Prev Sci DOI 10.1007/s11121-013-0444-0
Effects of Rumination and Optimism on the Relationship Between Psychological Distress and Non-Suicidal Self-Injury Alicia K. Tanner & Penelope Hasking & Graham Martin
# Society for Prevention Research 2013
Abstract In recent years, increasing concern regarding nonsuicidal self-injury (NSSI) among adolescents has prompted investigation of factors that may prevent this behavior. This study examined the relationship between psychological distress and NSSI in a community sample of adolescents, and the moderating effect of both optimism and rumination on this association. Two thousand five hundred seventy-two participants (12–18 years) completed self-report questionnaires assessing psychological distress, cognitive, and emotional characteristics, and NSSI history. Ten percent of the sample reported a history of NSSI, and as hypothesized, optimism moderated the relationship between psychological distress and NSSI; the association was only evident when optimism was low. Rumination was not found to moderate the relationship between psychological distress and NSSI. These findings highlight the utility of considering optimism in NSSI prevention and early intervention programs. Keywords Self-injury . NSSI . Rumination . Optimism . Psychological distress Non-suicidal self-injury (NSSI), the purposeful destruction of one’s own body tissue without conscious suicidal intent (Nock and Favazza 2009), is a prevalent behavior and the single greatest risk factor for future self-injury and suicide (Skegg 2005). Current prevalence estimates range between 9 and 45 % (Lloyd-Richardson et al. 2007; Martin et al. 2010; Plener et al. 2009). Given that NSSI is as a prominent threat to A. K. Tanner : P. Hasking (*) School of Psychology and Psychiatry, Monash University, Clayton 3800, VIC, Australia e-mail: [email protected] G. Martin Center for Clinical Psychiatry and Neuroscience, The University of Queensland, Brisbane, Australia
physical health and psychological functioning in adolescence (Hawton and James 2005) and may precipitate suicidality (Nock et al. 2006), further research is needed to clarify individual vulnerabilities for NSSI and to identify psychological processes that may influence these associations. Although individuals with psychological impairment are at greater risk of NSSI (Martin et al. 2010; Williams and Hasking 2010), such outcomes are not inexorable, and examining factors that may confer resilience to NSSI is imperative for development of effective NSSI intervention and prevention strategies. In this paper, we explore the roles of rumination and optimism in the relationship between psychological distress and NSSI with a view to identifying psychological factors that may increase risk of, or protect against, NSSI. Self-injurers report higher levels of subjective distress in response to aversive or stressful experiences (Najmi et al. 2007; Skegg 2005), and higher prevalence of depressive and anxiety disorders (Klonsky et al. 2003). The high emotional reactivity and dysregulation that characterizes several psychiatric conditions has been proposed as a causal mechanism associating these disorders with NSSI (Klonsky and Muehlenkamp 2007); people may self-injure to cope with this elevated distress (Nock 2009), an emotion regulatory function for which there is empirical support (Chapman et al. 2006; Gratz 2007). Despite consistent reports of greater NSSI prevalence among adolescents compared to adults (Klonsky and Muehlenkamp 2007; Laye-Gindhu and Schonert-Reichl 2005), little research has examined NSSI among young adolescents (12–14 year), where it begins (Muehlenkamp and Gutierrez 2007; Nock 2009, 2010). The work that has been conducted with younger samples supports the contention that psychological distress is a risk factor for NSSI (Andrews et al. 2012, 2013; Baetens et al. 2012). Yet, not all individuals who experience psychological distress self-injure, suggesting underlying psychological processes that may differentiate individuals who do from those who
Prev Sci
engage in more adaptive forms of coping. While numerous individual differences have been implicated in this relationship (e.g., Di Pierro et al. 2012; Mullins-Sweat et al. 2013), rumination and optimism are two that are readily amenable to change. Should rumination pose a risk factor, and optimism a protective factor, this would inform models of NSSI which could then inform prevention research. The experiential avoidance model (Chapman et al. 2006) of NSSI suggests that individuals engage in NSSI in order to avoid unwanted emotional states. According to this model, an emotionally evocative event is purported to trigger an aversive emotional response, leading to the use of self-injury to reduce or eliminate emotional arousal, negatively reinforcing the behavior. In line with this, stronger experiential avoidance tendencies have been observed among individuals who engage in NSSI compared to those who do not (Gratz 2007; Gratz and Roemer 2004). Similarly, avoidance of negative thoughts may also serve as a motive for NSSI. Selby et al. (2008) propose that when individuals ruminate on negative affect, an emotional cascade occurs, the result of which is the amplification of negative affect. This cascade continues to the point where an individual utilizes NSSI as distraction from rumination (Selby et al. 2008). As such, rumination may be one factor that increases risk of NSSI in the presence of psychological distress. A growing literature supports that NSSI may be a temporarily effective method of ceasing rumination (e.g., Selby et al. 2007). Selby et al. (2009) reported rumination predicted NSSI frequency and moderated the association between past, painful, and provocative events and NSSI. Inclinations to selfinjure are mostly preceded by worry or recall of an aversive memory, rather than external interpersonal conflict or criticism (Nock et al. 2009). To the extent that negative thought maintains negative affect, NSSI may serve a cognitive regulation function in addition to emotion regulation (Najmi et al. 2007). High endorsement of worry and intrusive memories prior to NSSI implicates rumination as a key component in the relationship between psychological distress and NSSI. Although identifying factors that may increase risk of NSSI is important for early intervention efforts, factors which protect against NSSI may have greater utility in prevention programs. Unlike ruminating on past events, positive beliefs about the future (e.g., optimism, self-efficacy, and self-esteem) are thought to be related to proactive coping strategies and observed to be protective when individuals are facing life stressors (Aspinwall 2005; Aspinwall and Richter 1999; Aspinwall and Taylor 1997). Optimism, in particular, is thought to reduce the appraisal of stressful events as threatening or negative (Jerusalem 1993). Optimism, the extent to which an individual displays positive expectancies for the future (Scheier and Carver 1995), has been demonstrated to exert a protective influence on many correlates of psychological distress (e.g., negative life events; Sawyer et al. 2009), as well as reduce the
risk of depressive symptoms and substance abuse among adolescents (Patton et al. 2011). Even when distressed, individuals high in optimism are more likely to overcome adversity and to utilize adaptive rather than maladaptive coping strategies (Carver et al. 2010; Solberg Nes and Segerstrom 2006). Yet, despite the apparent ability of optimism to protect against psychological distress, there has been little examination of whether it confers resilience against self-injury. Research on suicidality provides indirect evidence that optimistic individuals are at lower risk for self-destructive behaviors. Optimism mitigates the influence of negative life events on suicidal ideation (Hirsch et al. 2009), moderates the relationship between hopelessness and suicidal ideation (Hirsch and Conner 2006), and is lower among individuals who self-harm (O’Connor et al. 2009). These findings reveal a trend toward better outcomes for individuals high in optimism across several domains. However, no studies specifically examining optimism as a moderator of psychological distress and NSSI have been found. Although the assumption that individuals with higher optimism are less vulnerable to NSSI holds intuitive appeal, it is currently unknown if this applies to adolescents experiencing psychological distress. The present study aimed to replicate past research on the relationship between psychological distress and NSSI. It also aimed to broaden the scope of previous research by simultaneously examining the influence of rumination and optimism on the relationship between psychological distress and NSSI. We hypothesized there would be a positive relationship between psychological distress and NSSI, and that rumination would moderate this, such that the proposed relationship between psychological distress and NSSI would be stronger at high levels of rumination. We predicted that optimism would moderate the relationship between psychological distress and NSSI, such that the proposed relationship between psychological distress and NSSI would be stronger at low levels of optimism.
Method Participants As part of a larger study on NSSI among adolescents, 115 schools from five Australian states were invited to participate; 41 agreed (23 Catholic and 18 independent, i.e., nongovernment). Parents of all students in selected grades (n =14,841) were sent information sheets. Of these 4,119 returned consent forms, 3,116 provided consent for their child’s participation (21 %). This response rate is consistent with previous Australian studies requiring active parental consent (Hasking et al. 2010; 20 % response rate). The participation of more girlsonly schools than boys or mixed gender schools resulted in an overrepresentation of girls in the sample (ABS 2012).
Prev Sci
The final sample comprised of 1,789 adolescent girls and 848 adolescent boys aged between 12 and 18 years of age (M =13.93, SD=0.99). Most participants were in their second (37.4 %) or third (30 %) year of secondary school (catering for 12–18 year olds), consistent with data indicating that these year levels have the highest percentage of students (both 27.4 %; ABS 2012). The majority (89.3 %) were born in Australia and 2.4 % identified as Aboriginal or Torres Strait Islander, again consistent with the national profile for adolescents (86.3 % Australian-born; 2.1 % Indigenous, ABS 2011, 2012). Participants were disproportionally recruited from areas of greater socioeconomic advantage (M =7.21, SD=2.37, scale 1–10; ABS 2008). Most (77 %) reported their parents were married. Previous diagnosis of mental illness was reported by 6.4 % of participants, most frequently major depression (25.80 %). Measures Sociodemographic Data In addition to age, gender, year at school, country of birth, parental marital status, and history of mental illness, participants provided their home post code (i.e., zip code). These were utilized to estimate geographic remoteness and socioeconomic status as computed from the Australian Bureau of Statistics (ABS) Remoteness Classification and Index of Relative Socioeconomic Advantage and Disadvantage (IRSAD; ABS 2006, 2008). The Remoteness Classification allows comparisons between metropolitan, regional, rural, and remote areas of Australia. The IRSAD is a general measure of socioeconomic status derived from a number of measures of advantage and disadvantage for a given geographical region (e.g., income, education level, employment). A low score indicates greater disadvantage and less advantage. Self-Harm Behavior Questionnaire The Self-Harm Behavior Questionnaire (SHBQ) (Gutierrez 1998) was developed to balance the depth of information obtained from clinical interviews with the convenience of self-report questionnaire and was designed to assess four theoretically distinct aspects of suicidal behavior (self-harm, past suicide attempts, suicide threat, suicide ideation). In the initial validation, factor analyses confirmed the presence of four district factors (Gutierrez et al. 2001), each calculated by summating items loading on that factor. NSSI was assessed by part A of the SHBQ, focused on intentional self-injury not suicidal in nature, which is valid for use with adolescents (Muehlenkamp et al. 2009). Respondents were asked, “Have you ever hurt yourself on purpose?” and were required to indicate the nature of the harm. They were then asked about the frequency, their age at first and most recent incident, and whether they had told anyone of the behavior, which produced a frequency (1 = once,
4 = 4 or more times), history (1 = 0–1 year, 4 = 6 or more years), and disclosure score (1 = yes, 2 = no), respectively, with blank responses scored as zero. Respondents rated severity of self-injury on a 4-point Likert scale (1 = not at all serious, 4 = life threatening). Coded responses were summed to produce a total NSSI score ranging from 0 (no NSSI) to 18 (recurrent and long-term NSSI). The SHBQ reliably differentiates youth with suicidal ideation from non-suicidal youth and correlates well with other measures of suicidality (Gutierrez et al. 2001). Cronbach’s alpha in the current study was 0.94, indicating excellent internal consistency. General Health Questionnaire The General Health Questionnaire (GHQ-12; Goldberg and Williams 1988) measures current mental health functioning, with an equal number of positively (“Been able to face up to your problems?”) and negatively (“Felt that you couldn’t overcome your difficulties?”) phrased questions, rated for the past few weeks on a 4-point Likert scale (1 = better than usual, 4 = much worse than usual). Total scores could range from 12 to 36. Designed as a screening tool for nonpsychotic psychiatric diagnoses in the general community, the GHQ has solid reliability (Cronbach’s alpha=0.88). While sensitivity among older Australian adolescents may be minimized relative to international samples (Tait et al. 2002), in school-based samples, the GHQ correlates well with measures of anxiety, stress, depression, and negative affectivity and demonstrates discriminant validity (Tait et al. 2003). Cronbach’s alpha for the present study was 0.89. Ruminative Thought Style Questionnaire The Ruminative Thought Style Questionnaire (RTSQ; Brinker and Dozois 2009) is a 20-item measure describing positive, negative, and neutral facets of global rumination (“I can’t stop thinking about some things;” “I have never been able to distract myself from unwanted thoughts”) suggested by its developers to be less biased by valence, content, or temporal orientation than traditional measures of rumination. Respondents rated each statement on a 7-point Likert scale (1 = not at all descriptive of me, 7 = describes me very well). Total scores could range from 20 to 140. The RTSQ has good convergent validity with the Response Style Questionnaire, the Global Rumination Scale, and the Beck Depression Inventory, adequate test–retest reliability and high internal consistency (Brinker and Dozois 2009). Cronbach’s alpha for the present sample was excellent (α=0.94). Revised Version of the Life Orientation Test The revised version of the Life Orientation Test (Scheier et al. 1994) measures optimism. Six items measure generalized
Prev Sci
expectancies for positive and negative outcomes. Half the statements are positively worded (“In uncertain times, I usually expect the best”) and half negatively (“I hardly ever expect things to go my way”). Respondents indicated agreement on a 5-point Likert scale (1 = strongly disagree, 5 = strongly agree). Negatively worded items were reverse scored and summated to yield an overall optimism score ranging from 6–30; higher scores indicate greater optimism. Adequate test–retest reliability (0.43 to 0.63) and convergent and discriminant validity with related scales have been reported (Scheier et al. 1994). Cronbach’s alpha in this sample was sound (α=0.74). Procedure After obtaining IRB approval from Monash University and the University of Queensland, schools distributed explanatory statements and consent forms to parents. Children with parent/ guardian consent completed the 1-h questionnaire at school. Participants were notified that they could withdraw from the study at any time, and supplied a unique code to facilitate confidentiality, yet enable identification in the event researchers identified high-risk behaviors. On completion, participants received information about mental health resources.
Results Data Screening Prior to analyses, data were screened for missing values and outliers. This resulted in the exclusion of 65 cases of missing data on entire scales. Forty-six cases were univariate outliers (standardized Z-scores±3.29) each scoring highly on the SHBQ, and were retained as cases representative of the population of interest (Orr et al. 1991). Although 214 multivariate outliers were identified, none possessed a Cook’s or Leverage value greater than 1, and were not overly influential (Tabachnick and Fidell 2007). While cases with no data on the key variables were excluded, expectation–maximization was used to impute individual missing values (0.05. NSSI scores ranged from 3 to 15 (11.94±1.62) among those who reported a history of NSSI, with most common methods being cutting with a sharp object (61 %) and hitting the self with fists or other objects (17 %). The majority (76 %) reported first self-injuring between 12 and 14 years (12.08±3.42), and 24 % had self-injured more than five times. Half (49.8 %) of self-injuring adolescents did not require first aid, and most (86 %) did not seek medical attention. Half (49.6 %) had seen a mental health professional, and 21.6 % had been diagnosed with a mental illness. No differences in NSSI score existed between boys (11.84±1.67) and girls (12.03 ±1.46) who self-injured, t (243)= −0.90, p >0.05. Self-injury was positively related to psychological distress and rumination (Table 1), and negatively related to optimism. Psychological distress was positively correlated with rumination, and negatively correlated with optimism. Rumination was negatively correlated with optimism. Hierarchical Multiple Regression Multilevel modeling using a generalized mixed model was used to assess the possible influence of clustering on NSSI. After accounting for state, urbanicity (metropolitan or regional), and school within a regression model, similar parameter estimates for the factors of interest were found. However, information criterion and likelihood ratio tests suggest the mixed model with random intercepts was preferred over the original model (AIC: 13,404.45 vs. 13,720.93, p
Effects of Rumination and Optimism on the Relationship Between Psychological Distress and Non-Suicidal Self-Injury Alicia K. Tanner & Penelope Hasking & Graham Martin
# Society for Prevention Research 2013
Abstract In recent years, increasing concern regarding nonsuicidal self-injury (NSSI) among adolescents has prompted investigation of factors that may prevent this behavior. This study examined the relationship between psychological distress and NSSI in a community sample of adolescents, and the moderating effect of both optimism and rumination on this association. Two thousand five hundred seventy-two participants (12–18 years) completed self-report questionnaires assessing psychological distress, cognitive, and emotional characteristics, and NSSI history. Ten percent of the sample reported a history of NSSI, and as hypothesized, optimism moderated the relationship between psychological distress and NSSI; the association was only evident when optimism was low. Rumination was not found to moderate the relationship between psychological distress and NSSI. These findings highlight the utility of considering optimism in NSSI prevention and early intervention programs. Keywords Self-injury . NSSI . Rumination . Optimism . Psychological distress Non-suicidal self-injury (NSSI), the purposeful destruction of one’s own body tissue without conscious suicidal intent (Nock and Favazza 2009), is a prevalent behavior and the single greatest risk factor for future self-injury and suicide (Skegg 2005). Current prevalence estimates range between 9 and 45 % (Lloyd-Richardson et al. 2007; Martin et al. 2010; Plener et al. 2009). Given that NSSI is as a prominent threat to A. K. Tanner : P. Hasking (*) School of Psychology and Psychiatry, Monash University, Clayton 3800, VIC, Australia e-mail: [email protected] G. Martin Center for Clinical Psychiatry and Neuroscience, The University of Queensland, Brisbane, Australia
physical health and psychological functioning in adolescence (Hawton and James 2005) and may precipitate suicidality (Nock et al. 2006), further research is needed to clarify individual vulnerabilities for NSSI and to identify psychological processes that may influence these associations. Although individuals with psychological impairment are at greater risk of NSSI (Martin et al. 2010; Williams and Hasking 2010), such outcomes are not inexorable, and examining factors that may confer resilience to NSSI is imperative for development of effective NSSI intervention and prevention strategies. In this paper, we explore the roles of rumination and optimism in the relationship between psychological distress and NSSI with a view to identifying psychological factors that may increase risk of, or protect against, NSSI. Self-injurers report higher levels of subjective distress in response to aversive or stressful experiences (Najmi et al. 2007; Skegg 2005), and higher prevalence of depressive and anxiety disorders (Klonsky et al. 2003). The high emotional reactivity and dysregulation that characterizes several psychiatric conditions has been proposed as a causal mechanism associating these disorders with NSSI (Klonsky and Muehlenkamp 2007); people may self-injure to cope with this elevated distress (Nock 2009), an emotion regulatory function for which there is empirical support (Chapman et al. 2006; Gratz 2007). Despite consistent reports of greater NSSI prevalence among adolescents compared to adults (Klonsky and Muehlenkamp 2007; Laye-Gindhu and Schonert-Reichl 2005), little research has examined NSSI among young adolescents (12–14 year), where it begins (Muehlenkamp and Gutierrez 2007; Nock 2009, 2010). The work that has been conducted with younger samples supports the contention that psychological distress is a risk factor for NSSI (Andrews et al. 2012, 2013; Baetens et al. 2012). Yet, not all individuals who experience psychological distress self-injure, suggesting underlying psychological processes that may differentiate individuals who do from those who
Prev Sci
engage in more adaptive forms of coping. While numerous individual differences have been implicated in this relationship (e.g., Di Pierro et al. 2012; Mullins-Sweat et al. 2013), rumination and optimism are two that are readily amenable to change. Should rumination pose a risk factor, and optimism a protective factor, this would inform models of NSSI which could then inform prevention research. The experiential avoidance model (Chapman et al. 2006) of NSSI suggests that individuals engage in NSSI in order to avoid unwanted emotional states. According to this model, an emotionally evocative event is purported to trigger an aversive emotional response, leading to the use of self-injury to reduce or eliminate emotional arousal, negatively reinforcing the behavior. In line with this, stronger experiential avoidance tendencies have been observed among individuals who engage in NSSI compared to those who do not (Gratz 2007; Gratz and Roemer 2004). Similarly, avoidance of negative thoughts may also serve as a motive for NSSI. Selby et al. (2008) propose that when individuals ruminate on negative affect, an emotional cascade occurs, the result of which is the amplification of negative affect. This cascade continues to the point where an individual utilizes NSSI as distraction from rumination (Selby et al. 2008). As such, rumination may be one factor that increases risk of NSSI in the presence of psychological distress. A growing literature supports that NSSI may be a temporarily effective method of ceasing rumination (e.g., Selby et al. 2007). Selby et al. (2009) reported rumination predicted NSSI frequency and moderated the association between past, painful, and provocative events and NSSI. Inclinations to selfinjure are mostly preceded by worry or recall of an aversive memory, rather than external interpersonal conflict or criticism (Nock et al. 2009). To the extent that negative thought maintains negative affect, NSSI may serve a cognitive regulation function in addition to emotion regulation (Najmi et al. 2007). High endorsement of worry and intrusive memories prior to NSSI implicates rumination as a key component in the relationship between psychological distress and NSSI. Although identifying factors that may increase risk of NSSI is important for early intervention efforts, factors which protect against NSSI may have greater utility in prevention programs. Unlike ruminating on past events, positive beliefs about the future (e.g., optimism, self-efficacy, and self-esteem) are thought to be related to proactive coping strategies and observed to be protective when individuals are facing life stressors (Aspinwall 2005; Aspinwall and Richter 1999; Aspinwall and Taylor 1997). Optimism, in particular, is thought to reduce the appraisal of stressful events as threatening or negative (Jerusalem 1993). Optimism, the extent to which an individual displays positive expectancies for the future (Scheier and Carver 1995), has been demonstrated to exert a protective influence on many correlates of psychological distress (e.g., negative life events; Sawyer et al. 2009), as well as reduce the
risk of depressive symptoms and substance abuse among adolescents (Patton et al. 2011). Even when distressed, individuals high in optimism are more likely to overcome adversity and to utilize adaptive rather than maladaptive coping strategies (Carver et al. 2010; Solberg Nes and Segerstrom 2006). Yet, despite the apparent ability of optimism to protect against psychological distress, there has been little examination of whether it confers resilience against self-injury. Research on suicidality provides indirect evidence that optimistic individuals are at lower risk for self-destructive behaviors. Optimism mitigates the influence of negative life events on suicidal ideation (Hirsch et al. 2009), moderates the relationship between hopelessness and suicidal ideation (Hirsch and Conner 2006), and is lower among individuals who self-harm (O’Connor et al. 2009). These findings reveal a trend toward better outcomes for individuals high in optimism across several domains. However, no studies specifically examining optimism as a moderator of psychological distress and NSSI have been found. Although the assumption that individuals with higher optimism are less vulnerable to NSSI holds intuitive appeal, it is currently unknown if this applies to adolescents experiencing psychological distress. The present study aimed to replicate past research on the relationship between psychological distress and NSSI. It also aimed to broaden the scope of previous research by simultaneously examining the influence of rumination and optimism on the relationship between psychological distress and NSSI. We hypothesized there would be a positive relationship between psychological distress and NSSI, and that rumination would moderate this, such that the proposed relationship between psychological distress and NSSI would be stronger at high levels of rumination. We predicted that optimism would moderate the relationship between psychological distress and NSSI, such that the proposed relationship between psychological distress and NSSI would be stronger at low levels of optimism.
Method Participants As part of a larger study on NSSI among adolescents, 115 schools from five Australian states were invited to participate; 41 agreed (23 Catholic and 18 independent, i.e., nongovernment). Parents of all students in selected grades (n =14,841) were sent information sheets. Of these 4,119 returned consent forms, 3,116 provided consent for their child’s participation (21 %). This response rate is consistent with previous Australian studies requiring active parental consent (Hasking et al. 2010; 20 % response rate). The participation of more girlsonly schools than boys or mixed gender schools resulted in an overrepresentation of girls in the sample (ABS 2012).
Prev Sci
The final sample comprised of 1,789 adolescent girls and 848 adolescent boys aged between 12 and 18 years of age (M =13.93, SD=0.99). Most participants were in their second (37.4 %) or third (30 %) year of secondary school (catering for 12–18 year olds), consistent with data indicating that these year levels have the highest percentage of students (both 27.4 %; ABS 2012). The majority (89.3 %) were born in Australia and 2.4 % identified as Aboriginal or Torres Strait Islander, again consistent with the national profile for adolescents (86.3 % Australian-born; 2.1 % Indigenous, ABS 2011, 2012). Participants were disproportionally recruited from areas of greater socioeconomic advantage (M =7.21, SD=2.37, scale 1–10; ABS 2008). Most (77 %) reported their parents were married. Previous diagnosis of mental illness was reported by 6.4 % of participants, most frequently major depression (25.80 %). Measures Sociodemographic Data In addition to age, gender, year at school, country of birth, parental marital status, and history of mental illness, participants provided their home post code (i.e., zip code). These were utilized to estimate geographic remoteness and socioeconomic status as computed from the Australian Bureau of Statistics (ABS) Remoteness Classification and Index of Relative Socioeconomic Advantage and Disadvantage (IRSAD; ABS 2006, 2008). The Remoteness Classification allows comparisons between metropolitan, regional, rural, and remote areas of Australia. The IRSAD is a general measure of socioeconomic status derived from a number of measures of advantage and disadvantage for a given geographical region (e.g., income, education level, employment). A low score indicates greater disadvantage and less advantage. Self-Harm Behavior Questionnaire The Self-Harm Behavior Questionnaire (SHBQ) (Gutierrez 1998) was developed to balance the depth of information obtained from clinical interviews with the convenience of self-report questionnaire and was designed to assess four theoretically distinct aspects of suicidal behavior (self-harm, past suicide attempts, suicide threat, suicide ideation). In the initial validation, factor analyses confirmed the presence of four district factors (Gutierrez et al. 2001), each calculated by summating items loading on that factor. NSSI was assessed by part A of the SHBQ, focused on intentional self-injury not suicidal in nature, which is valid for use with adolescents (Muehlenkamp et al. 2009). Respondents were asked, “Have you ever hurt yourself on purpose?” and were required to indicate the nature of the harm. They were then asked about the frequency, their age at first and most recent incident, and whether they had told anyone of the behavior, which produced a frequency (1 = once,
4 = 4 or more times), history (1 = 0–1 year, 4 = 6 or more years), and disclosure score (1 = yes, 2 = no), respectively, with blank responses scored as zero. Respondents rated severity of self-injury on a 4-point Likert scale (1 = not at all serious, 4 = life threatening). Coded responses were summed to produce a total NSSI score ranging from 0 (no NSSI) to 18 (recurrent and long-term NSSI). The SHBQ reliably differentiates youth with suicidal ideation from non-suicidal youth and correlates well with other measures of suicidality (Gutierrez et al. 2001). Cronbach’s alpha in the current study was 0.94, indicating excellent internal consistency. General Health Questionnaire The General Health Questionnaire (GHQ-12; Goldberg and Williams 1988) measures current mental health functioning, with an equal number of positively (“Been able to face up to your problems?”) and negatively (“Felt that you couldn’t overcome your difficulties?”) phrased questions, rated for the past few weeks on a 4-point Likert scale (1 = better than usual, 4 = much worse than usual). Total scores could range from 12 to 36. Designed as a screening tool for nonpsychotic psychiatric diagnoses in the general community, the GHQ has solid reliability (Cronbach’s alpha=0.88). While sensitivity among older Australian adolescents may be minimized relative to international samples (Tait et al. 2002), in school-based samples, the GHQ correlates well with measures of anxiety, stress, depression, and negative affectivity and demonstrates discriminant validity (Tait et al. 2003). Cronbach’s alpha for the present study was 0.89. Ruminative Thought Style Questionnaire The Ruminative Thought Style Questionnaire (RTSQ; Brinker and Dozois 2009) is a 20-item measure describing positive, negative, and neutral facets of global rumination (“I can’t stop thinking about some things;” “I have never been able to distract myself from unwanted thoughts”) suggested by its developers to be less biased by valence, content, or temporal orientation than traditional measures of rumination. Respondents rated each statement on a 7-point Likert scale (1 = not at all descriptive of me, 7 = describes me very well). Total scores could range from 20 to 140. The RTSQ has good convergent validity with the Response Style Questionnaire, the Global Rumination Scale, and the Beck Depression Inventory, adequate test–retest reliability and high internal consistency (Brinker and Dozois 2009). Cronbach’s alpha for the present sample was excellent (α=0.94). Revised Version of the Life Orientation Test The revised version of the Life Orientation Test (Scheier et al. 1994) measures optimism. Six items measure generalized
Prev Sci
expectancies for positive and negative outcomes. Half the statements are positively worded (“In uncertain times, I usually expect the best”) and half negatively (“I hardly ever expect things to go my way”). Respondents indicated agreement on a 5-point Likert scale (1 = strongly disagree, 5 = strongly agree). Negatively worded items were reverse scored and summated to yield an overall optimism score ranging from 6–30; higher scores indicate greater optimism. Adequate test–retest reliability (0.43 to 0.63) and convergent and discriminant validity with related scales have been reported (Scheier et al. 1994). Cronbach’s alpha in this sample was sound (α=0.74). Procedure After obtaining IRB approval from Monash University and the University of Queensland, schools distributed explanatory statements and consent forms to parents. Children with parent/ guardian consent completed the 1-h questionnaire at school. Participants were notified that they could withdraw from the study at any time, and supplied a unique code to facilitate confidentiality, yet enable identification in the event researchers identified high-risk behaviors. On completion, participants received information about mental health resources.
Results Data Screening Prior to analyses, data were screened for missing values and outliers. This resulted in the exclusion of 65 cases of missing data on entire scales. Forty-six cases were univariate outliers (standardized Z-scores±3.29) each scoring highly on the SHBQ, and were retained as cases representative of the population of interest (Orr et al. 1991). Although 214 multivariate outliers were identified, none possessed a Cook’s or Leverage value greater than 1, and were not overly influential (Tabachnick and Fidell 2007). While cases with no data on the key variables were excluded, expectation–maximization was used to impute individual missing values (0.05. NSSI scores ranged from 3 to 15 (11.94±1.62) among those who reported a history of NSSI, with most common methods being cutting with a sharp object (61 %) and hitting the self with fists or other objects (17 %). The majority (76 %) reported first self-injuring between 12 and 14 years (12.08±3.42), and 24 % had self-injured more than five times. Half (49.8 %) of self-injuring adolescents did not require first aid, and most (86 %) did not seek medical attention. Half (49.6 %) had seen a mental health professional, and 21.6 % had been diagnosed with a mental illness. No differences in NSSI score existed between boys (11.84±1.67) and girls (12.03 ±1.46) who self-injured, t (243)= −0.90, p >0.05. Self-injury was positively related to psychological distress and rumination (Table 1), and negatively related to optimism. Psychological distress was positively correlated with rumination, and negatively correlated with optimism. Rumination was negatively correlated with optimism. Hierarchical Multiple Regression Multilevel modeling using a generalized mixed model was used to assess the possible influence of clustering on NSSI. After accounting for state, urbanicity (metropolitan or regional), and school within a regression model, similar parameter estimates for the factors of interest were found. However, information criterion and likelihood ratio tests suggest the mixed model with random intercepts was preferred over the original model (AIC: 13,404.45 vs. 13,720.93, p
