Psychotic Links

Recent headlines about psychotic links to obesity might be a sign. Perhaps the word “link” — indisputably a four-letter word — is becoming offensive in health reporting. The word’s use is growing out of control in stories related to health and obesity. Ask Google for recent news stories about “obesity link” and you’ll get 8.6 million results to wade through.

The latest source of headlines is a study that reports an association between maternal obesity and the risk of psychosis in children. The authors of the study, presented at the 15th International Congress on Schizophrenia Research (ICOSR), emphasized the importance of their findings by saying:

This is now the fourth large study to show a positive association between maternal prepregnancy obesity and psychosis outcomes. It appears that prepregnancy obesity may be casting a long shadow into lives of offspring.

Familiarity bias works its way into the scientific literature and popular health lore through such reporting and repeated exposure to an idea. Someone stumbles upon an association and says, “this merits further research.” Then more studies find evidence of that association. Headlines pop up saying “yet another study shows obesity linked to psychosis.” Pretty soon it’s the “well-known link between obesity and psychosis.” Critical thinking about research starts getting dismissed. Who wants to be a party pooper?

With enough repetition, assumptions about causality become entrenched. The assumption in this case is that maternal obesity is causing an elevated risk of psychosis in children. But the truth is that the reason for this association is unknown. Other factors that cause both obesity and psychosis may be at work.

Redundant studies of links between obesity and this or that are a tiresome waste. They breed false assumptions and add nothing to the understanding of obesity. The energy should go into more novel research to test presumptions about what’s being observed.

Click here to read more about this study in Medscape. Click here for the study abstract. Click here for more on the repeated exposure effect and familiarity bias.

Linked, photograph © arbyreed / flickr

Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.