This story does a good job of reporting on the research methods and findings. However, the research itself has some methodological concerns that could have (should have?) been examined more closely in the story. For example, one might question the plausibility that the benefits of taking fish oil supplements for only 3 months could extend to 1 year. These results may have been confounded by the fact that patients were allowed to take antidepressants and other medications. One might also wonder about the psychiatric state of the study population because researchers note that the risk of becoming psychotic over the course of 1 year is approximately 40%. This is considerably higher than that seen in the placebo group. Further, the results only apply to a small sample of children and young adults in a controlled clinical setting and are not generalizable. A limitation of this story is that it did not provide insights from an independent expert who could have highlighted the limitations of the research on which the story was based.
Schizophrenia-like illnesses can be devastating especially if untreated so the use of a dietary supplement that is widely available could be quite helpful. If replicated in a larger study, this would be quite a boon for such high-risk youth. The eye catching headline is followed by a reasonable summary and discussion of the study – although we yearned for more scrutiny of the methodology.
Estimated costs of fish oil supplements, approximately $0.40 per day, are provided.
Potential benefits reported in the research study, that significantly fewer patients became psychotic after taking fish oil supplements, are summarized in this story. Specifically, only 5% of participants who took fish oil transitioned to a psychotic disorder compared with 28% in the placebo group. It also indicates that there is generally a positive risk-benefit ratio with fish oil supplementation. Absolute numbers were given, along with the number needed to treat (NNT). These are big plus factors for th is story.
While fish oil supplements are generally recognized as safe, the story does not provide the reader with potential side effects which can be gastrointestinal and include blood clotting problems, particularly for people taking blood thinners. The story states: "Side effects of antipsychotics, including sexual dysfunction and weight gain, are troubling to young people, Amminger said. Fish oil, recommended for heart health, is more acceptable to patients with warning symptoms." But what does "more acceptable" really mean? This wholesale and widespread adoption of the supplement – by people who didn’t fit this study’s precise profile – has the potential to magnify harms and reduce benefit.
Our evaluaton of this criterion is complicated, but we think for good reason.
This story does a good job of summarizing the research methods and results in detail – mentioning t hat this was placebo-controlled and that there was random assignment to the study groups. The story could have also mentioned that this is a high quality, double-blinded study, meaning that the researchers and the patients were unaware of the treatment assignment to active fish-oil or to placebo. That’s a strength of the study that story didn’t mention. Bu the story also could have emphasized that this is quite a small study and the results were much better than could be predicted based upon previous research.
We also notice the inclusion of study subjects with cannabis use disorders–and there is reasonable evidence that heavy cannabis use can correlate with or precipitate first psychotic episodes. The authors did not report on potentially confounding use of cannabis after randomization. It is possible that the way they treated dropouts was not optimally conservative. Had dropouts in the placebo group been considered as healthy while those in the treatment group as worsened, then they could claim high rigor.
These are some of the things we look for in evaluating the quality of the evidence.
In balance, we’ll give this story the benefit of the doubt, while alerting readers to other factors to consider when evaluating studies.
This story describes schizophrenia as a "severe mental illness that strikes adolescents and young adults. About 2. 4 million Americans have the disorder…" But this study concerned only a few very high risk, highly selected patients evaluated at a busy medical center. So the story over-generalizes the applicability of the study. And beyond this, the story states that all the subjects who went on to meet criteria for one of the endpoints had "become psychotic or completely out of touch with reality." Could this be an overly dramatic description of the progression to an episode of psychosis that may last no more than a week? Granted, these are fines lines of semantics and interpretation, but we think stories need to employ a level of healthy skepticism that would raise some of these questions.
This story is based upon interview with the principal scientist who conducted research and interviews with 3 independent experts.
We’ll give the story the benefit of the doubt on this criterion because it did seek and present different expert perspecitves.
However, all of the experts expressed a positive view of the research findings. The main limitation of this story is that it did not provide insights from an independent expert who could have highlighted the limitations of the research on which the story was based and who could have presented an alternative point of view – the kind of perspective we can easily raise.
This story does compare treatment with fish oil supplements to an alternative treatment with antipsychotic medications. In addition, the story reports on potential harms of treatment with antipsychotic medication. It is not known whether this dietary supplement is as good as or worse than antipsychotic medication in this setting as they have not been compared in a head-to-head comparison.
It’s clear in the story that fish oil supplements are taken by many people for health reasons.
Other studies have examined the role of omega-3 PUFAs for treatment of patients with schizophrenia with inconsistent results. We didn’t hear about that in this story.
There’s no evidence that this story relied on a news release.