Population
Data were collected between 2018 and 2021 in an outpatient unit specialized in the assessment and treatment of borderline personality disorder (BPD) and adult attention deficit hyperactivity disorder (ADHD), the TRE Unit, in the University Hospitals of Geneva, in Switzerland. Patients are usually referred by their general practitioner, psychiatrist, psychologist, or other mental health care professional for one or both disorders.
The inclusion criteria for participation in the present study were: 1°) Being referred to the unit for assessment and/or care of adult ADHD, BPD, or emotion dysregulation 2°) Being at least 18 years old 3°) Having a diagnosis of BPD made with the SCID-5-PD and 4°) Providing informed consent for participation in the study and use of health data for research purposes. The study was approved by the Ethics Committee of the Geneva University Hospitals.
Procedure
Patients were assessed for BPD using the Structured Clinical Interview for DSM-IV Personality Disorders, adapted for DSM-5 (SCID-5-PD, (28)). The SCID-5-PD was administered by trained psychologists. Each criterium was noted as present or absent, and if a minimum of five out of nine criteria was met, the BPD diagnosis was made. Other psychiatric disorders were clinically assessed, including major depressive disorder, bipolar disorder, anxiety disorder, obsessive-compulsive disorder, post-traumatic stress disorder, autism spectrum disorder, and substance use disorder. Medical records and information provided by other clinicians involved in patients’ care were reviewed in order to assess the lifetime comorbidities.
Assessment of NSSI behaviors, body modifications and suicidal behaviors. We designed a new scale for this study, the Suicidal Behavior and Body Damage & Modifications Scale (SBBDM-S), to assess the lifetime presence of NSSI and BMs. The SBBDM-S is a 10-items self-report questionnaire used to investigate the lifetime prevalence and the past number of suicidal behaviors, body modifications (including tattoos and piercing) and/or NSSI. The translated questionnaire is available in the [Additional File 1]. The suicidal behaviors are studied in question 1 to 4 (with the question 1 and 2 assessing respectively the lifetime presence and the number of suicide attempts, question 3 assessing the age when the first suicide attempt occurred, and question 4 assessing the method used in the most serious attempt). Body modifications are studied in questions 5 to 8 (with question 5 and 7 assessing respectively the lifetime acquisition of a tattoo and of a piercing by a professional (including earlobe piercing), the question 6 assessing the tattoo-covered body surface percentage (< 10%, 10–50%, 50–90%, > 90%), and the question 8 assessing the total number of piercings). The NSSI were assessed in question 9 and 10 (question 9 assessing the lifetime presence of NSSI, and question 10 assessing the number of times each type of NSSI type occurred). The total number of NSSI was calculated by summing all the individual numbers of times each type of NSSI occurred.
For the purposes of the analyses, we defined three sub-scores: the total number of piercings, the tattoo-covered body surface percentage, and the total score of body modifications. For the rest of the article, these three subscores will be named as PercTot, TatTot and BMTot, respectively. These three subscores were treated as ordinal scales. For PercTot, the original scale had the following characteristics: mean = 2.89, SD = 3.44 and median [range] = 1 [0–15]. Given the low number of patients in the higher categories, the scale was treated as follows in order to balance the number of patients across groups: 0 = no piercing (N = 34), 1 = one piercing (N = 21), 2 = two piercings (N = 16), 3 = three or more piercings (N = 45). For TatTot, the original scale had the following characteristics: mean = 0.95, SD = 0.79 and median [range] = 1 [0–3]. Once again, the scale was reduced to a three-point ordinal scale, and the tattoo-covered body surface percentage of > 10%, 50–90% and > 90% were put together as follows: 0 = no tattoo(N = 35), 1 = less than 10% of the body covered (N = 55), 2 = more than 10% of the body covered (N = 26). Finally, for BMTot, corresponding to the sum of the original PercTot & TatTot scores, the original scale had the following characteristics: mean = 3.84, SD = 3.69 and median = 2 [0–17]. Only 25 subjects had a score above six and were thus regrouped with those having a score of 6 on a seven-point ordinal scale, from 0 (N = 17) to > = 6 (N = 27). Finally, the second item of the SBBDM-S was used to assess the total number of suicide attempts.
Assessment of psychopathological domains
For BPD severity, the French version of the Borderline Symptom List – 23 items (BSL-23) was used (29, 30) The BSL-23 questionnaire is a self-report questionnaire used to investigate the global severity of BPD symptoms, and it is also used to estimate the effect of therapy in BPD patients. It consists in 23 items investigating the last week’s symptomatic experience of BPD patients, with a 5-point Likert response format (from 0 (“never”) to 4 (“always”)), and the mean score is calculated. A classification of BPD severity was recently proposed based on the mean score at the BSL-23 (31).
For emotion regulation, the French versions of the Difficulties in Emotion Regulation Scale – 18 items (DERS-18 ; (32)) and of the Cognitive Emotion Regulation Questionnaire (CERQ, (33, 34)) were used. The DERS-18 is a self-report questionnaire, the short form created in 2016 of the original DERS, and assesses in the last month the intensity of different domains of emotion regulation: lack of awareness of one’s emotions (awareness), lack of clarity about the nature of one’s emotions (clarity), lack of ability to engage in goal-directed activities during negative emotions (goals), lack of ability to manage one’s impulses during negative emotions (impulse), lack of acceptance of one’s emotions (nonacceptance) and lack of access to effective emotion regulation strategies (strategies). It consists in 18 items relative to the presence of these domains, with a 5-point Likert response format (from 1 (“almost never”) to 5 (“almost always”)), and the sub-scores were made following the original article recommendations. Also, a total score can be calculated by summing all the subscores, with a higher score indicating greater difficulties with emotion regulation. For this study, we only considered the DERS total score. On the other side, the CERQ is a self-report questionnaire, assessing 9 different emotion regulation strategies: acceptance, positive refocusing, refocus on planning, positive reappraisal, putting into perspective, blame, rumination, catastrophizing and blaming others. It consists in 36 items relative to these domains, with a 5-point Likert response format (from 1 (“almost never”) to 5 (“almost always”)). Five of these strategies (acceptance, positive refocusing, refocus on planning, positive reappraisal, putting into perspective) can be summed in a CERQ adaptative sub-score, while the remaining four (blame, rumination, catastrophizing and blaming others) can be summed in a CERQ non-adaptative sub-score. For this study, we only considered the CERQ adaptative and non-adaptative subscores.
For impulsivity, the French version of the short form of the UPPS-P Impulsive Behavior Scale (35, 36) was used. The UPPS-P is a self-report questionnaire assessing five domains of impulsivity: negative urgency, positive urgency, lack of premeditation, lack of perseverance and sensation seeking. It consists in 20 items related to these domains, with a 4-point Likert response format (from 1 (“totally agree”) to 4 (“totally disagree”)), and the sub-scores were made following the original article recommendations.
For depressive symptoms, the French version of the Beck Depression Inventory was used (BDI, (37, 38). The BDI is a self-report questionnaire assessing the intensity of depressive symptoms, and consists in 21 items, with a 4-point Likert response format.
For anxiety, the French version of the State Trait Anxiety Inventory (STAI, (39) was used. The STAI is a 40 items self-report questionnaire assessing the intensity of anxiety as a trait (i.e. generally, 20 items with a 4-point Likert response format) and as a state (i.e. these days, 20 items with a 4-point Likert response format). For this study, we only considered the STAI-trait score.
Statistical analyses
We used ordinal logistic regression to test the associations between body modification variables (PercTot, TatTot, BMtot) treated as ordinal scales and clinical variables (history of suicide attempts, NSSI, SCID total score, BSL-23, BDI, STAI, CERQ adaptive and non-adaptive subscales, DERS total score, UPPS-P subscales). We adjusted our models on age and gender when required. As we conducted several tests (one for each non-correlated variable, with the CERQ subscales, the UPPS-P subscales, and the three BMs variables being correlated variables, n = 10) for the same dependent variables, statistical significance was accepted for p values < 0.05/10 = 0.005. We also examined the correlation between variables using Spearman's correlations. Analyses were conducted with StataSE 16.0 (40).