by Carla Clark, PhD | November 7, 2015
This might be a hard pill to swallow for both
those in treatment for depression and those giving treatment to
clients: both psychotherapy and antidepressant medications are beginning
to be considered to have rather limited contributions to the
effectiveness of treating depression. Some researchers and clinicians
alike are considering that for some, the placebo effect might be the
most powerful treatment of all.
A series of both research and opinion-based articles are suggesting
that we may have been focussing on the wrong thing all along. Research
into the placebo effect
and spontaneous recovery from depression, and indeed other mental
health problems, may be the way forward for both pharmacotherapy and
psychotherapy.
Hot in the news at the moment is a position emission tomography (PET)
study suggesting that some people are indeed more responsive to the intention to treat their depression, as opposed to the treatment itself.
The results indicate that those who can muster their brain’s own chemical forces against depression when
receiving a placebo, also appear to have a head start in overcoming its
symptoms with help from an approved antidepressant.
But those whose brain chemistry didn’t react as much to the placebo
pill given in the study, struggle even after getting an official antidepressant.
Although unexplored this could involve internal positive or negative
beliefs about treatment, either promoting or inhibiting the placebo
effect respectively.
The findings support scientific perspectives and opinions discussed in a series of placebo effect articles published in World Psychiatry,
including highly acclaimed scientists such as the President of the
European College of Neuropsychopharmacology, Dr. Stuart Montgomery, who
authored the article “Antidepressants or antidepressants plus placebo?”
While public opinion is certainly suspicious about the ability of
antidepressants to treat depression, as well as the pharmaceutical
industry’s intentions in finding rewarding outcomes in efficacy studies,
researchers have also grown increasingly skeptical regarding treatment
efficacy studies over the years.
There is a realization that the we need even greater accuracy in
distinguishing treatment effects from placebo in order to determine the
true efficacy of the treatment. Our current general standard of
randomized, placebo-controlled trials just doesn’t quite cut it.
In one article entitled, “What if a placebo effect explained all the
activity of depression treatments?” the key problem is posed:
“Due to the discrepancy between the relatively high rateThis may initially sound absurd to some, but there are sound
of spontaneous remission and the low additional value of specific
(pharmacological and psychological ) treatments, several important
issues arise. One question is whether these treatments do in fact have
any effects.”
arguments behind this line of thinking, only some of which are mentioned
in this article.
Some of the most recent meta-analyses reveal relatively small effect sizes of 0.30 for antidepressants and 0.25 for psychotherapies,
with only the highest quality of studies being able to show these small
effects. This roughly equates to only 15% of the variance in treatment
outcome being a result of the treatment itself, which is in the same
range as many accepted treatments in general medicine.
Dr. Montgomery suggests that even though these studies aim to remove
all biases, many may still remain. He used an example supported by a
recent article exploring differences between active placebos (those that
produce side-effects) and antidepressants for depression. A placebo
pill that does not produce noticeable side-effects may make the test
subject aware that they are indeed receiving placebo and reduce their
expectations of success, thus biasing results in favor of the treatment
being assessed.
With further advancements in the tweaking of methodologies to remove
remaining biases, perhaps there is almost no effect from the actual
treatment itself.
Indeed, there has been a constant increase in placebo response to
fake antidepressants in efficacy trials over the last decade, especially
in the US. This is thought to be due to many combinatorial factors,
such as more effective and intensified marketing of antidepressants and
the increased contact between study participants and clinical staff in
more modern and rigorous studies where participants are closely
monitored. This enhanced placebo effect may in fact be making it hard to
differentiate placebo from drug responses, and make antidepressants
appear to have a small effect size when they may be greater.
While research has been fervently focusing on the neurological and
psychological changes in response to various therapies, perhaps research
into spontaneous remission and the placebo effect should at least be of
equal importance.
As put by Dr. Marta Pecina, lead author of the PET study and research assistant professor in the U-M Department of Psychiatry:
“We can envision that by enhancing placebo effects, we might be able to develop faster-acting or better antidepressants.”The same can be said for psychotherapy treatments, were aspects of
interventions that facilitate the placebo effect, on top of any true
treatment effects, may be more effective than current treatments.
References
Cuijpers P, & Cristea IA (2015). What if a placebo effect explained all the activity of depression treatments? World psychiatry : official journal of the World Psychiatric Association (WPA), 14 (3), 310-1 PMID: 26407786
Cuijpers
P, Turner EH, Mohr DC, Hofmann SG, Andersson G, Berking M, & Coyne J
(2014). Comparison of psychotherapies for adult depression to pill
placebo control groups: a meta-analysis. Psychological medicine, 44 (4), 685-95 PMID: 23552610
Khan A, & Brown WA (2015). Antidepressants versus placebo in major depression: an overview. World psychiatry : official journal of the World Psychiatric Association (WPA), 14 (3), 294-300 PMID: 26407778
Montgomery SA (2015). Antidepressant or antidepressant plus placebo effect? World psychiatry : official journal of the World Psychiatric Association (WPA), 14 (3), 303-4 PMID: 26407781
Peciña,
M., Bohnert, A., Sikora, M., Avery, E., Langenecker, S., Mickey, B.,
& Zubieta, J. (2015). Association Between Placebo-Activated Neural
Systems and Antidepressant Responses JAMA Psychiatry DOI: 10.1001/jamapsychiatry.2015.1335
Walsh
BT, Seidman SN, Sysko R, & Gould M (2002). Placebo response in
studies of major depression: variable, substantial, and growing. JAMA, 287 (14), 1840-7 PMID: 11939870
