Why I can’t believe the new Cochrane review on the efficacy of psychedelics.

I have read the new Cochrane report on psychedelics (disclosure, I’m a lead author). I’m not sure why anyone would believe the conclusions that we reached. <br><br>The three main problems with the review are:<br><br>1. We relied on a small number of studies of low/very low quality with high risk of bias. <br>2. Essentially all studies were privately funded. Private funding is associated with a higher effect size than publicly funded studies. <br>3. This means, unfortunately, that we can’t be confident in the results we got.<br><br>We struggled to find high quality, publicly funded studies to include in the review. Those that were published had minimal detail available on them, so we couldn’t assess their quality, and they weren’t of high quality in the first place. It’s difficult to interpret all of the results (positive, null, or negative) in the context of the low quality of the studies included. This is why our review was published with a number of grade increments and decrements in quality in the summary of findings table, as we can’t be confident in any of the results. <br><br>The Cochrane review of psychedelics says:<br><br>“For depression, we are uncertain whether psychedelics were any more effective than placebo, antidepressants, or psychotherapy as it is unclear whether treatment with psychedelics has an impact on long-term outcomes.”<br><br>“For anxiety, we are uncertain whether psychedelics were any more effective than placebo or psychotherapy as it is unclear whether treatment with psychedelics has an impact on long-term outcomes.”<br><br>“For PTSD, we are uncertain, whether psychedelics were any more effective than placebo or psychotherapy as it is unclear whether treatment with psychedelics has an impact on long-term outcomes.”<br><br>“For substance use disorder, we are uncertain whether psychedelics were any more effective than placebo or psychotherapy as it is unclear whether treatment with psychedelics has an impact on long-term outcomes.”<br><br>“For smoking cessation, further research is very likely to have an important impact on our confidence in the effect estimate and is likely to change the estimate.”<br><br>In the review, we say: “It is unclear whether patients with mental health disorders benefit more from psychedelics than from other treatments, including psychotherapy and antidepressants, because of the low certainty of evidence and the shorter treatment duration. Future studies are needed to compare outcomes of psychedelics with other treatments over longer follow-up periods.” <br><br>We conclude the review by saying: “At present, we recommend caution with the prescription of psychedelics, if at all, until more high-quality trials are conducted. It is unclear whether patients with mental health disorders benefit more from psychedelics than from other treatments, including psychotherapy and antidepressants.”<br><br>We’re very disappointed that so many studies were of low quality, and that there is so little publicly available information about them. The majority of the studies had commercial funding, which is associated with a greater effect size. A lot of the studies had links to for-profit companies, and some had major methodological flaws. A lot of the studies were at high risk of bias. This brings into question the results found in the studies and included in the review.<br><br>I don’t think that anyone should believe our review until we’ve had time to see the results of some high quality, publicly funded studies. This is especially true given that the first generation of psychedelic drugs used in the studies included in the review are about to go off patent, and more expensive, branded versions of those drugs will shortly be brought to market. I hope that a useful approach is to wait for the results of the studies currently in progress to see which products are found to be effective and safe for mental health disorders. <br><br>The facilities and recruitment for those studies have already been paid for by the tax payer and by private industry, and I have no doubt that whatever the results are, they will be promoted widely by commercial interests, the media, and other key opinion leaders in order to direct patients and clinicians towards the most expensive and most widely available services and drugs. I hope that there will continue to be a place for cheap, generic drugs and for cheaper psychotherapies in the treatment of mental health disorders that are accessible to patients without access to these newer and more expensive treatments.