Impact of Publication Bias on Perceived Efficacy of Xanax in Treating Anxiety

Xanax’s effectiveness for treating anxiety may be exaggerated due to publication bias inflating the efficacy, according to a study published in Psychological Medicine.

Xanax is a medication commonly prescribed for panic disorder in the US. However, findings from this study indicate that it may not be as effective as previously thought. Researchers report that publication bias in medical journals has inflated the effectiveness of Xanax for panic disorder by over 40%.

“With publication bias, aka selective publication, there is a process of picking and choosing which study results do and do not get published, with the result of making the drug look better,” Dr Erick Turner, professor of psychiatry at the Oregon Health & Science University School of Medicine, former US FDA reviewer, and co-author of the study explained.

The study investigated the evidence of publication bias in the context of benzodiazepines, focusing on Xanax XR. Due to the difficulty in accessing FDA reviews for older benzodiazepines, the study centered on Xanax XR, approved in 2003. Researchers analyzed publicly available phase 2 and 3 clinical trial data from the US FDA concerning the treatment of panic disorder with Xanax XR. Out of 5 conducted trials, only 3 were published in medical journals. The FDA's review of these trials revealed that only one in five demonstrated a positive outcome when comparing Xanax XR's efficacy to a placebo.

The importance of understanding publication bias stems from its significant impact on clinical decision-making and the general public's perception of medical treatments. Dr Nathan A. Carroll notes that this bias can cause "availability bias," leading to decisions based mainly on positive research findings, which may not fully reflect a drug's effectiveness or safety. Dr David Merrill warns that this selective reporting can compromise the informed consent process by not providing a complete risk-benefit profile of treatments.

To mitigate publication bias, Dr Erick Turner suggests that researchers conducting systematic drug reviews should incorporate unpublished clinical trial data from regulatory agencies like the FDA to understand a drug's effectiveness better. He also recommends adopting the 'Registered Reports' peer review model, which commits to the publication of study outcomes regardless of the results, to ensure a more balanced representation of drug efficacy and safety in the medical literature. This approach aims to enhance transparency and reliability in medical research, allowing for more informed clinical decisions and public knowledge.

“First, publishers can commit researchers willing to publish negative results. Second, a database should be created so researchers can register their hypotheses. This will make it harder to change or cherry-pick results later. This would also be consistent with the study’s suggestion regarding ‘the value of regulatory data to the public,’” said Dr Carroll.

“Finally, there is the question of transparency and whether the industry has an ethical obligation to publish negative results,” he added.

References

Ahn-Horst RY, Turner EH. Unpublished trials of alprazolam XR and their influence on its apparent efficacy for panic disorder. Psychol Med. Published online October 19, 2023. doi:10.1017/S0033291723002830

Pelc C. Xanax’s effectiveness for treating anxiety may be exaggerated. Medical News Today. Published October 31, 2023. Accessed February 28, 2024. https://www.medicalnewstoday.com/articles/xanaxs-effectiveness-for-treating-anxiety-may-be-exaggerated