A study published in the open access journal, PLOS One by Sugarman et al. once again replicated previous studies showing that there was very little clinical difference between an antidepressant and placebo. In a way this is old news. One of the study’s authors, Irving Kirsch previously reported these findings. You can read more on this antidepressant research here and here. I’ve also looked at a 60 Minutes broadcast that interviewed him in “Thor’s Psychiatric Hammer: Antidepressants.” Kirsch has also published a book on the topic: The Emperor’s New Drugs: Exploding the Antidepressant Myth. But here is the significance of the Sugarman et al. study. It was the first evaluation to use “a complete database of published and unpublished trials sponsored by the drug’s manufacturer.”

In 2004, GlaxoSmithKline  (GSK) was required as part of a lawsuit settlement to post online the results of all clinical trials involving its drugs. The 2004 lawsuit was because the company had withheld data on the ineffectiveness and potential danger of Paxil (paroxetine) when given to adolescents and children. But it doesn’t seem GSK learned their lesson. In 2014 the company agreed to plead guilty to criminal charges and pay $3 billion in fines for promoting its antidepressant drugs, Paxil and Wellbutrin for unapproved uses and failing to report safety data about Avandia. So Sugarman et al. were able to use the data GSK made available to do the research reported here.

The current analysis is the first evaluation of the efficacy of an SSRI medication in the treatment of multiple anxiety disorders, and the first to utilize a complete database of published and unpublished trials sponsored by the drug’s manufacturer. Our results indicated that paroxetine presented a modest benefit over placebo in the treatment of anxiety and depression, with mean change score differences of 2.3 and 2.5 points on the HRSA [Hamilton Rating Scale for Anxiety] and HRSD [Hamilton Rating Scale for Depression], respectively.

The study’s results found that individuals receiving placebo reported 79% of the magnitude of change with the individuals receiving paroxetine. This was consistent to previously reported magnitudes of 76% for placebo compared to paroxetine. Replicating this previous finding, namely greater than 75% of the drug response, suggested that: “the magnitude of the placebo effect is especially large in the treatment of anxiety and depression.” Given the similarities between paroxetine and other SSRIs, it is possible that similar magnitudes of placebo effects will be found with them. Further research is required to support this proposition. Nevertheless, “the current analysis indicates that the published literature represents an overestimate of the true efficacy of paroxetine in the treatment of anxiety.”

The glass-half-full reporting of the differences between drug and placebo have emphasized that statistically significant differences were found. The problem is, those differences were so small, that their clinical significance was questionable. According to the criteria of NICE, the National Institute of Health and Clinical Excellence, “the mean difference between paroxetine and placebo in the current analyses fell short of clinical significance for the treatment of both anxiety and depression.” Sugarman et al. reviewed these concerns and concluded that changes of three points or less on the HRSD did not correspond to a clinically detectable change and appeared to be “of marginal clinical significance.”

So paroxetine has only a slight benefit over placebo in treating symptoms of anxiety and supports previous work indicating that it has just a modest benefit over placebo when treating depression. Given the known side effects with standard medications used to treat anxiety and depression, their use as a first-line treatment for these problems seems questionable. “The obvious alternative for the treatment of both anxiety and depression is psychotherapy intervention.” But direct comparisons have not generally shown a significant difference between depression treatment modalities (medication or psychotherapy). Similarly inconclusive findings were noted for anxiety treatment.

Allen Frances said there were two differences between medieval alchemy and the pharmaceutical industry today. First is the well-oiled, massively financed, worldwide, and devastatingly effective marketing machine. Second is the requirement for a DSM diagnosis.

A significant portion of the $12 billion spent each year on antidepressants in the United States rewards the drug companies for promoting the overly widespread use of what to many patients are no more than highly advertised, oversold, and very expensive placebos prescribed for a fake diagnosis. (Allen Frances, Saving Normal)

In 2010, there was a study published a Scandinavian psychiatric journal with the provocative title: “Antidepressant Medication Prevents Suicide in Depression.”  It concluded from studying 18,922 suicides in Sweden between 1992 and 2003, “that a substantial number of depressed individuals were saved from suicide by postdischarge treatment with antidepressant medication.” Sixteen months after publication, it was formally retracted by the authors for “… unintentional errors in the analysis of the data.”

Psychologist Phillip Hickey reported that after a five month legal battle, he was able to get access to the correct data. The original study found that among completed suicides treated for depression in psychiatric care in the last five years before their suicide, 164 (15.2%) had antidepressants in their blood when they committed suicide. The corrected data indicated that 603 (56%) had antidepressants in them when they committed suicide. The “unintentional error” was huge—an increase of 439 people (268%).

And yet, the study’s author said that no conclusion from the study could be drawn “regarding antidepressants’ effects on suicide risk in any direction.” In other words, you couldn’t conclude that antidepressants prevented or facilitated suicide risk. Hickey reported that at the time of writing the original article, its author has financial ties to Lundback, Eli Lily and GSK (GlaxoSmithKline).

In another study, found in The British Journal of Psychiatry, a team of UCLA researchers randomized 88 participants into double-blind groups for 8 weeks of treatment (placebo or medication) with supportive care; and a separate group receiving supportive care alone. Expectations of medication effectiveness, general treatment effectiveness and therapeutic alliance were also measured. The groups receiving medication or placebo plus supportive care were not significantly different. However, both had significantly better outcomes than the supportive care alone group. Expectations of medication effectiveness were predictive of only the placebo response. Therapeutic alliance predicted participant response to both medication and placebo.

The lead author of the study, Andrew Lechter, said that the results indicated that if you think a pill is going to work, it probably will work. He noted that belief in the effectiveness of the medication was not related to the likelihood of benefitting from it. “Our study indicates that belief in ‘the power of the pill’ uniquely drives the placebo response, while medications are likely to work regardless of patients’ belief in their effectiveness.” He speculated that factors like direct-to-the-consumer advertising could be shaping peoples’ attitudes about medication. “It may not be an accident that placebo response rates have soared at the same time the pharmaceutical companies are spending $10 billion a year on consumer advertising.”

It seems that Lechter is saying that the drug response was independent of the expectations of medication effectiveness, while the placebo response was driven be the prior expectations of the participants, as they were influenced by factors like direct-to-the-consumer advertisings. If true, this would seem to challenge, to a certain extent, the results noted above and in Kirsch’s previous research. Replication of the results is needed before Lechter’s conclusions from his research are accepted. It should be pointed out that paroxetine (Paxil) was approved by the FDA in May of 1996, while direct-to-the-consumer advertising of medications did not begin until 1997. Therefore, it would not have had an effect upon the paroxetine data reported above. I would also feel more comfortable with Lechter’s interpretations of his data if he didn’t have as extensive an association with the pharmaceutical industry. See the “Declaration of interest” in the linked abstract from The British Journal of Psychiatry.