David M. Erceg-Hurn

Drugs, Money, and Graphic Ads: A Critical Review of the Montana Meth Project

The Montana Meth Project (MMP) is an organization that launched a large-scale methamphetamine prevention program in Montana in 2005. The central component of the program is a graphic advertising campaign that portrays methamphetamine users as unhygienic, dangerous, untrustworthy, and exploitive. Montana teenagers are exposed to the advertisements three to five times a week. The MMP, media and politicians have portrayed the advertising campaign as a resounding success that has dramatically increased anti-methamphetamine attitudes and reduced drug use in Montana. The program is currently being rolled out across the nation, and is receiving considerable public funding. This article critically reviews the evidence used by the MMP to claim that its advertising campaign is effective. The main finding is that empirical support for the campaign is weak. Claims that the campaign is effective are not supported by data. The campaign has been associated with increases in the acceptability of using methamphetamine and decreases in the perceived danger of using drugs. These and other negative findings have been ignored and misrepresented by the MMP. There is no evidence that reductions in methamphetamine use in Montana are caused by the advertising campaign. On the basis of current evidence, continued public funding and rollout of Montana-style methamphetamine programs is inadvisable.

Comparing two independent groups via the lower and upper quantiles

The most common strategy for comparing two independent groups is in terms of some measure of location intended to reflect the typical observation. However, it can be informative and important to compare the lower and upper quantiles as well, but when there are tied values, extant techniques suffer from practical concerns reviewed in the paper. For the special case where the goal is to compare the medians, a slight generalization of the percentile bootstrap method performs well in terms of controlling Type I errors when there are tied values [Wilcox RR. Comparing medians. Comput. Statist. Data Anal. 2006;51:1934–1943]. But our results indicate that when the goal is to compare the quartiles, or quantiles close to zero or one, this approach is highly unsatisfactory when the quantiles are estimated using a single order statistic or a weighted average of two order statistics. The main result in this paper is that when using the Harrell–Davis estimator, which uses all of the order statistics to estimate a quantile, control over the Type I error probability can be achieved in simulations, even when there are tied values, provided the sample sizes are not too small. It is demonstrated that this method can also have substantially higher power than the distribution free method derived by Doksum and Sievers [Plotting with confidence: graphical comparisons of two populations. Biometrika 1976;63:421–434]. Data from two studies are used to illustrate the practical advantages of the method studied here.

Therapeutic alliance in Enhanced Cognitive Behavioural Therapy for bulimia nervosa: probably necessary but definitely insufficient.

The present paper assessed therapeutic alliance over the course of Enhanced Cognitive Behavioural Therapy (CBT-E) in a community-based sample of 112 patients with a diagnosis of bulimia nervosa (BN) or atypical BN. Temporal assessment of alliance was conducted at three time points (the start, middle and end of treatment) and the relationship between alliance and treatment retention and outcome was explored. Results indicated that the alliance between patient and therapist was strong at all stages of CBT-E, and even improved in the early stages of treatment when behaviour change was initiated (weekly in-session weighing, establishing regular eating, and ceasing binge-eating and compensatory behaviours). The present study found no evidence that alliance was related to treatment retention or outcomes, or that symptom severity or problematic interpersonal styles interacted with alliance to influence outcomes. Alliance was also unrelated to baseline emotional or interpersonal difficulties. The study provides no evidence that alliance has clinical utility for the prediction of treatment retention or outcome in CBT-E for BN, even for individuals with severe symptoms or problematic interpersonal styles. Early symptom change was the best predictor of outcome in CBT-E. Further research is needed to determine whether these results are generalizable to patients with anorexia nervosa.

Group metacognitive therapy for repetitive negative thinking in primary and non-primary generalized anxiety disorder: An effectiveness trial

BACKGROUND Generalized anxiety disorder (GAD) is a common and highly comorbid anxiety disorder characterized by repetitive negative thinking (RNT). Treatment trials tend to exclude individuals with non-primary GAD, despite this being a common presentation in real world clinics. RNT is also associated with multiple emotional disorders, suggesting that it should be targeted regardless of the primary disorder. This study evaluated the acceptability and effectiveness of brief group metacognitive therapy (MCT) for primary or non-primary GAD within a community clinic. METHODS Patients referred to a specialist community clinic attended six, two-hour weekly sessions plus a one-month follow-up (N=52). Measures of metacognitive beliefs, RNT, symptoms, positive and negative affect, and quality of life were completed at the first, last, and follow-up sessions. RESULTS Attrition was low and large intent-to-treat effects were observed on most outcomes, particularly for negative metacognitive beliefs and RNT. Treatment gains increased further to follow-up. Benchmarking comparisons demonstrated that outcomes compared favorably to longer disorder-specific protocols for primary GAD. LIMITATIONS No control group or independent assessment of protocol adherence. CONCLUSIONS Brief metacognitive therapy is an acceptable and powerful treatment for patients with primary or non-primary GAD.

Comparing two dependent groups via quantiles

This paper considers two general ways dependent groups might be compared based on quantiles. The first compares the quantiles of the marginal distributions. The second focuses on the lower and upper quantiles of the usual difference scores. Methods for comparing quantiles have been derived that typically assume that sampling is from a continuous distribution. There are exceptions, but generally, when sampling from a discrete distribution where tied values are likely, extant methods can perform poorly, even with a large sample size. One reason is that extant methods for estimating the standard error can perform poorly. Another is that quantile estimators based on a single-order statistic, or a weighted average of two-order statistics, are not necessarily asymptotically normal. Our main result is that when using the Harrell–Davis estimator, good control over the Type I error probability can be achieved in simulations via a standard percentile bootstrap method, even when there are tied values, provided the sample sizes are not too small. In addition, the two methods considered here can have substantially higher power than alternative procedures. Using real data, we illustrate how quantile comparisons can be used to gain a deeper understanding of how groups differ.

Mechanisms of change during group metacognitive therapy for repetitive negative thinking in primary and non-primary generalized anxiety disorder.

Repetitive negative thinking (RNT) is a transdiagnostic process that serves to maintain emotional disorders. Metacognitive theory suggests that positive and negative metacognitive beliefs guide the selection of RNT as a coping strategy which, in turn, increases psychological distress. The aim of this study was to test the indirect effect of metacognitive beliefs on psychological distress via RNT. Patients (N=52) with primary and non-primary generalized anxiety disorder attended a brief, six-week group metacognitive therapy program and completed measures of metacognitive beliefs, RNT, and symptoms at the first and final treatment sessions, and at a one-month follow-up. Prospective indirect effects models found that negative metacognitive beliefs (but not positive metacognitive beliefs) had a significant indirect effect on psychological distress via RNT. As predicted by metacognitive theory, targeting negative metacognitions in treatment appears to reduce RNT and, in turn, emotional distress. Further research using alternative measures at multiple time points during therapy is required to determine whether the absence of a relationship with positive metacognitive beliefs in this study was a consequence of (a) psychometric issues, (b) these beliefs only being relevant to a subgroup of patients, or (c) a lack of awareness early in treatment.

Therapist adherence in the strong without anorexia nervosa (SWAN) study: A randomized controlled trial of three treatments for adults with anorexia nervosa.

Objective To develop a psychotherapy rating scale to measure therapist adherence in the Strong Without Anorexia Nervosa (SWAN) study, a multi-center randomized controlled trial comparing three different psychological treatments for adults with anorexia nervosa. The three treatments under investigation were Enhanced Cognitive Behavioural Therapy (CBT-E), the Maudsley Anorexia Nervosa Treatment for Adults (MANTRA), and Specialist Supportive Clinical Management (SSCM). Method The SWAN Psychotherapy Rating Scale (SWAN-PRS) was developed, after consultation with the developers of the treatments, and refined. Using the SWAN-PRS, two independent raters initially rated 48 audiotapes of treatment sessions to yield inter-rater reliability data. One rater proceeded to rate a total of 98 audiotapes from 64 trial participants. Results The SWAN-PRS demonstrated sound psychometric properties, and was considered a reliable measure of therapist adherence. The three treatments were highly distinguishable by independent raters, with therapists demonstrating significantly more behaviors consistent with the actual allocated treatment compared to the other two treatment modalities. There were no significant site differences in therapist adherence observed. Discussion The findings provide support for the internal validity of the SWAN study. The SWAN-PRS was deemed suitable for use in other trials involving CBT-E, MANTRA, or SSCM.

Assessing the efficacy of imagery-enhanced cognitive behavioral group therapy for social anxiety disorder: Study protocol for a randomized controlled trial

Cognitive behavior group therapy (CBGT) is effective for social anxiety disorder (SAD), but a substantial proportion of patients do not typically achieve normative functioning. Cognitive behavioral models of SAD emphasize negative self-imagery as an important maintaining factor, and evidence suggests that imagery is a powerful cognitive mode for facilitating affective change. This study will compare two group CBGT interventions, one that predominantly uses verbally-based strategies (VB-CBGT) and another that predominantly uses imagery-enhanced strategies (IE-CBGT), in terms of (a) efficacy, (b) mechanisms of change, and (c) cost-effectiveness. This study is a parallel groups (two-arm) single-blind randomized controlled trial. A minimum of 96 patients with SAD will be recruited within a public outpatient community mental health clinic in Perth, Australia. The primary outcomes will be self-reported symptom severity, caseness (SAD present: yes/no) based on a structured diagnostic interview, and clinician-rated severity and life impact. Secondary outcomes and mechanism measures include blind observer-rated use of safety behaviors, physiological activity (heart rate variability and skin conductance level) during a standardized speech task, negative self-beliefs, imagery suppression, fear of negative and positive evaluation, repetitive negative thinking, anxiety, depression, self-consciousness, use of safety behaviors, and the EQ-5D-5L and TiC-P for the health economic analysis. Homework completion, group cohesion, and working alliance will also be monitored. The outcomes of this trial will inform clinicians as to whether integrating imagery-based strategies in cognitive behavior therapy for SAD is likely to improve outcomes. Common and distinct mechanisms of change might be identified, along with relative cost-effectiveness of each intervention.

Bigger is better: Full-length versions of the Social Interaction Anxiety Scale and Social Phobia Scale outperform short forms at assessing treatment outcome.

The Social Interaction Anxiety Scale (SIAS) and Social Phobia Scale (SPS) are 20-item companion measures of social anxiety symptoms frequently used to evaluate outcome in treatment trials. The SIAS-6, SPS-6, and Social Interaction Phobia Scale (SIPS) are promising short forms of the SIAS and SPS. The current study evaluated whether it is sound to use these short scales instead of the full-length instruments to measure outcome in social anxiety disorder (SAD) treatment studies, using data from a trial in which 255 adults with SAD were treated with traditional or imagery-enhanced group cognitive–behavioral therapy. Several deficiencies with the short forms were identified including ceiling effects, inflated variances, imprecise effect size estimates, and a loss of statistical power when testing for between-treatment differences. Using the short forms can alter the substantive findings of a treatment trial, as genuine differences in efficacy between treatments can be missed. We recommend treatment outcome be measured using the full SIAS and SPS rather than the SIPS, SIAS-6, and SPS-6. The full-length instruments provide precise estimates of treatment effects and maximize the chance of detecting between-treatment differences when they exist.

Severe and enduring anorexia nervosa? Illness severity and duration are unrelated to outcomes from enhanced cognitive behaviour therapy

Objective: The present study aimed to examine whether Anorexia Nervosa (AN) illness severity or duration is associated with retention or treatment response in outpatient, enhanced cognitive–behavioral therapy (CBT-E). Method: Patients with a confirmed AN diagnosis (N = 134) completed measures of eating disorder symptoms and quality of life, and had their BMI objectively measured before, during, and after treatment. We evaluated whether illness severity or duration predicted treatment outcomes, using longitudinal regression models. Results: Greater levels of illness severity and duration were not associated with poorer treatment outcomes. Conclusions: Patients with more severe or long-standing AN illness did just as well in CBT-E as any other patient starting treatment. Therefore, classifying individuals as “severe and enduring” appears to lack clinical utility in CBT-E. Clinicians should continue to administer evidence-supported treatments such as CBT-E for patients with AN, regardless of duration or severity of AN illness.