social psych 1 ssri vs placebo
TRANSCRIPT
1Running Head: SSRI ANTIDEPRESSANTS VS. PLACEBO TREATMENTS
Are SSRI Antidepressant Drugs Really Just a Placebo Treatment?
Christopher Daemen
Bishop’s University
Term paper
PSY 245A: Social Psychology I
Professor Leo Standing
Oct 28th, 2013
2Running Head: SSRI ANTIDEPRESSANTS VS. PLACEBO TREATMENTS
Abstract
In his 2008 study, Kirsch and his colleagues found that placebo’s are nearly as effective
in treating depression as Selective Serotonin Reuptake Inhibitors. This paper will shed some
light in the debate on whether SSRI antidepressant drugs are really just as effective as placebo
treatment by looking into some of the variables that deserve consideration when interpreting
Kirsch’s et al. 2008 results. Findings show a case can be made both ways. Psychiatrists, who
make their living prescribing antidepressants, defend the drug’s efficacy, whereas Psychologists,
who do not prescribe drugs, are more skeptical. Professionals must evaluate the patient’s
circumstances and offer hope, a sympathetic ear, practical advice, and, insight. In many cases,
after weighing the options, they may decide that an antidepressant may help.
3Running Head: SSRI ANTIDEPRESSANTS VS. PLACEBO TREATMENTS
Are SSRI Antidepressant Drugs Really Just a Placebo Treatment?
Introduction
In light of published articles suggesting that placebos offer a reasonably good treatment
for depression, we may wonder if SSRIs are more effective than placebo treatment, the inactive
substance believed to have no physical or chemical effect on the condition being studied, that
serves to keep studies double-blind. Given antidepressants are more costly than placebos and
have more undesirable side-effects, is the benefit worth the costs?
Background In 2008, Irving Kirsch and his colleagues published a meta-analysis of
placebo-controlled clinical trials of antidepressants reported to the FDA. The widely-reported
results were controversial.
4Running Head: SSRI ANTIDEPRESSANTS VS. PLACEBO TREATMENTS
As much as 80% of the positive response to these medications may have been a placebo
effect. The authors concluded that the popular drugs may have no pharmacological effect at all.
The Kirsch study showed an average drug-placebo difference of less than 2 points on the
Hamilton Rating Scale for Depression (HRSD), which is a 17 or 21 item scale administered by
the physician, that covers mood, thoughts and other symptoms of depressive illness, such as
sleep and appetite.
Purpose This paper will shed some light in the debate on whether SSRI antidepressant
drugs are really just as effective as placebo treatment by looking into some of the variables that
deserve consideration when interpreting Kirsch’s 2008 results.
Argument
What is called the placebo effect is the tendency for nearly any treatment to make people
feel better. In practice the placebo effect also stands for several non-specific factors associated
with treatment. At the turn of the century, these non-specific responses were becoming stronger
in trials of anti-depressant drugs; problematic, to say the least, for researchers. B. T. Walsh and
his colleagues looked at 75 randomized controlled trials published between 1981 and 2000 and
found that on average, the later the study, the stronger the response to placebo. The proportion
of the people responding to antidepressants in
these trials was also rising, though not as
rapidly. When placebo responses become
stronger, there is less room at the margins,
where the antidepressant’s effect can be seen
as found by Kirsch et al. in 2008.
5Running Head: SSRI ANTIDEPRESSANTS VS. PLACEBO TREATMENTS
One might argue that the trend is due to changes in the kinds of patients who participated
in these clinical trials. Twenty years ago, more of these patients were suffering from more
severe forms of depression. Those were the types of patients more likely to respond to
antidepressants and less likely to respond to a placebo. By 2008, many depressed patients were
already taking antidepressants. Because treatment was initiated earlier, fewer patients were
referred to studies. To cope with this shrinking pool of subjects, researchers turned to
advertising, which meant they were recruiting people with less severe symptoms. Researchers
may have felt pressure to inflate HAM-D scores in order to boost participation in these studies.
One may argue that study subjects up to 2008 may have had milder forms of depression, that
were more responsive to non-specific influences, such as the hope or anticipation of
improvement, the chance to talk about their problems with enthusiastic professionals trying to
find better treatments.
It is important to take into consideration that randomized controlled trials have their
limitations. Depression comes in many forms. It is not a single, simple condition. This
enormous variety makes it almost impossible to control for all the variables, even in a single
trial, and still more difficult to compare one trial with another. Also, because the Hamilton scale
contains only one direct question about depression, all the other items are less specific, so that
people with other problems, like anxiety, may score high. Hamilton developed the scale for the
most severely mentally ill. People with middling scores are a diverse group and may improve
for numerous reasons.
Furthermore, any scale, such as the HAM-D or CANMAT guidelines for depression is
only a rough approximation of a person’s experience. No researcher would begin to argue that
6Running Head: SSRI ANTIDEPRESSANTS VS. PLACEBO TREATMENTS
one number could describe what is happening biologically, physiologically and socially, when a
person becomes depressed.
Meta-analysis has its limits as well. Combining many results into a single number can be
misleading because studies vary so much in their design. They have different types of subjects,
with different types of depression. Some forms may respond to anti-depressants, some to
psychotherapy, some to both and some to a placebo. Thus, even treatments that seem equally
effective may help different patients.
What’s more is that there are more recent, competing analyses to defend the vast
literature demonstrating the effectiveness of antidepressants. In 2009, Cipriani and her
colleagues published work titled Comparative Efficacy and Acceptability of 12 New-Generation
Antidepressants: A Multiple-Treatments Meta-Analysis that found certain new-generation
antidepressants to be more effective than others in treating depression.
Conclusion
Kirsch’s 2008 meta-analysis then, need to be viewed through the proper lenses. Given
the limitations of meta-analyses and other factors such as baseline severity, the types and nuance
of depression, mixed in with variance in the types of people recruited for clinical trial one can
conclude that larger, more statistically powerful clinical trials will be more useful than meta-
analyses for answering questions about antidepressant efficacy. Psychiatrists, who make their
living prescribing antidepressants, defend the SSRI’s efficacy, whereas Psychologists, who do
not prescribe drugs, are more skeptical. Professionals must evaluate the patient’s circumstances
and offer hope, a sympathetic ear, practical advice, and, insight. In many cases, after weighing
the options, they may decide that an antidepressant may help.
7Running Head: SSRI ANTIDEPRESSANTS VS. PLACEBO TREATMENTS
References
Cipriani A, Furukawa T A, Salanti G, Geddes J R, Higgins J PT, Churchill R, Watanabe N,
Nakagawa A, Omori I M, McGuire H, Tansella M, Barbui C. (2009) Comparative
Efficacy and Acceptability of 12 New-Generation Antidepressants: A Multiple-
Treatments Meta-Analysis, The Lancet, 373(9665), 746-758, doi:10.1016/S0140-
6736(09)60046-5
Khan A, Faucett J, Lichtenberg P, Kirsch I, Brown WA. (2012) A Systematic Review of
Comparative Efficacy of Treatments and Controls for Depression PLoS ONE 7(7):
e41778. doi:10.1371/journal.pone.0041778
Kirsch I. (1985) Response Expectancy as a Determinant of Experience and Behavior.
American Psychologist, 40(11), 1189-1202. doi: 10.1037/0003-066X.40.11.1189
Kirsch I. (2005), Placebo Psychotherapy: Synonym or Oxymoron? J. Clinical Psychology, 61:
791–803. doi: 10.1002/jclp.20126
Kirsch I, Deacon BJ, Huedo-Medina TB, Scoboria A, Moore TJ, et al. (2008) Initial Severity and
Antidepressant Benefits: A Meta-Analysis of Data Submitted to the Food and Drug
Administration. PLoS Med 5(2): e45. doi: 10.1371/journal.pmed.0050045
Kirsch I, & Low C B. (2013) Suggestion in the Treatment of Depression,
American Journal of Clinical Hypnosis, 55(3), 221-229, doi:
10.1080/00029157.2012.738613
8Running Head: SSRI ANTIDEPRESSANTS VS. PLACEBO TREATMENTS
Kirsch I, Moore T J, Scoboria A, Nicholls S S. (2002) The Emperor's New Drugs: An Analysis
of Antidepressant Medication Data Submitted to the U.S. Food and Drug Administration.
Prevention & Treatment, 5(1): Article 23. doi: 10.1037/1522-3736.5.1.523a
Kirsch I, Sapirstein G. (1998) Listening to Prozac but Hearing Placebo: A Meta-Analysis of
Antidepressant Medication. Prevention & Treatment, 1(2), Article 2a. doi:
10.1037/1522-3736.1.1.12a
Walsh B T, Seidman SN, Sysko R, Gould M. (2002) Placebo Response in Studies of Major
Depression: Variable, Substantial, and Growing. JAMA. 287(14):1840-1847. doi:
10.1001/jama.287.14.1840.
Wampold B E, Minami T, Tierney S C, Baskin T W, Bhati K S. (2005), The Placebo is
Powerful: Estimating Placebo Effects in Medicine and Psychotherapy from Randomized
Clinical Trials. Journal of Clinical Psychology, 61: 835–854. doi: 10.1002/jclp.20129