LAS ESTRATEGIAS INICIALES

The Inventory of Statements about Self-Injury (ISAS) is a comprehensive self- report measure of non-suicidal self-injury (Appendix E). It comprises two distinct sections: Section I. Behaviours assesses the act of NSSI; whilst Section II. Functions measures the functions of behaviour (Klonsky & Olino, 2008; Klonsky & Glenn, 2009). The ISAS has been employed to assess nonsuicidal self-injurious behaviours across a broad range of different populations, from high school students (Bildik, Somer, Kabukçu Başay, Başay, & Özbaran, 2013; Oktan, 2014, 2015), college students (Batejan, Swenson, Jarvi, & Muehlenkamp, 2015; Glenn, Blumenthal, Klonsky, & Hajcak, 2011; Glenn & Klonsky, 2010a, 2010b; Hamza & Willoughby, 2014; Klonsky & Olino, 2008), to clinical samples (Klonsky, Glenn, Styer, Olino, & Washburn, 2015; Sadeh et al., 2014), young women in residential care (Lindholm, Bjärehed, & Lundh, 2011) and transgender adults (Dickey, Reisner, & Juntunen, 2015). A number of studies have been undertaken to explicitly investigate the psychometric properties of the ISAS

148 (Glenn & Klonsky, 2011; Klonsky & Glenn, 2009; Klonsky & Olino, 2008; Kortge, Meade, & Tennant, 2013; Latimer, Meade, & Tennant, 2013). Finally, it has also been translated and found psychometrically sound in Turkish (Bildik et al., 2013; Oktan, 2014, 2015) and Swedish samples (Lindholm et al., 2011).

8.2.3.1 Inventory of Statements about Self-Injury: Section I. Behaviours The first section of the ISAS measures the lifetime frequency of the following types of 12 self-injurious behaviours: cutting, biting, burning, carving, pinching, pulling hair, severe scratching, banging or hitting self, interfering with wound healing, rubbing skin against rough surfaces, sticking self with needles and swallowing dangerous substances. The questionnaire specifies that behaviours should only be endorsed if they have been undertaken intentionally and without suicidal intent. In the paper version, participants are asked to estimate the number of times they have engaged in each of the 12 behaviours over their lifetime. As the current study was presented in an online format, a sliding scale was incorporated into the questionnaire design and participants moved the scale from 0 to 100 to indicate their lifetime frequency of each behaviour. Participants also have the option of listing any other self-injurious behaviours that they have engaged in, under the item “other”. If at least one of these 12 behaviours is endorsed, participants are asked to complete a further five questions in this section eliciting additional descriptive and situational information about the act of NSSI (age of onset; most recent NSSI; physical pain associated with NSSI; whether the behaviour occurs alone or in the presence of others; duration of the urge to self-injure prior to engagement; and desire to stop). The latter four questions are presented in a multiple- choice format (Klonsky & Olino, 2008; Klonsky & Glenn, 2009).

149 The psychometric properties of the 12 behaviours of the ISAS were initially evaluated in a sample of 761 college students. With Cronbach’s alpha of .84, the self- injurious behaviours demonstrated good internal consistency (Klonsky & Olino, 2008). Test-retest reliability assessed at four weeks (n = 59) was strong at .85, whilst the median test-retest reliability at 12 months (n = 51) was not as robust with a median of .68 (Glenn & Klonsky, 2011).

The construct validity for this section of the ISAS was evaluated utilising the McLean Screening Instrument for Borderline Personality Disorder (MSI-BPD: Zanarini et al., 2003) and the Youth Risk Behaviours Survey (YRBS: Kann, 2001). Stronger correlations (α = .001) were found between the suicide/self-harm item (r = .45) of the MSI-BPD than with any of the other items of the MSI-BPD scale (median r = .21). Whilst moderate correlations were found between the MSI-BPD (omitting the self- harm/suicide item; r = .37); the suicidal ideation (r = .38) and the attempted suicide (r = .28) items of the YRBS, supporting the construct validity of this section of the ISAS (Klonsky & Olino, 2008).

8.2.3.2 Inventory of Statements about Self-Injury: Section II. Functions Section two consists of 39 reasons (items) for engaging in NSSI, which form the 13 function scales: affect regulation; anti-dissociation; anti-suicide; autonomy;

interpersonal boundaries; interpersonal influence; marking distress; peer bonding; revenge; self-care; self-punishment; sensation seeking; and toughness. Each of the 13 scales comprises three items, which are rated on a three point Likert scale, ranging from 0 = not relevant to 2 = very relevant. Each item starts with the statement “When I self- harm, I am...” (e.g., “calming myself down”; “punishing myself”; “fitting in with

150 others”). Scores for each of the 13 functions range from 0 to 6, with higher scores representing the more frequent occurrence of NSSI to manage that particular function (Glenn & Klonsky, 2011; Klonsky & Glenn, 2009; Klonsky & Olino, 2008). Mean total scores for the ISAS have ranged from 14.3 (SD = 13.3; Klonsky & Glenn, 2008) to 26.24 (SD = 9.90; Kortge et al., 2013). There are two optional open-ended questions at the end of the inventory that invite participants to list any other statements they believe are more reflective of their experience; or that they believe should be added to the list (Klonsky & Olino, 2008; Klonsky & Glenn, 2009).

Test-retest reliabilities of the 13 function scales over 12 months were all positive and significant, with a median of .59 (Glenn & Klonsky, 2011). Internal consistency has not been calculated for the overall ISAS functions scale to date in English. However, in its Turkish translation, Bildik et al. (2013) reported high internal consistency at .93 for the complete ISAS functions scale.

Klonsky and Glenn (2009) advocated a two-factor structural model with an inter personal and intrapersonal dichotomy. Initially, the two factors were calculated by summing each of the function scales and dividing each total by the number of subscales that comprised it; eight for the interpersonal scale (autonomy, interpersonal boundaries, interpersonal influence, peer-bonding, revenge, self-care, sensation seeking, and

toughness) and five for the intrapersonal scale (affect regulation, anti-dissociation, anti- suicide, marking distress, and self-punishment). Coefficient alphas of .87 and .80, respectively were found.

Klonsky, Glenn, Styer, Olino, and Washburn (2015) recently revised the

computation of these factors, recommending the summation of all the individual items, rather than the function scale scores, to form the intrapersonal and interpersonal or

151 Social factors. Scores on the intrapersonal scale range from 0 to 26, whilst the

interpersonal scale ranges from 0 to 36. This method of calculation yielded stronger internal consistencies with coefficient alphas of .89 for the social interpersonal factor and .88 for the intrapersonal factor (Klonsky et al., 2015). Replicating this calculation in larger samples, Kortge et al. (2013) and Batejan et al. (2015) reported internal consistencies of .87 and .86 for the interpersonal factor; and .77 and .81 for the intrapersonal factor, respectively. In the current study, the 39 items of the ISAS

demonstrated excellent internal consistency (α = .90), whilst the Cronbach’s alphas for the 15 Intrapersonal and 24 Interpersonal factors were strong at .95 and .87, respectively (see Appendix N). Test-retest correlations of .82 for the interpersonal factor and .60 for the intrapersonal factor have been reported across a 12 month period in a small sample of university students (Glenn & Klonsky, 2011).

The ISAS function scales have demonstrated sound construct validity with higher scores on interpersonal or intrapersonal functions correlated with higher scores on clinical measures, including the Depression Anxiety Stress Scales (DASS-21), The McLean Screening Instrument for Borderline Personality Disorder (MSI-BPD), and the Youth Risk Behaviours Survey (YRBS) (Klonsky & Glenn, 2009; Kortge, et al., 2013).

The researchers developed a number of additional questions which were incorporated into this online survey block. Participants were then asked “Have you EVER intentionally (i.e., on purpose) and without suicidal intent (i.e., not for suicidal reasons) harmed yourself?” Participants who indicated they had never engaged in NSSI entered a skip logic and were not required to respond to any further questions about NSSI, including the ISAS. Embedded within or following the ISAS were a range of questions designed by the researcher to gain a more comprehensive understanding of

152 NSSI (e.g., frequency, severity, sources of potential exposure to NSSI, routines or rituals, the number of people known who self-injure prior to onset: see Appendix H for the complete list of questions developed by the researcher on NSSI).