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PPRNet Blog: May 2015

Giorgio A. TascaAt the PPRNet conference in November 2012 over 100 psychotherapy clinicians, researchers, and educators were very keen to receive ongoing information about psychotherapy research that is practice-oriented and presented in an easily readable format. And so the PPRNet Blog was born.

About once a month I will review and summarize two or three published psychotherapy research articles. As part of the summary, I will highlight the practice implications of the research.

Because of copyright issues, we cannot post the full text of the articles, but we will provide a link to the abstract on the publisher's web site. I will also post the author's email address. Most authors are very happy to share their work. So if you want a copy of the article send the author an email with a request for a pdf or reprint.

At the bottom of each review you can post a comment, and comment on your colleagues' comments. I will update these as frequently as possible.

If you have ideas for an article to review or a topic you would like to see covered, please send me an email at

Giorgio A. Tasca

blogWhy We Should Care About Allegiance Effects in Psychotherapy Research?

The Great Psychotherapy Debate

Starting in April, 2015 I will review parts of The Great Psychotherapy Debate that focus on efficacy of treatments, therapist effects, common factors, and more. This is the second edition of this landmark and sometimes controversial book that provides a historical and current survey of the evidence for what makes psychotherapy work. Since this is a book I will not provide the author email. However, you can view parts of the book in Google Books: The Great Psychotherapy Debate on Google Books.

Why We Should Care About Allegiance Effects in Psychotherapy Research?

Wampold, B.E. & Imel, Z.E. (2015). The Great Psychotherapy Debate: The evidence for what makes psychotherapy work (2nd edition). New York: Routledge.

Allegiance in psychotherapy refers to the degree to which a researcher or therapist believes that the therapy they are studying or delivering is effective. Clients have an expectation that therapists have an explanation for their disorder and that the therapy used to address that explanation will lead to improvements. On their part, psychotherapists choose a therapeutic approach that is consistent with their understanding of psychological distress. Wampold and Imel argue that therapist allegiance is a common factor across therapies that contributes to good patient outcomes. Although allegiance is an important therapeutic factor, it complicates the conduct of psychotherapy research. In a trial comparing two treatments, for example, researchers and therapists tend to be affiliated with one of the treatments and so they believe in the effectiveness of their treatment. They often do not feel the same way about the comparison treatment, or they may desire that their preferred treatment be more effective than the comparison. In medication trials, this allegiance effect can be controlled by a double blind placebo controlled design in which both therapist and patient are not aware of who is receiving which active medication, or who is receiving a placebo. It is impossible to blind therapists in psychotherapy trials – therapists have to know what treatment they are providing. When doing a meta analytic review of psychotherapy trials, it is possible and relatively easy to identify the allegiance of the researchers in a particular study by looking at their past publications, and by reading what they say about the therapies they are comparing. Often, the developer of a treatment manual is a co-author of the trial. Wampold and Imel review several meta analyses that assess the allegiance effects. In three meta analyses from published in 1980, 1999, and 2013 the correlation between ratings of researcher allegiance and effects of psychotherapy on patient outcomes ranged from moderate to large (r = .26 to r = .85). One interesting meta analysis illustrates the magnitude of this effect. The reviewers looked at 69 studies on self statement monitoring (SSM), a type of cognitive therapy developed by Meichenbaum. The average effect of SSM compared to controls in all studies was d = .53 to d = .74, which is moderate. However, effect sizes found in the studies co-authored by Meichenbaum were nearly twice as large, d = d = 1.23. Being a co-investigator in a study of a therapy that one develops, apparently doubles the effect of the treatment on patient outcomes.

Practice Implications

Therapist allegiance to a treatment is important to the effectiveness of the treatment in that therapist allegiance increases the therapist’s confidence in the treatment’s effectiveness and increases a patient’s expectation of getting better. However, when interpreting psychotherapy trials, especially those that pit one type of therapy against another, it is important to keep in mind the researchers’ allegiance. It is rare to see trials that compare two interventions in which the research team is made of up proponents of the two interventions. However such trials are important and necessary.

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blogIs Exposure Necessary to Treat PTSD?

Markowitz, J.C., Petkova, E., Neria, Y., Van Meter, P.E., Zhao, Y., … Marshall, R.D. (2015). Is exposure necessary? A randomized controlled trial of Interpersonal Psychotherapy for PTSD. American Journal of Psychiatry, 172, 1-11.

Post-traumatic stress disorder (PTSD) is a condition caused by experiencing or witnessing a terrifying event. Symptoms may include flashbacks, nightmares and severe anxiety, as well as uncontrollable thoughts about the event. PTSD has a lifetime prevalence of 6.8%, which makes it a highly prevalent disorder. The main technique of empirically validated psychological treatments for PTSD involve exposing patients to safe reminders of the trauma including memories, with the intent of extinguishing the fear responses. This is the basis of cognitive behavioural therapy (CBT) with prolonged exposure, which is a consensus treatment for PTSD. However, not all patients benefit from CBT with prolonged exposure, and such treatment may be too difficult for some patients and therapists to tolerate. Markowitz and colleagues argued that PTSD symptoms reflect interpersonal issues including interpersonal withdrawal, mistrust, and hypervigilance. Interpersonal psychotherapy (IPT) is a time-limited efficacious treatment for depression that was adapted for this study for non-exposure based non-CBT treatment of PTSD. IPT was modified so that the first half of treatment focused on recognizing, naming, and expressing feelings in non-trauma related interpersonal situations. The second half of treatment focused on common IPT themes such as role disputes and role transitions. The authors argued that IPT helps individuals with PTSD gain mastery over social interactions and mobilize social supports. The authors conducted a randomized controlled trial that had a sufficient sample size to test a hypothesis of “non-inferiority”, that is to adequately test if PTSD and exposure based CBT were equally effective. Both treatments were compared to a progressive muscle relaxation (PMR) control condition. In all, 110 participants with chronic PTSD were recruited and randomized to IPT, CBT, or PMR. Most patients reported trauma of 14 years duration from either sexual or physical abuse, and half had a current comorbid depression. All three interventions resulted in large significant reductions in PTSD symptoms. IPT (63%) and CBT (47%) were not significantly different in rates of response (i.e., in which response was defined as 30% improvement in a clinician administered PTSD scale), but IPT had a significantly higher response rate than PMR (38%). Patients with comorbid depression were more likely to drop out of CBT with prolonged exposure than IPT.

Practice Implications

The results of the study suggest that IPT and CBT with exposure were equally effective in reducing symptoms of PTSD. It is important to keep in mind that this is one well-conducted trial that needs to be replicated by independent researchers in order to establish if the findings are truly reliable. Nevertheless, the findings contradict the widespread belief that patients with PTSD require exposure-based treatment in order to improve. IPT may be another option for the treatment of PTSD, especially for patients who cannot tolerate the prolonged exposure. Patients with comorbid depression may have the most difficulty tolerating prolonged exposure therapy, and so they may benefit from IPT as an alternative. IPT may help patients gain abilities in social interactions and social support, which may make it easier for them to spontaneously expose themselves to recollections of trauma.

View the Is Exposure Necessary to Treat PTSD? article abstract.
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blogEffects of Antidepressants in Treating Anxiety Disorders Are Overestimated

Roest, A.M., de Jonge, P., Williames, G.D., de Vries, Y.A., Shoevers, R.A., & Turner, E.H. (2015). Reporting bias in clinical trials investigating second-generation antidepressants in the treatment of anxiety disorders: A report of 2 meta-analyses. JAMA Psychiatry, doi:10.1001/jamapsychiatry.2015.15.

Previous research has shown that the effects of antidepressant medications for treating depression may be over estimated by as much as 35%. This occurs because of publication bias, which refers to the tendency among researchers and editors to prefer to publish positive findings, and also occurs to the occasional practice of the pharmaceutical industry to suppress negative findings. In these meta analyses, Roest and colleagues assess publication bias in the research of antidepressant medications to treat anxiety disorders (i.e., generalized anxiety disorder [GAD], panic disorder [PD), social anxiety disorder [SAD], post traumatic stress disorder [PTSD], and obsessive compulsive disorder [OCD]). Anxiety disorders are very common in the population, with an estimated year prevalence of 12%. Second generation antidepressants (i.e., selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors) are the primary pharmacologic treatment for anxiety disorders. Roest and colleagues were also interested in outcome reporting bias, which refers to misreporting non-positive findings as if they were positive findings, and spin which refers to interpreting non-positive results as beneficial findings. Positive findings refer to the pharmacological agent significantly outperforming a placebo, and non-positive findings refer to pharmacological agents not significantly outperforming a placebo. Pharmaceutical companies in the US must register any trial with the Food and Drug Administration (FDA) prior to starting the trial if the company wishes to apply for US marketing approval. And so, all medication trials and their findings, whether positive or non-positive must be listed in the FDA register. Despite being listed with the FDA, not all trials and findings get published in peer reviewed journals. The main problem is that reviews and meta analyses tend only to focus on published trials, and prescribing physicians tend only to read published trials and reviews. In their meta analyses Roest and colleagues compared findings from all FDA registered medication trials to those that were published in peer reviewed journal. Fifty seven trials were registered with the FDA but only 48 were published. Regarding publication bias, the proportion of studies with positive findings indicating efficacy of antidepressant medications in FDA trials was 72%, whereas the proportion of studies with positive findings in published trials was 96%. Overall, trials were 5 times more likely to be published if they were positive than if they were non-positive. Regarding outcome reporting bias, 3 of 16 trials that were non-positive in the FDA review were reported as positive in journal publications. Regarding spin, an additional 3 of the 16 non-positive trials interpreted non-positive results as if they were positive. Effect sizes in the FDA data was g = .33 indicating a small average effect size of the medications for anxiety disorders, but the effect size in published journals was g = .38 indicating a small to moderate effect. This represents a 15% over estimation of the effects of the antidepressant medications for anxiety disorders in the published literature.

Practice Implications

The effects of antidepressant medications for anxiety disorders appear to be over estimated by 15% in the published literature. This inflation is not as large as the 35% over estimation in the published literature of the effects of antidepressant medications for depression. By contrast, as I reported in the May 2013 PPRNet Blog, publication bias in psychotherapy trials is small and has little impact on the overall estimate of psychotherapy’s efficacy. Effect sizes for psychological interventions for anxiety disorders are moderate to large, g = .73 . Combining medications and psychotherapy only modestly improves efficacy of treatments, and medications may interfere with the efficacy of psychological interventions.

View the Effects of Antidepressants in Treating Anxiety Disorders Are Overestimated article abstract.

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