Personality Disorder Pathology Research Articles

Competing Models of Personality Disorder: Relations With Psychosocial Functioning.

The Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5; American Psychiatric Association, 2013), includes 10 categorical personality disorders (PD) in Section II (Section II PD) and a dimensional alternative model of PD (AMPD) in Section III. We compared the two models in explaining concurrent psychosocial functioning levels in psychiatric outpatients and community residents screened as at risk for PD pathology (N = 600). The AMPD's fully dimensional form showed stronger associations with psychosocial difficulties and explained more of their variance compared with the categorical Section II PD. AMPD Criterion A (personality functioning impairment) and Criterion B (pathological traits) incrementally predicted psychosocial functioning about equally with some unique predictions. Finally, AMPD's six categorical PD diagnoses did not show stronger associations with psychosocial functioning than the corresponding Section II PD diagnoses. Findings directly comparing the two models remain important and timely for informing future conceptualizations of PD in the diagnostic system.

Clarifying the relation between mother and adolescent borderline personality disorder symptoms: The roles of maternal and adolescent emotion regulation and maladaptive maternal emotion socialization.

Despite evidence for the intergenerational transmission of borderline personality disorder (BPD) pathology from mothers to offspring, the factors underlying the relation between mother and child BPD symptoms remain unclear and little is known about the pathways through which maternal BPD symptoms may relate to BPD symptoms in their offspring. One set of factors that warrants consideration in this regard is mother and child emotion regulation (ER) difficulties. In particular, theory and research suggest an indirect relation between mother and child BPD symptoms through maternal ER difficulties (and related maladaptive emotion socialization strategies) and, subsequently, child ER difficulties. Thus, this study used structural equation modeling to examine a model wherein maternal BPD symptoms relate to offspring BPD symptoms in adolescence through maternal ER difficulties (and maladaptive maternal emotion socialization strategies) and, subsequently, adolescent ER difficulties. A nationwide community sample of 200 mother-adolescent dyads completed an online study. Results provided support for the proposed model, revealing both a direct relation between maternal and adolescent BPD symptoms and two indirect relations through (a) maternal and adolescent ER difficulties and (b) maternal ER difficulties, maternal maladaptive emotion socialization strategies, and adolescent ER difficulties. Results highlight the relevance of both mother and adolescent ER difficulties in the relation between mother and offspring BPD pathology, as well as the potential clinical utility of targeting mother and child ER in interventions aimed at preventing the intergenerational transmission of BPD pathology. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

THE EFFECT OF LIFESPAN TRAUMA EXPOSURE ON PATHOLOGICAL PERSONALITY TRAITS

Abstract Introduction The Alternative Model of Personality Disorders (AMPD) is a dimensional model of personality disorder pathology focusing on pathological personality traits, with five trait domains. Limited knowledge exists about relationships between cumulative exposure to traumatic events and the AMPD, a gap particularly relevant for older adults who have had a lifetime of potential exposure. Method: Older adults (n = 200) completed the Trauma Health Questionnaire (THQ) and Personality Inventory for DSM-5 (PID-5). Results Multivariate analysis of covariance (MANCOVA) revealed significant differences in the five PID-5 domains across four levels of cumulative trauma exposure (Pillai’s Trace =.14, F(5, 519) =1.73, p =.04, ηp2=.05). Years since first traumatic event was not significant as a covariate (Pillai’s Trace =.02, F(4, 173) =0.80, p =.55, ηp2=.02). Significant group differences were found in the PID-5’s Psychoticism (F(3, 175) = 5.71, p < .001, ηp2 = .09) and Detachment (F(3, 175) = 2.91, p = .03, ηp2 = .05). According to Bonferroni post-hoc tests, the high trauma exposure group was significantly higher in Psychoticism than low trauma exposure, low to medium trauma exposure, and medium to high trauma exposure groups. For Detachment, the high trauma exposure group was significantly higher than the low trauma exposure and low to medium exposure groups. Discussion Findings suggest that cumulative trauma exposure is associated with specific pathological personality traits in older adults. High levels of trauma exposure may be particularly related to eccentric and detached traits that persist in later life, reflecting the need for clinical assessment in both domains.

The lability and liability of female ‘borderline’ sexuality: a feminist Foucauldian discourse analysis of Thompson et al’s (2017) ‘Sexuality and sexual health among female youth with borderline personality disorder pathology’

The purpose of this discourse study is to deconstruct how a journal article published in Early Intervention in Psychiatry, ‘Sexuality and sexual health among female youth with borderline personality disorder pathology’ (Thompson et al, 2017), constructs the sexuality of young women diagnosed with ‘borderline personality disorder’. The methodology used was Foucauldian discourse analysis, following Hook’s (2001) recommendation to re-situate a text within its socio-political location and among its material correlates, as well as analysing its intra-textual discursive features. The process of analysis involved repeated close readings of the text by Thompson et al (2017), with a focus on binary oppositions within the text, and the power/knowledge nexus in which it is situated. The analysis identified three key discourses at work in the text: the discourse of the academy, the discourse of dichotomy, and the discourse of ‘borderline’ sexuality, which contains a conceptually unstable paradox concerning female ‘borderline’ sexual agency. The consequences of these findings, their historical context, and implications for practice and classification are discussed.

A Preliminary Study of the Interactive Effect of Avoidant Personality Disorder Symptoms and Expressive Suppression on the Outcome of a Psychodynamically Oriented Day Treatment Program.

Introduction: Patients with avoidant personality disorder (AvPD) pathology tend to have poor prognosis in psychotherapy, yet there has been little research conducted to better understand why their outcomes are limited, making it difficult to improve treatments for them. Expressive suppression is a dysfunctional emotion regulation strategy that may exacerbate avoidant tendencies, further complicating the therapeutic process. Methods: Using data from a naturalistic study (N = 34) of a group-based day treatment program, we examined whether there was an interactive effect of AvPD symptoms and expressive suppression on treatment outcome. Results: Findings revealed a significant moderating effect of expressive suppression on the association between AvPD symptoms and treatment outcome. The outcome for patients with more severe AvPD symptoms was particularly poor when they engaged in high levels of expressive suppression. Discussion: The findings suggest that the combination of significant AvPD pathology and high expressive suppression is associated with poorer responsiveness to treatment.

Object constancy in adolescents with borderline personality disorder pathology.

Persistent, interpersonal difficulties are a core feature of borderline personality disorder (BPD). Theories propose that these may result from an insufficient object constancy, for example, the insufficient capacity to maintain feelings of closeness (FC) toward a person when he or she is absent. Based on this assumption, this study examined whether FC toward the mother or the best friend were more dependent on previous contact in adolescents with BPD pathology compared with healthy controls. In addition, the influence of different contact modes was explored. N = 52 female adolescents aged 14 to 18 years (n = 24 with ≥ 5 BPD symptoms [full-threshold BPD], n = 10 with 1-4 BPD symptoms [subthreshold BPD], n = 18 healthy controls) completed up to 12 e-diaries a day on 2 consecutive weekends. Using multilevel mixed-effect regression analyses, we found that the more BPD symptoms a patient fulfilled, the more dependent were FC toward the best friend on actual contact. In contrast, BPD pathology did not influence the dependency of the FC toward the mother on actual contact. Finally, the mode of contact seems to matter: The more BPD symptoms a patient met, the more was the FC toward the best friend dependent on personal compared with written or no contact, whereas phone or written contact was no different from no contact. The present findings partially support the theory of an insufficient object constancy in BPD that seems to become apparent in adolescence mainly in relationships with peers. Replication of the findings, particularly with regard to the impact of mode of contact, in larger samples is required. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Associations between physical health and the alternative model of personality disorders: A cross-sectional age study.

The Alternative Model of Personality Disorders (AMPD) is a relatively new dimensional model of personality disorders (PDs) that assesses two diagnostic constructs: personality functioning and pathological personality traits. Thus far, research on the AMPD among older adults has been limited, but the research that does exist suggests limited generalizability to the unique biopsychosocial context of later life. To further examine the applicability of the AMPD to older adults, the purpose of this study was to examine relationships between the AMPD's two constructs with perceived physical health status among younger and older adult samples. Older adults (n = 222) and younger adults (n = 215) completed the Short Form-36 (SF-36), Levels of Personality Functioning Scale-Self-Report (LPFS-SR), and Personality Inventory for DSM-5-Brief Form (PID-5-BF). Correlations and Fisher's z-tests revealed significantly stronger relationships between the SF-36 with the LPFS-SR and PID-5-BF domains for older adults than younger adults. Additionally, age group significantly moderated the relationships between personality functioning and pathological personality traits and health. The stronger relationships between health and the AMPD's constructs for older adults suggest meaningful overlap between negative health outcomes and PD pathology. Future research should further investigate specific mechanisms in which personality pathology negatively impacts health in older adults.

Fear of compassion from others explains the relation between borderline personality disorder symptoms and ineffective conflict resolution strategies among patients with substance use disorders

BackgroundBorderline personality disorder (BPD) pathology is common among patients with substance use disorders (SUDs) and associated with a variety of negative outcomes, including worse SUD outcomes. One particularly relevant outcome with links to substance use problems that is likely to be elevated among SUD patients with BPD symptoms is ineffective conflict resolution strategies in romantic relationships. However, no research to date has examined the relation of BPD pathology to strategies for managing conflict in romantic relationships among patients with SUDs, or the factors that may increase the use of ineffective strategies within this population. Thus, this study examined the relations of BPD symptoms to ineffective responses to romantic relationship conflict surrounding substance use among residential patients with SUDs, as well as the explanatory roles of fear of compassion from and for others in these relations.MethodsPatients in a community-based correctional SUD residential treatment facility (N = 93) completed questionnaires, including a measure of BPD symptoms, fear of compassion from and for others, and strategies for responding to conflict surrounding substance use in romantic relationships.ResultsFear of compassion from others accounted for significant variance in the relations of BPD symptoms to the ineffective conflict resolution strategies of reactivity, domination, and submission, whereas fear of compassion for others only accounted for significant variance in the relation between BPD symptoms and the strategy of separation (which is not always ineffective).ConclusionsTogether, findings suggest that it is fear of compassion from others (vs. fear of compassion for others) that explains the relation between BPD symptoms and ineffective responses to romantic relationship conflict surrounding substance use among SUD patients. Findings highlight the potential utility of interventions aimed at reducing fears of compassion and increasing comfort with and tolerance of compassion from both others and oneself among SUD patients with BPD symptoms in order to strengthen relationships and reduce risk for relapse.

The Contribution of Transference Focused Psychotherapy in Improving Psychiatry Trainees’ Attitude and Technical Confidence Towards Patients With Personality Disorders

AimsTransference-focused psychotherapy (TFP) is a manualized evidence-based treatment for severe personality disorders (PDs) based on a psychodynamic approach that focuses on object relations theory. It has been used as a teaching tool in different psychiatric settings. Psychiatry trainees are often the “first-responders” in multiple services, and they have to deal with patients with PDs in various settings. Yet there is a documented gap in psychiatry trainees’ education regarding the assessment and management of patients with PD pathology. The aim of our study was to evaluate whether a series of teaching sessions on TFP theory and techniques as applied to PD could improve the attitude and technical confidence of psychiatric trainees in the clinical encounter of a patient with a PD.MethodsTwo cohorts of psychiatry trainees in Tower Hamlet's East London Foundation Trust received four teaching sessions, each of one hour duration, on TFP theory and techniques. All the sessions were delivered online, using video teleconferencing software. 14 Trainees completed 2 questionnaires, pre- and post-teaching: the Attitude to Personality Disorder Questionnaire (APDQ) and the Clinical Confidence with Personality Disorder Questionnaire (CCPDQ). The APDQ asks the responder to score from 1–6 the frequency they experience certain feelings towards patients with PD. In the absence of a suitable instrument, we developed the CCPDQ consisting of a set of 13 questions rated on a 6-point Likert scale addressing key issues identified in TFP including establishing and maintaining the treatment frame and in implementing the 4 main techniques. We also conducted a 1-hour focus group post teaching which was videorecorded, transcribed, and analysed thematically.ResultsOn quantitative analysis, the Wilcoxon signed-rank test indicated statistically significant improvements in the total APDQ score (P = 0.003, r = 0.81) and in the CCPDQ questionnaires (P = 0.001, r = 0.88).The thematic analysis showed an overall positive effect of the TFP teaching on trainees’ attitude and confidence: they felt it improved their understanding of the nature of personality disorder, their awareness and management of countertransference, awareness of object relations and relation dyads at play in the encounter.ConclusionTraining junior doctors about TFP theory and techniques as applied to PD can significantly improve their attitude towards these patients and their technical confidence in the clinical encounter. Of note, our workshop is resource light and can easily be delivered by remote teaching. Based on these findings, teaching of TFP in the core psychiatric training curriculum should be considered.

Alliance rupture profiles by personality disorder pathology in psychotherapy for depression: Tendencies, development, and timing.

Clinical and theoretical considerations presume that patients with different personality disorder (PD) clusters will be associated with distinct alliance rupture profiles; however, there is scarce empirical literature examining this. The present study adopted a systematic framework for investigating profiles of alliance ruptures for individuals belonging to each of the three PD clusters. The sample consisted of 94 patients from a randomized controlled trial for treatment of depression. PD cluster features were assessed at intake and ruptures were assessed across treatment. Three sets of multilevel analyses were conducted to test differences between the PD clusters in the general tendency to show a rupture profile, rupture development throughout the treatment, and timing of predicting ruptures by PD within sessions. The three clusters were associated with distinct profiles of alliance ruptures. Clusters A and B were characterized by a general tendency to show more withdrawal and confrontation ruptures. Cluster A had a greater decrease in confrontation ruptures over the course of treatment, while cluster B had a greater decrease in withdrawal ruptures. Cluster C was characterized by a general tendency to show fewer withdrawal and confrontation ruptures, with a greater increase in both ruptures over the course of treatment. For withdrawal ruptures, the differences between clusters were evident from the beginning of sessions, whereas for confrontation ruptures, there was less of a difference between beginning and end of sessions. The distinct profiles of alliance ruptures for each PD cluster may contribute to progress towards tailoring treatment to individuals with PDs.

Narcissistic Personality Disorder: Are Psychodynamic Theories and the Alternative DSM-5 Model for Personality Disorders Finally Going to Meet?

Narcissistic Personality Disorder is the new borderline personality disorder of our current era. There have been recent developments on narcissism that are certainly worthwhile examining. Firstly, relational and intersubjective psychoanalysts have been rethinking the underlying concepts of narcissism, focusing on the development of self and relations to others. Secondly, in the DSM-5, the Alternative DSM-5 Model for Personality Disorders (AMPD) was presented for a dimensional evaluation of the severity of personality disorder pathology. The combined dimensional and trait conceptualization of NPD opened the door to new integrated diagnostic perspectives, including both internal and interpersonal functioning. Finally, Pincus and Lukowitsky encourage clinicians to use a hierarchical model of pathological narcissism, as it opens up opportunities for shared points of interest in empirical research from different scholarly perspectives. As for most non-psychodynamic clinicians and researchers the DSM-5 clearly bears dominant weight in their work, we will take the AMPD model for NPD as our point of reference. We will discuss the narcissist's unique pattern of self-impairments in identity and self-direction, and of interpersonal disfunctioning (evaluated by assessing empathy and intimacy). Subsequently, we will examine how contemporary psychodynamic theories and the hierarchical model of Pincus and Lukowitsky additionally inform or contradict the AMPD. For us, one of the big advantages of the AMPD is the use of structured clinical evaluations of disturbances of the self and interpersonal functioning and the dimensional evaluation of severity. As psychodynamically oriented therapists, we are enthusiastic about the opportunities for inclusion of psychodynamic concepts, but we also discuss a number of sticking points.

Specialist teams as constituted are unsatisfactory for treating people with personality disorders.

It is now becoming standard practice in most advanced economies to provide specialist services for those with personality disorder. Such services, almost exclusively, provide complex well-structured psychological interventions lasting many months for a small number of those with borderline personality disorder pathology. The evidence suggests that these treatments are effective but they can only be provided for a small number of people. However, in every area the numbers of patients with significant personality disorder far exceeds those that are treated, and most of these have other personality disorders. It is argued that the current service system is not working efficiently and should be replaced by one that provides resources and expertise within community teams with some external advice from specialists but no transfer of responsibility to a designated team.

Applied Transference-Focused Psychotherapy: An Overview and Update.

Transference-focused psychotherapy (TFP), developed and studied as an extended individual psychotherapy for patients with borderline personality disorder (BPD), rests on a rich theoretical foundation informed by psychoanalytic object relations theory. "Applied TFP" is a developing initiative using TFP principles in multiple clinical situations other than the standard extended individual psychotherapy, which has been empirically validated and is detailed in the TFP treatment manual. The growing application of TFP principles in innovative, overlapping ways has been focused primarily in three spheres: (1) the integration of TFP principles in pluralistic theoretical approaches to treatment of patients with personality disorder pathology; (2) the use of TFP elements in multiple teaching situations as part of curricula for trainees and practicing clinicians, and (3) the employment of TFP theory and interventions in settings across a continuum of patient acuity, tailored for patients with varying diagnoses. The use of TFP principles in the situations described directly addresses needs emerging in particular contexts that reflect specific requirements of clinician practice and training and of broader public health missions.

Money Questions and the Structural Interview.

Kernberg's structural interview integrates exploration of elements of personality organization into the standard initial psychiatric evaluation. The structural interview approach, while essential to transference-focused psychotherapy for patients with borderline personality disorder, is not limited to use in that context. Following the model of the structural interview, clinicians ask a series of questions, which elucidate elements of personality pathology, thereby facilitating comprehensive diagnosis, guiding treatment, and informing prognosis. Direct questioning about finances and the clinician's general curiosity about issues related to money, in the context of the structural interview, can be high-yield lines of inquiry. Patients' history with their finances, attitudes about money, and ways questions about finance emerge in the transference around fees and related concerns, can add an important, often overlooked, dimension to the assessment of personality organization and personality disorder pathology. This article proposes the utility of prioritizing questions regarding money, as might be integrated into the structural interview, as a template for a broader recognition of the value of this line of inquiry in a diagnostic assessment process.

Motives for opioid use explain the relation between borderline personality disorder pathology and opioid use problems

Despite the established relations between borderline personality disorder (BPD) and substance use problems in general, there is a dearth of research on the relation between BPD pathology and opioid use problems, as well as factors that may explain this relation. Therefore, this study examined the indirect relations of BPD pathology to opioid use problems (i.e., prescription opioid misuse, apprehension about prescription opioid use, and opioid cravings) through motives for opioid use (i.e., coping, enhancement, social, and conformity motives) among 68 patients endorsing prescription opioid misuse in a residential correctional substance use disorder (SUD) treatment facility. Participants completed measures of BPD pathology, motives for opioid use, and opioid use problems. Findings revealed significant indirect relations of BPD pathology to opioid misuse through coping and enhancement motives, apprehension about opioid use through coping, enhancement, and social motives, and opioid cravings through coping motives within this SUD sample. Results illustrate the relevance of both emotion- and interpersonal-related motives for opioid use to opioid use problems among patients with BPD pathology in SUD treatment.

Predicting engagement in nonsuicidal self-injury (NSSI) over the course of 12 months: the roles of borderline personality disorder pathology and emotional consequences of NSSI

Background: Despite theories that negative reinforcement in the form of relief from negative emotions maintains nonsuicidal self-injury (NSSI), no studies have examined the extent to which specific emotional consequences of NSSI predict the maintenance of NSSI over time or explain the greater risk for NSSI found among individuals with borderline personality disorder (BPD) pathology. This study examined whether specific emotional consequences of NSSI relate to the continuance of NSSI behavior over a 12-month period and explain the relation of baseline BPD pathology to future NSSI. Methods: Participants with a history of recent repeated NSSI (N = 84) completed baseline measures of BPD pathology, NSSI, and the emotional antecedents and consequences of NSSI, including self-conscious emotions, undifferentiated negative affect, anger, emptiness, sadness, and anxiety; follow-up data on NSSI were collected every three months for one year. Results: Of the emotional consequences of NSSI examined here, only self-conscious emotions significantly predicted the presence and frequency of NSSI during the 12-month follow-up period. Likewise, whereas BPD pathology was not directly associated with later NSSI, both overall BPD pathology and the specific BPD feature of identity problems were indirectly related to the presence of 12-month NSSI through the greater frequency of post-NSSI self-conscious emotions. Limitations: Emotional consequences of NSSI were assessed using a retrospective self-report measure. Only frequency, and not intensity, of emotions before and after NSSI were assessed. Conclusions: Results suggest a distinct role of post-NSSI self-conscious emotions in the maintenance of NSSI among individuals with and without BPD pathology.

Early maladaptive schemas and their relation to personality disorders: A correlational examination in a clinical population.

Personality disorder (PD) pathology has been linked to early maladaptive schemas (EMSs). Because of a large heterogeneity in study populations, sample size, statistical analyses and conceptualizations in the literature, the exact relationships between PDs and EMSs are still unclear. The current study examined the relationship between borderline, dependent, avoidant and obsessive–compulsive PDs, represented dimensionally as number of traits, and 15 different EMSs as measured by the Young Schema Questionnaire (YSQ). A total of N = 130 inpatients took part in the study (M age = 43.6, gender = 51.5% female). Stepwise regressions indicated that borderline, dependent, avoidant and obsessive–compulsive PD traits were partly characterized by specific EMSs and EMSs grouped as domains (i.e., other‐directedness domain for dependent PD and overvigilance for obsessive–compulsive PD) and that relations with a variety of domains and EMSs were overlapping for the PD dimensions (i.e., disconnection and rejection for both borderline and avoidant PDs). This suggests that PDs are reflected by a hybrid model of EMSs, with some EMSs and domains that relate to a broader vulnerability factor for PDs, and other domains that differentially relate to the independent PDs. Findings are informative for clinicians, as various EMSs per PD may be targeted in therapy.

Implications of a Four Dimensional Adult Attachment Style Model on Personality Disorder Pathology

Personality disorders (PD) are characterized by impairments in social functioning. Attachment styles are critical for social functioning and consist in relational patterns across relationships. The present study explores the prevalence of each of the four categories of adult attachment (i.e. secure, fearful, preoccupied, and dismissing) in a sample of personality disorders compared to healthy controls.

Borderline personality disorder traits associate with midlife cardiometabolic risk.

There is growing interest in relationships between borderline personality disorder (BPD) pathology and physical health outcomes. Diagnostic BPD and BPD-related traits, for instance, have been shown to associate with self-reported cardiovascular disease and various cardiometabolic risk factors. However, potential confounding of these associations by comorbid depression, which itself contributes to risk for heart disease, remains unresolved, and previous research is limited by nearly uniform reliance on self-reported health status. In the present study, we examine the association of BPD traits and contemporaneously assessed depressive mood with instrumented measures of cardiometabolic risk in a midlife community sample (N = 1,295). BPD pathology was measured using dimensional, multi-informant trait measures; depressive symptomology was self-reported; and cardiometabolic risk was indexed via multiple indicators of insulin resistance, adiposity, dyslipidemia, and blood pressure. Structural equation modeling was used to estimate the effects of BPD traits and depressive symptoms on aggregated cardiometabolic risk, adjusting for their shared variance. Results showed both BPD features and depressive symptomatology related to the extent of cardiometabolic risk; when examined simultaneously, only BPD associated independently with risk indicators. In further supporting a link between BPD pathology and cardiovascular disease risk, these findings warrant future work to elucidate intervening behavioral and biological mechanisms. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Augmenting Psychiatric Risk Management: Practical Applications of Transference- Focused Psychotherapy (TFP) Principles

Risk management challenges in psychiatry are made more complicated when they involve the treatment of patients with primary or co-occurring personality disorder pathology. Principles of transference-focused psychotherapy (TFP), a treatment empirically validated for borderline personality disorder (BPD) and with utility for patients with varying personality disorder presentations, are practical, commonsense measures that can guide clinicians in these difficult matters. Applied TFP principles are useful in this area even when clinicians are not engaged in an extended individual psychotherapy. Central to the TFP approach are: (1) an openness to identifying personality disorder pathology; (2) a deliberate process to assess personality disorder diagnoses with attention to severity of illness; (3) an emphasis on the informed consent process, which includes sharing fully with the patient the clinician's diagnostic impression with germane psychoeducation; (4) an expectation for timely contacts at the outset of treatment with prior practitioners and with family members, when indicated; and (5) the development and maintenance of a treatment frame. TFP stresses the active monitoring of three channels of communication (what the patient says, how the patient behaves, and the clinician's countertransference) as a guiding precept that informs clinical decision-making. TFP principles can serve as a useful risk management "checklist" by organizing a clinician's approach to inherently confounding material.