Sunday, October 13, 2013
Panic Disorder Study
Dr. Amos at The Practical Psychosomatacist has already eloquently described the article on Panic Focused Psychodynamic Psychotherapy, but this is my take.
Once again, here's the Abstract:
Objective: The purpose of this study was to determine the efficacy of panic-focused psychodynamic psychotherapy relative to applied relaxation training, a credible psychotherapy comparison condition. Despite the widespread clinical use of psychodynamic psychotherapies, randomized controlled clinical trials evaluating such psychotherapies for axis I disorders have lagged. To the authors’ knowledge, this is the first efficacy randomized controlled clinical trial of panic-focused psychodynamic psychotherapy, a manualized psychoanalytical psychotherapy for patients with DSM-IV panic disorder. Method: This was a randomized controlled clinical trial of subjects with primary DSM-IV panic disorder. Participants were recruited over 5 years in the New York City metropolitan area. Subjects were 49 adults ages 18–55 with primary DSM-IV panic disorder. All subjects received assigned treatment, panic-focused psychodynamic psychotherapy or applied relaxation training in twice-weekly sessions for 12 weeks. The Panic Disorder Severity Scale, rated by blinded independent evaluators, was the primary outcome measure. Results: Subjects in panic-focused psychodynamic psychotherapy had significantly greater reduction in severity of panic symptoms. Furthermore, those receiving panic-focused psychodynamic psychotherapy were significantly more likely to respond at treatment termination (73% versus 39%), using the Multicenter Panic Disorder Study response criteria. The secondary outcome, change in psychosocial functioning, mirrored these results. Conclusions: Despite the small cohort size of this trial, it has demonstrated preliminary efficacy of panic-focused psychodynamic psychotherapy for panic disorder.
Following are a series of figures from the study, that tell you a little about how Psychoanalytic Psychotherapy for Panic Disorder works:
So the psychodynamic conception of panic is that it has unconscious meaning, often related to conflicts surrounding separation, autonomy, and anger, and treatment starts out by trying to determine what those meanings are.
Phase II involves addressing transference to examine the way the conflicts causing the panic can play out in real time.
Phase III involves more transference. I'm a little confused about the difference between how the transference is addressed in Phase II vs. Phase III, except that Phase III involves talking about termination, which must stir up feelings about separation.
And here is a glimpse at the results:
Some strengths of the study were that it treated a pretty sick cohort, with a lot of comorbidities, and that its methodology was quite rigorous, including adherence to a manual, training of clinicians, and supervision. Also it addresses the question of why a new method of treatment for panic disorder is necessary, namely, that 29%-48% of patients do not respond to treatment with CBT or meds, and 25%-35% drop out of those treatment modalities. The dropout rate for PFPP in this study was 7%, vs. 34% for ART. Not clear what this implies-perhaps PFPP is more tolerable, For one thing, it doesn't involve homework or exposure.
A weakness is that it compared with applied relaxation training (ART) rather than CBT. I had assumed this was a logistic/funding issue, but I contacted Dr. Milrod, and she repeated what was written in the paper, but for some reason I understood it better the second time around. Namely, that if you have a new treatment, drug or otherwise, and you don't yet know if it works, then you need to test it against placebo. If you just test it against a treatment that is already known to work, then you won't have any actual information.
For example, suppose they had tested PFPP directly against CBT. If the results for both PFPP and CBT had been good, then you wouldn't know if both treatments work, or if neither treatment is doing anything in this particular setting, but people got better spontaneously. If CBT results were better than PFPP, then you wouldn't know if PFPP doesn't work at all, or just works less well than CBT. And if PFPP results were better than CBT, you still wouldn't know if, for some weird reason, the PFPP subjects spontaneously did better, and PFPP doesn't actually work.
And the reason you wouldn't know any of this is that you don't have a placebo control, which would tell you what happens to subjects who are given no therapeutic intervention. I hope that was clear. And I'm not sure why you couldn't have three arms, PFPP, CBT and placebo.
In any case, this brings up the question of what constitutes placebo in a psychotherapy trial. According to Dr. Milrod, ART was chosen because it was known to be an "efficacious but less active therapy for Panic Disorder" (personal communication). There's a nice discussion of the therapy placebo issue here (also by Dr. Milrod).
Finally (re: comparison with CBT issue), the FDA's Guidance for Industry in Non-Inferiority Clinical Trials states: “In order to implement an equivalence or noninferiority trial, the magnitude [of medication] effect must be stable and well-established in the literature, with consistent results seen from one trial to the next.” And according to our study, this level of stability in magnitude of effect for Panic Disorder does not yet exist.
So you can't say PFPP is equivalent, or at least non-inferior to CBT because you can't say just how good CBT is for Panic Disorder.