the contribution of depression (Joiner et al., 2009; Van Orden et al., 2008), the direct effects of these constructs with depression and anxiety have not been examined. Davidson, Wingate, Grant, Judah, and Mills (2011) reported that depression symptoms and social anxiety symptoms may increase suicidal ideation through their association with thwarted belongingness and perceived burdensomeness. Similarly, Jahn, Cukrowicz, Linton, and Prabhu (2011) demonstrated that the effect of depressive symptoms on suicidal ideation is mediated by perceived burdensomeness, and Christensen et al. (2014) reported that depression and anxiety are significantly associated with perceived burdensomeness but not thwarted belongingness. However, previous research has not investigated whether the risk factors included in the IPTS are also predictive of depression and anxiety. Given that the aim of the IPTS is to reliably and precisely identify proximal suicide risk, there is a need for research into the specificity of the theory. Examining the associations of
SPECIFICITY
OF THE
IPTS
the theorized constructs with symptoms of depression and anxiety may inform how well these constructs are able to differentiate suicide risk from risk of more common mental health problems. A related limitation of previous research testing the IPTS is the reliance on measures that assess a single dimension of suicidality (e.g., Bryan et al., 2009; Christensen et al., 2013; Joiner et al., 2009; Van Orden et al., 2010). There has been little examination of whether thwarted belongingness and perceived burdensomeness are general risk factors for all forms of suicidal ideation or whether they are specific to certain characteristics of suicidal ideation such as frequency of suicidal thoughts, controllability of suicidal thoughts, level of distress associated with ideation, or other aspects of suicidal ideation. Using a community-based online cohort of Australian adults, the goal of the present study was to assess the specificity of the IPTS in its association with suicidal ideation. Validation of the IPTS has only been conducted in one community-based life span sample (Christensen et al., 2013) and never in the online setting. Although people experiencing suicidal ideation tend to avoid seeking professional help as symptoms increase (Deane, Wilson, & Ciarrochi, 2001), they may instead seek help online (Gould, Munfakh, Lubell, Kleinman, & Parker, 2002). Therefore, the Internet may be an important setting to capture individuals at elevated risk of suicide, providing a unique opportunity for delivery of prevention programs that may effectively reduce suicide risk (van Spijker, van Straten, & Kerkhof, 2014). Multiple hypotheses were tested to examine the specificity of the IPTS in this study. First 2014, the association between the IPTS constructs and depressive symptoms, anxiety symptoms, and suicidal ideation was assessed. Based on the prediction of the IPTS, it was hypothesized that thwarted belongingness and perceived burdensomeness, and their interaction, would be significantly associated with suicidal ide-
BATTERHAM
ET AL.
ation (H1). In addition, it was hypothesized that thwarted belongingness and perceived burdensomeness would each be associated with depression and anxiety, as they are strong risk factors for suicide (e.g., Nock et al., 2009) (H2). However, it was hypothesized that the amount of variance explained by thwarted belongingness and perceived burdensomeness would be greatest for suicidal ideation (H3). Moreover, the interaction between thwarted belongingness and perceived burdensomeness was predicted to only be significantly associated with suicidal ideation, not depression or anxiety, as the IPTS posits that the combination of these constructs leads to suicidal desire (H4). In addition, the interaction between thwarted belongingness and perceived burdensomeness was hypothesized to be significantly associated with all aspects of suicidal ideation (frequency, controllability, closeness to attempt, distress, and interference) (H5). A secondary aim of the study was to test whether the predictions of the IPTS were supported for suicide attempt, as this aspect of the theory has not been examined in an online community sample (H6). Specifically, we tested whether the three-way interaction between thwarted belongingness, perceived burdensomeness, and acquired capability for suicide was significantly associated with presence of a suicide attempt in the past year.
METHOD
Participants and Procedure An online survey was developed to examine a range of mental health outcomes, with a particular focus on suicidal ideation. The survey was hosted on an Australian national university Web site and took approximately 30 minutes to complete; it covered psychological distress, depression, anxiety disorders, alcohol use, sleep problems, suicidal ideation, suicide literacy, suicide stigma, exposure to suicide, interpersonal risk factors for suicide, and a range of demographics (Batterham, Calear, & Chris-
3 tensen, 2013). To reach a diverse segment of the community, participants were recruited to complete the survey through online advertising on the social network site Facebook (Batterham, 2014). Recruitment advertisements were targeted to individuals aged 18 years and older living in Australia, and links noted that the survey had a mental health focus. From 12,773 clicks on advertisements that directed individuals to the online survey, 1,283 participants fully completed a survey and 610 partially completed a survey (of whom 448 provided no data). Included in the present analyses were 1,352 participants (93.6% of the 1,445 participants who provided any data) who completed all measures included in the present analyses. The remaining 93 participants were excluded using listwise deletion, as very few had data for the variables of interest. All participants were provided with written information about the study aims prior to commencing the survey and informed consent was given online. A brief list of state-based mental health service contacts was provided to individuals at the consent stage to assist those participants who might be seeking further help. Participants who completed the survey were provided with an additional list of mental health resources, including physician directory information, help lines, crisis care services, informational resources, and online services. No incentive was provided, and diagnostic analyses revealed no systematic outliers. The study received ethics approval from the Science and Medical Delegated Ethics Review Committee at the Australian National University (protocol number 2012/310). Measures Interpersonal Needs Questionnaire (INQ). The short form of the INQ (Van Orden et al., 2008) was administered to assess levels of thwarted belongingness (five items) and perceived burdensomeness (seven items), with each item rated on a 7-point scale. As the short form of the INQ has not previously been validated in a community
4 sample, the factor structure of the scale was assessed. Exploratory factor analysis of the items using principal axis factoring supported a two-factor solution corresponding to the two constructs, with these two factors accounting for 44% of total variance. Four of the items designed to assess thwarted belongingness loaded on one factor and six of the perceived burdensomeness items loaded on the other, each with factor loadings >0.7 on a single factor and
