Evidence map›Paper›PMID 23889231›Full record

SynthesisAlcoholism, clinical and experimental research2013

The placebo effect in clinical trials for alcohol dependence: an exploratory analysis of 51 naltrexone and acamprosate studies.

Raye Z Litten, I-Jen P Castle, Daniel Falk, Megan Ryan, Joanne Fertig, Chiung M Chen, Hsiao-ye Yi

Open access · bronzeAbstract readMeta-Analysis
In one paragraph

Synthesis in Alcoholism, clinical and experimental research, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 33 papers, 6 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
33citing papers in PubMed, 6 pooled it
1.4field-weighted citation impact, top 20% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

33 citing papers in PubMed, 6 syntheses or guidelines pooled it, 55 citations in OpenAlex.

  1. Pooled it
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  4. Study Characteristics Influence the Efficacy of Substance Abuse Treatments: A Meta-analysis of Medications for Smoking Cessation.Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco · 2020
    Pooled it
  5. The placebo effect and its clinical associations in gambling disorder.Annals of clinical psychiatry : official journal of the American Academy of Clinical Psychiatrists · 2017
    Pooled it
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  13. Precision Medicine in Alcohol Dependence: A Controlled Trial Testing Pharmacotherapy Response Among Reward and Relief Drinking Phenotypes.Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2018
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  19. Preregistered multi-site preclinical randomized controlled trials: the beginning of a new day in reverse translational science?Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2025
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors at 2 institutions in 1 country.

Raye Z LittenDivision of Treatment and Recovery Research , National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland.
I-Jen P Castle
Daniel Falk
Megan Ryan
Joanne Fertig
Chiung M Chen
Hsiao-ye Yi
National Institute on Alcohol Abuse and Alcoholism · USCenter for Scientific Review · US

Funding

Intramural NIH HHS Z99 AA999999NICHD NIH HHS HHSN275201100002CNICHD NIH HHS HHSN275201100002G
6 · The paper itself

Abstract

backgroundThe placebo effect often undermines efforts to determine treatment effectiveness in clinical trials. A significant placebo response occurs in alcohol trials, but it is not well understood. The purpose of this study was to characterize the placebo response across multiple naltrexone and acamprosate studies.

methodsFifty-one trials, 3 with a naltrexone and an acamprosate arm, 31 with at least 1 naltrexone arm, and 17 with at least 1 acamprosate arm, were identified from Cochrane reviews and PubMed search. To be included in this study, patients had to be at least 18 years old, abstinent from alcohol before randomization, and meet a diagnosis of alcohol dependence. Pearson correlation coefficients (rp ) and simple linear regression were used to describe the strength of linear relationships between placebo response and treatment effect size. Spearman's rank correlation coefficients (rs ) were used to examine the strength of associations between study characteristics and placebo response.

resultsFor the end point measures of percent days abstinent and total abstinence, a negative relationship was evident between placebo response and treatment effect size in the naltrexone trials (rp  = -0.55, p < 0.01 and rp  = -0.20, p = 0.35, respectively) as well as in the acamprosate trials (rp  = -0.45, p = 0.09 and rp  = -0.56, p = 0.01, respectively). The placebo response for percent days abstinent was negatively correlated with mean age of participants (rs  = -0.42, p = 0.05) across naltrexone trials and positively correlated with publication year (rs  = 0.57, p = 0.03) across acamprosate trials. However, these 2 study characteristics were not significantly correlated with treatment effect size.

conclusionsThe placebo response varied considerably across trials and was negatively correlated with the treatment effect size. Additional studies are required to fully understand the complex nature of the placebo response and to evaluate approaches to minimize its effects.

Indexed as

Alcohol DeterrentsPlacebo EffectRandomized Controlled Trials as TopicAcamprosateAdultAlcoholismFemaleHumansMaleMiddle AgedNaltrexoneNarcotic AntagonistsTaurineTreatment OutcomeAcamprosateAlcohol DeterrentsNaltrexoneNarcotic AntagonistsTaurineAcamprosateAlcohol DependenceMeta-AnalysisNaltrexonePlacebo Effect

Identifiers

PMID23889231
PMCPMC3823636
OpenAlexW1977068881

What OpenQuestion holds

Textmetadata
LicenceTDM
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.