Mark B. Powers

A Meta-Analytic Review of Psychosocial Interventions for Substance Use Disorders

OBJECTIVE Despite significant advances in psychosocial treatments for substance use disorders, the relative success of these approaches has not been well documented. In this meta-analysis, the authors provide effect sizes for various types of psychosocial treatments, as well as abstinence and treatment-retention rates for cannabis, cocaine, opiate, and polysubstance abuse and dependence treatment trials. METHOD With a comprehensive series of literature searches, the authors identified a total of 34 well-controlled treatment conditions-five for cannabis, nine for cocaine, seven for opiate, and 13 for polysubstance users-representing the treatment of 2,340 patients. Psychosocial treatments evaluated included contingency management, relapse prevention, general cognitive behavior therapy, and treatments combining cognitive behavior therapy and contingency management. RESULTS Overall, controlled trial data suggest that psychosocial treatments provide benefits reflecting a moderate effect size according to Cohens standards. These interventions were most efficacious for cannabis use and least efficacious for polysubstance use. The strongest effect was found for contingency management interventions. Approximately one-third of participants across all psychosocial treatments dropped out before treatment completion compared to 44.6% for the control conditions. CONCLUSIONS Effect sizes for psychosocial treatments for illicit drugs ranged from the low-moderate to high-moderate range, depending on the substance disorder and treatment under study. Given the long-term social, emotional, and cognitive impairments associated with substance use disorders, these effect sizes are noteworthy and comparable to those for other efficacious treatments in psychiatry.

Psychological approaches in the treatment of specific phobias: A meta-analysis ☆

Data from 33 randomized treatment studies were subjected to a meta-analysis to address questions surrounding the efficacy of psychological approaches in the treatment of specific phobia. As expected, exposure-based treatment produced large effects sizes relative to no treatment. They also outperformed placebo conditions and alternative active psychotherapeutic approaches. Treatments involving in vivo contact with the phobic target also outperformed alternative modes of exposure (e.g., imaginal exposure, virtual reality, etc.) at post-treatment but not at follow-up. Placebo treatments were significantly more effective than no treatment suggesting that specific phobia sufferers are moderately responsive to placebo interventions. Multi-session treatments marginally outperformed single-session treatments on domain-specific questionnaire measures of phobic dysfunction, and moderator analyses revealed that more sessions predicted more favorable outcomes. Contrary to expectation, effect sizes for the major comparisons of interest were not moderated by type of specific phobia. These findings provide the first quantitative summary evidence supporting the superiority of exposure-based treatments over alternative treatment approaches for those presenting with specific phobia. Recommendations for future research are also discussed.

Mechanism of Change in Cognitive-Behavioral Treatment of Panic Disorder: Evidence for the Fear of Fear Mediational Hypothesis.

Numerous clinical trials have demonstrated the efficacy of cognitive-behavioral treatment (CBT) for panic disorder. However, studies investigating the mechanisms responsible for improvement with CBT are lacking. The authors used regression analyses outlined by R. M. Baron and D. A. Kenny (1986) to test whether a reduction in fear of fear (FOF) underlies improvement resulting from CBT. Pre- and posttreatment measures were collected from 90 CBT-treated patients and 40 wait-list control participants. Overall, treatment accounted for 31% of the variance in symptom reduction. The potency of FOF as a mediator varied as a function of symptom facet, as full mediation was observed for the change in global disability, whereas the effects of CBT on agoraphobia, anxiety, and panic frequency were partially accounted for by reductions in FOF. Clinical implications and future research directions are discussed.

Disentangling the Effects of Safety-Behavior Utilization and Safety-Behavior Availability During Exposure-Based Treatment: A Placebo-Controlled Trial

The primary aim of the current study was to further investigate the deleterious effects of safety-seeking behaviors on fear reduction by disentangling the effects of perceived availability of threat-relevant safety behaviors during treatment versus their actual use. Participants (N=72) displaying marked claustrophobic fear were randomly assigned to 1 of 5 conditions: (a) exposure only (EO), (b) exposure with phobic safety-behavior availability (SBA), (c) exposure with safety-behavior utilization (SBU), (d) credible placebo treatment (PL), or (e) wait list (WL). High end-state functioning rates at posttreatment were as follows: EO = 94%, SBA = 45%, SBU = 44%, PL = 25%, and WL = 0%. Findings suggest that it is the perception of the availability of safety aids as opposed to their actual use that exerts a disruptive effect on fear reduction. Clinical implications are discussed.

A Phase I Study on the Feasibility and Acceptability of an Acupuncture/Hypnosis Intervention for Chronic Pediatric Pain

The purpose of the present study was to conduct a Phase I investigation examining the feasibility and acceptability of a complementary and alternative medicine (CAM) package combining acupuncture and hypnosis for chronic pediatric pain. Thirty-three sequentially referred children (21 girls) aged 6-18 years were offered 6 weekly sessions consisting of individually tailored acupuncture treatment together with a 20-minute hypnosis session (conducted while the needles were in place). Parent and child ratings of pain and pain-related interferences in functioning, as well as child ratings of anxiety and depression, were obtained at pre- and post-treatment. The treatment was highly acceptable (only 2 patients refused; > or = 90% completed treatment) and there were no adverse effects. Both parents and children reported significant improvements in childrens pain and interference following treatment. Childrens anticipatory anxiety declined significantly across treatment sessions. Our results support the feasibility and acceptability of a combined acupuncture/hypnosis intervention for chronic pediatric pain.

Yohimbine enhancement of exposure therapy for social anxiety disorder: A randomized controlled trial

BACKGROUND Preclinical and clinical trials suggest that yohimbine may augment extinction learning without significant side effects. However, previous clinical trials have only examined adults with specific phobias. Yohimbine has not yet been investigated in the augmentation of exposure therapy for other anxiety disorders. METHODS Adults (n = 40) with a DSM-IV diagnosis of social anxiety disorder were randomized to placebo or yohimbine HCl (10.8 mg) 1 hour before each of four exposure sessions. Outcome measures were collected at baseline, each treatment session, posttreatment, and 1-month follow-up. RESULTS Yohimbine was well tolerated. Yohimbine augmentation, relative to placebo augmentation, resulted in faster improvement and better outcomes on self-report measures of social anxiety disorder severity (Liebowitz Social Anxiety Scale, d = .53) and depressed mood severity (Beck Depression Inventory, d = .37) but not on the clinician-rated measures (Clinical Global Impressions-Severity Scale, d = .09; Clinical Global Impressions-Improvement Scale, d = .25). Between-group differences on the Liebowitz Social Anxiety Scale were moderated by the level of fear reported at the end of an exposure exercise (end fear), such that the advantage of yohimbine over placebo was only evident among patients who reported low end fear. CONCLUSIONS The results provide moderate support for yohimbine as a therapeutic augmentation strategy for exposure therapy in social anxiety disorder, one that may be especially effective when coupled with successful exposure experiences. Beneficial effects for yohimbine were readily evident for self-report measures but not for clinician-rated outcomes of social anxiety severity and improvement.

Exercise augmentation of exposure therapy for PTSD: Rationale and pilot efficacy data

Brain-derived neurotrophic factor (BDNF) is associated with synaptic plasticity, which is crucial for long-term learning and memory. Some studies suggest that people suffering from anxiety disorders show reduced BDNF relative to healthy controls. Lower BDNF is associated with impaired learning, cognitive deficits, and poor exposure-based treatment outcomes. A series of studies with rats showed that exercise elevates BDNF and enhances fear extinction. However, this strategy has not been tested in humans. In this pilot study, we randomized participants (N = 9, 8 females, MAge = 34) with posttraumatic stress disorder (PTSD) to (a) prolonged exposure alone (PE) or (b) prolonged exposure+exercise (PE+E). Participants randomized to the PE+E condition completed a 30-minute bout of moderate-intensity treadmill exercise (70% of age-predicted HRmax) prior to each PE session. Consistent with prediction, the PE+E group showed a greater improvement in PTSD symptoms (d = 2.65) and elevated BDNF (d = 1.08) relative to the PE only condition. This pilot study provides initial support for further investigation into exercise augmented exposure therapy.

Behavioral versus cognitive treatment of obsessive-compulsive disorder: an examination of outcome and mediators of change

OBJECTIVE To examine symptom change over time, the effect of attrition on treatment outcome, and the putative mediators of cognitive therapy (CT) versus behavior therapy (BT) for obsessive-compulsive disorder (OCD) using archival data. METHOD Sixty-two adults with OCD were randomized to 20 sessions of CT (N = 30) or BT (N = 32) that consisted of 4 weeks of intensive treatment (16 hr total) and 12 weeks of maintenance sessions (4 hr). Independent evaluators assessed OCD severity using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) at baseline and at Weeks 4, 16 (posttreatment), 26, and 52 (follow-up). Behavioral avoidance, depressive symptoms, and dysfunctional beliefs regarding responsibility were also measured at each assessment. Study hypotheses were tested using multilevel modeling. RESULTS The slope of change in Y-BOCS scores was significantly greater in BT than in CT (d = 0.69), and those receiving BT had lower Y-BOCS scores at the final assessment than those receiving CT (d = 1.17). The greater slope of change in BT versus CT did not differ for dropouts versus completers. Reduction in depressed mood mediated changes in Y-BOCS across the 2 treatments, but a reduction in sense of responsibility and a decrease in avoidance did not. Instead, Y-BOCS improvements appeared to precede a decrease in avoidance. CONCLUSIONS BT may have some therapeutic advantage over CT in the treatment of OCD, and this advantage does not appear to be due to a differential pattern of responding for treatment dropouts versus completers. Further, inconsistent with hypotheses, improvements in OCD symptoms were mediated by reductions in depressed mood instead of decreases in avoidance and responsibility. Theoretical, methodological, and clinical implications are discussed.

Does yohimbine hydrochloride facilitate fear extinction in virtual reality treatment of fear of flying? a randomized placebo-controlled trial

Background: Research suggests that yohimbine hydrochloride (YOH), a noradrenaline agonist, can facilitate fear extinction. It is thought that the mechanism of enhanced emotional memory is stimulated through elevated noradrenaline levels. This randomized placebo-controlled trial examined the potential exposure-enhancing effects of YOH in a clinical sample of participants meeting DSM-IV criteria for a specific phobia (fear of flying). Methods: Sixty-seven participants with fear of flying were randomized to 4 sessions of virtual reality exposure therapy (VRET) combined with YOH (10 mg), or 4 sessions of VRET combined with a placebo. Treatment consisted of 4 weekly 1-hour exposure sessions consisting of two 25-minute virtual flights. At pre- and post- treatment, fear of flying was assessed. The YOH or placebo capsules were administered 1 h prior to exposures. The manipulation of the noradrenaline activity was confirmed by salivary α-amylase (sAA) samples taken pre-, during and post-exposure. Results: Forty-eight participants completed treatment. Manipulation of noradrenaline levels with YOH was successful, with significantly higher levels of sAA in the YOH group when entering exposure. Results showed that both groups improved significantly from pre- to post-treatment with respect to anxiety reduction. However, although the manipulation of noradrenaline activity was successful, there was no evidence that YOH enhanced outcome. Conclusions: Participants improved significantly on anxiety measures independently of drug condition, after 4 sessions of VRET. These data do not support the initial findings of exposure-enhancing effects of YOH in this dosage in clinical populations.

Emotional responding to hyperventilation as a predictor of agoraphobia status among individuals suffering from panic disorder

Some data suggest that panic patients with extensive agoraphobia (PDA) display more intense respiratory distress during their panic attacks than Panic disorder (PD) patients. However, no studies have determined if PDA patients also show heightened sensitivity to a respiratory challenge compared to PD patients. The current study examined the differential emotional responding to hyperventilation among PDA patients, PD patients, and a non-clinical group with a history of panic attacks. Response to hyperventilation challenge did not distinguish non-clinical panickers from panic patients; however, behavioral tolerance to hyperventilation challenge significantly predicted agoraphobia status among panic disorder patients, even after controlling for demographic and clinical status variables.