Psychologists have found that two common questionnaires for assessing depression don’t work for comparing people of differing intelligence—and the problem may extend to other conditions and traits.
For a recent study in the journal Intelligence, Stanisław Czerwiński of the University of Gdańsk in Poland and his colleagues investigated how intelligence correlates with mental health. They hypothesized that the association between intelligence and better mental health starts out positive as it approaches the high end of the IQ scale, then turns negative.
The data revealed the curved relation the researchers were expecting: the highest intelligence levels seemed to be associated with declines in mental health. But then the scientists found a problem. To make sure their results were valid, they ran statistics tests to determine whether the mental health measures work the same for people at different intelligence levels, in part by calculating whether responses to individual questions reflect depression to the same extent for everybody. Both scales failed this test, meaning they can’t be used to compare people with differing intelligence—and conclusions like this study’s can’t be trusted.
An interesting read. It never struck me as something that needed researching - the obvious bias baked into any and all tests which utilize language and probe at abstract ideas like feelings. It seems obvious to me that the idea of "sadness" is both inherently as well as culturally determined. For anyone who's dealt with individuals with varying amounts of alexithymia its glaringly obvious that some of the standard questions such as "feeling down, depressed, or hopeless" (PHQ9) would be interpreted differently, let alone questions in which context is crucially important such as "poor appetite or overeating" (PHQ9) or "being so restless that it is hard to sit still" (GAD7 - a test about anxiety) that are common on these kinds of questionnaires. Perhaps its because my interaction and discussions with clinicians tends to be folks who are focused more on the total mental wellness of someone than they are about the specific answers to a question and are using the context of the patient's other conditions and affect to assess, but this hardly seems groundbreaking... except that perhaps the literature on this itself is minimal. Perhaps this kind of clinical awareness has been handed down, rather than studied, and the corpus of literature needs to be enhanced so that more can learn and absorb it.