Anestis et al. 375 xelude the nossibility that ar nitial o rt for the construct validity of the individual extensively considered and planned an attempt long before engaging in the behavior but did not think about directly consider the IPTS model.In a series of studies com Fo ng the pain tole of individu hospita detail during an m an cidental ini from that episode with or without attempting,and then and colleagues (1996)and Orbach.Mikulincer.King.Cohen. attempts suicide in the early portion of a later episode in a and Stein (1997)reported that attempters exhibited higher r entirely c with the earlier plar n tol vell th and thatn out nlan?second hy framing the ansy exhibited greater pain tolerance than did individuals with the four response options involve less than 24 hr,the mea- zero or one prior attempt.Such findings are consistent with sure may push respondents to think about premeditation as the notio that intentionally inflic ing harm onon ppens onl ing the r that the po uals can gradually overcome the fear of discomfort and death asing and decr reasing (or even ceasing entirely)across thro ough deliberate practice)and that a longer history of self different periods but still bustly related to increas shorter time frame with this item,with answers restricted to Prinstein (2005)reported that increased frequ 0("none").1 ("less thar 3 hr"),and 2 ("more than 3 hr") sociated v with pain analgesia during NSSI episodes urth priming up to an atte mpt ( ronic possibility.as non-impulsive greater likelihood of having made a suicide atte attempts would thus still be considered events that were dence for the importance of ain tolerance in the cap pacity for bome of minimal forethought) suicidal behavio one c f these studies Proposed Alternative model of the ences.leaving Relationship Between Impulsivity and open thep pain tole ance acilitat severe self-harming Suicidal Behavior h.the Trait Imbulsivity Efforts tor In contrast to models that conceptualize suicidal behavior as Suicide Scale (ACSS:Be der,Gordon,Bres ner,2011).Using this as( rect (Figure la hav rep mer nel rer s of the ire capability than &。 th by idal b ior,an individual must acquire the capability for suicid ability.men engage in significantly fewer non-lethal sui defined as habituation both to physiological pain and to th attempts fo every lethal attempt than do women,and exposure to pain ary pers suicidal behavior.In this sen the ity te sidering that do not in inflicted gunshot wounds (Anestis&Bryan,2013).Such idly but rather reflects a serie of en with expe findings indicate that certain indiy potentially due to pair s (e. gg of the initial fear e eA R Smith e ward greater pain tolerance and diminished fear.are more evidence that heritability of the acquired capa- able to e engage in lethal suicidal behavior than are others. bility is approximately 65%). who might need to repeatedly engage in low lethality meansAnestis et al. 375 the response scale appears to exclude the possibility that an individual extensively considered and planned an attempt long before engaging in the behavior but did not think about it extensively immediately preceding the attempt. For instance, if an individual plans a suicide attempt with great detail during an episode of elevated suicide risk, recovers from that episode with or without attempting, and then attempts suicide in the early portion of a later episode in a manner entirely consistent with the earlier plan, would this be impulsive or simply reflect the enaction of a well thought￾out plan? Second, by framing the answers such that three of the four response options involve less than 24 hr, the mea￾sure may push respondents to think about premeditation as something that happens only during the moments immedi￾ately preceding the behavior. This framework does not offer the possibility that premeditation follows an episodic course, increasing and decreasing (or even ceasing entirely) across different periods of time but still building on itself with each progressive episode of contemplation. Importantly, some studies (e.g., O’Donnell et al., 1996) have provided an even shorter time frame with this item, with answers restricted to 0 (“none”), 1 (“less than 3 hr”), and 2 (“more than 3 hr”), further priming individuals to conceptualize planning as something that occurs only in the moments directly leading up to an attempt (another ironic possibility, as non-impulsive attempts would thus still be considered events that were borne of minimal forethought). Proposed Alternative Model of the Relationship Between Impulsivity and Suicidal Behavior Trait Impulsivity In contrast to models that conceptualize suicidal behavior as frequently impulsive and that view the relationship between trait impulsivity and suicidal behavior as direct (Figure 1a), we propose that trait impulsivity is best regarded as one of many distal risk factors for suicidal behavior (see Figure 1b). This proposition is presented through the lens of the interpersonal-psychological theory of suicidal behavior (IPTS; Joiner, 2005). The IPTS proposes that, in addition to desiring death by suicide and/or non-lethal suicidal behav￾ior, an individual must acquire the capability for suicide— defined as habituation both to physiological pain and to the fear of death—through repeated exposure to painful and provocative events before he or she can engage in lethal or near-lethal suicidal behavior. In this sense, the capacity to engage in suicidal behavior does not typically develop rap￾idly but rather reflects a series of encounters with experi￾ences that alter an individual’s response to pain and impending death, with repeated exposures resulting in a dampening of the initial fear response (see A. R. Smith et al., 2012 for evidence that heritability of the acquired capa￾bility is approximately 65%). Initial support for the construct validity of the acquired capability for suicide was reported in studies that did not directly consider the IPTS model. In a series of studies com￾paring the pain tolerance of individuals who were hospital￾ized in response to a suicide attempt and individuals admitted to the same emergency room due to accidental injury, Orbach and colleagues (1996) and Orbach, Mikulincer, King, Cohen, and Stein (1997) reported that attempters exhibited higher pain tolerance than did individuals admitted due to acciden￾tal injury and that individuals with multiple suicide attempts exhibited greater pain tolerance than did individuals with zero or one prior attempt. Such findings are consistent with the notion that intentionally inflicting harm on oneself has a greater impact on pain tolerance than does accidental injury (thereby providing initial support for the notion that individ￾uals can gradually overcome the fear of discomfort and death through deliberate practice) and that a longer history of self￾inflicted injury is more robustly related to increased pain tol￾erance (providing initial support for the notion that this process unfolds through habituation). Similarly, Nock and Prinstein (2005) reported that increased frequency of NSSI is associated with pain analgesia during NSSI episodes (evi￾dence for habituation), and Nock et al. (2006) reported that pain analgesia during NSSI episodes is associated with a greater likelihood of having made a suicide attempt (evi￾dence for the importance of pain tolerance in the capacity for suicidal behavior). None of these studies utilized longitudi￾nal data demonstrating increases in pain tolerance following repeated engagement in painful and/or provocative experi￾ences, leaving open the possibility that elevated levels of pain tolerance facilitate severe self-harming behaviors entirely different from any habituation process. As such, the research base on this point is not definitive. Efforts to measure the acquired capability directly have centered on the Acquired Capability for Suicide Scale (ACSS; Bender, Gordon, Bresin, & Joiner, 2011). Using this measure, researchers have reported that men report higher mean levels of the acquired capability than do females and military personnel report higher mean levels of the acquired capability than do civilians (including civilians with multiple lifetime suicide attempts; Bryan, Morrow, Anestis, & Joiner, 2010; Van Orden, Witte, Gordon, Bender, & Joiner, 2008). Further supporting the construct validity of the acquired capability, men engage in significantly fewer non-lethal sui￾cide attempts for every lethal attempt than do women, and military personnel engage in significantly fewer non-lethal suicide attempts for every lethal attempt than do civilians, even when considering attempts that do not involve self￾inflicted gunshot wounds (Anestis & Bryan, 2013). Such findings indicate that certain individuals, potentially due to their life experiences (e.g., basic training, physical aggres￾sion, NSSI) in combination with a genetic predisposition toward greater pain tolerance and diminished fear, are more able to engage in lethal suicidal behavior than are others, who might need to repeatedly engage in low lethality means Downloaded from psr.sagepub.com at Remen University of China on September 6, 2015