We provide a basic review of the data screening and assumption testing issues relevant to exploratory and confirmatory factor analysis along with practical advice for conducting analyses that are sensitive to these concerns. Historically, factor analysis was developed for explaining the relationships among many continuous test scores, which led to the expression of the common factor model as a multivariate linear regression model with observed, continuous variables serving as dependent variables, and unobserved factors as the independent, explanatory variables. Thus, we begin our paper with a review of the assumptions for the common factor model and data screening issues as they pertain to the factor analysis of continuous observed variables. In particular, we describe how principles from regression diagnostics also apply to factor analysis. Next, because modern applications of factor analysis frequently involve the analysis of the individual items from a single test or questionnaire, an important focus of this paper is the factor analysis of items. Although the traditional linear factor model is well-suited to the analysis of continuously distributed variables, commonly used item types, including Likert-type items, almost always produce dichotomous or ordered categorical variables. We describe how relationships among such items are often not well described by product-moment correlations, which has clear ramifications for the traditional linear factor analysis. An alternative, non-linear factor analysis using polychoric correlations has become more readily available to applied researchers and thus more popular. Consequently, we also review the assumptions and data-screening issues involved in this method. Throughout the paper, we demonstrate these procedures using an historic data set of nine cognitive ability variables.

Treatment dropout among individuals with borderline personality disorder (BPD) is associated with negative psychosocial outcomes. Identifying predictors of dropout among this population is critical to understanding how to improve treatment retention. The present study extends the current literature by examining both static and dynamic predictors of dropout. Chronically suicidal outpatients diagnosed with BPD (N = 42) were randomly assigned to a 20-week dialectical behavior therapy (DBT) skills training group. Static and dynamic predictors were assessed at baseline, 5, 10, 15, 20 weeks, and 3 months post-intervention. A post-hoc two-stage logistic regression analysis was conducted to predict dropout propensity. Receiving disability benefits at baseline and decreases in mindfulness were associated with significantly increased probability of dropout. Clinicians working with chronically self-harming outpatients diagnosed with BPD would benefit from prioritizing clinical interventions that enhance mindfulness in order to decrease dropout propensity.

Despite research supporting the effectiveness of dialectical behavior therapy (DBT) for borderline personality disorder (BPD), few studies have examined how DBT leads to clinical change. DBT is theorized to lead to improved clinical outcomes by enhancing the capacity for emotion regulation, including improvement in skills (e.g., mindfulness and distress tolerance) for managing emotional distress and impulsive behaviors. Therefore, the aim of this study was to test whether improvements in mindfulness and distress tolerance indirectly affect the relationship between DBT skills training and clinical outcomes. The sample consists of 84 patients diagnosed with BPD who were enrolled in a randomized controlled trial comparing 20 weeks of DBT-skills group (DBT-S) to an active waitlist control. Mindfulness and distress tolerance were assessed at baseline and at the end of the 20 weeks. BPD symptoms, general psychiatric symptoms, and social adjustment were assessed at the end of 20 weeks and combined into a latent variable representing a broad assessment of general psychopathology. Relative to the waitlist control group, improvements in mindfulness and distress tolerance each independently indirectly affected the relationship between DBT-S and posttreatment general psychopathology. Findings suggest that DBT-S exerts its effects on outcomes through improvements in mindfulness and distress tolerance. These findings support the significance of mindfulness and distress tolerance in DBT-S for BPD. Limitations, future directions, and clinical implications are discussed.

<b><i>Introduction:</i></b> Evidence-based psychotherapies for borderline personality disorder (BPD) are lengthy, posing a barrier to their access. Brief psychotherapy may achieve comparable outcomes to long-term psychotherapy for BPD. Evidence is needed regarding the comparative effectiveness of short- versus long-term psychotherapy for BPD. <b><i>Objective:</i></b> The aim was to determine if 6 months of Dialectical Behavior Therapy (DBT) is noninferior to 12 months of DBT in terms of clinical effectiveness. <b><i>Methods:</i></b> This two-arm, single-blinded, randomized controlled noninferiority trial with suicidal or self-harming patients with BPD was conducted at two sites in Canada. Participants (<i>N</i> = 240, <i>M</i> (SD)_age = 28.27 (8.62), 79% females) were randomized to receive either 6 (DBT-6) or 12 months (DBT-12) of comprehensive DBT. Masked assessors obtained measures of clinical effectiveness at baseline and every 3 months, ending at month 24. DBT-6 and DBT-12 were outpatient treatments consisting of weekly individual therapy sessions, weekly DBT skills training group sessions, telephone consultation as needed, and weekly therapist consultation team meetings. <b><i>Results:</i></b> The noninferiority hypothesis was supported for the primary outcome, total self-harm (6 months: margin = −1.94, <i>M</i>_diff [95% CI] = 0.16 [−0.14, 0.46]; 12 months: margin = −1.47, <i>M</i>_diff [95% CI] = 0.04 [−0.17, 0.23]; 24 months: margin = −1.25, <i>M</i>_diff [95% CI] = 0.12 [−0.02, 0.36]). Results also supported noninferiority of DBT-6 for general psychopathology and coping skills at 24 months. Furthermore, DBT-6 participants showed more rapid reductions in BPD symptoms and general psychopathology. There were no between-group differences in dropout rates. <b><i>Conclusions:</i></b> The noninferiority of a briefer yet comprehensive treatment for BPD has potential to reduce barriers to treatment access.

Randomized pretest, posttest, follow-up (RPPF) designs are often used for evaluating the effectiveness of an intervention. These designs typically address two primary research questions: (1) Do the treatment and control groups differ in the amount of change from pretest to posttest? and (2) Do the treatment and control groups differ in the amount of change from posttest to follow-up? This study presents a model for answering these questions and compares it to recently proposed models for analyzing RPPF designs due to Mun, von Eye, and White (2009) using Monte Carlo simulation. The proposed model provides increased power over previous models for evaluating group differences in RPPF designs.