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The origins of mental disorders: information is often biased

Scientific publications and the mainstream media alike exaggerate the role of biology and genetics in mental disorders.

What are the principal causes of mental disorders? Are they mainly biological, calling for a drugs-based approach? Or are they environmental, calling for psychological or socioeconomic measures? The answer seems to be distorted by biased reporting of study results in the media.

Neurobiologists examined articles on attention deficit hyperactivity disorder (ADHD) published in the mainstream media and in scientific publications. They particularly examined articles relating to possible genetic origins for this syndrome, and a possible link to dopamine deficiency.

This study showed that the mainstream media clearly overestimated the role of genetics, as well as the link with dopamine. But this bias was originally present in the scientific articles themselves. In fact, the authors found many biases in the scientific publications: large distortions between the results and the conclusions drawn; firm conclusions in the study abstract whereas important limitations were described in the body of the article; unwarranted extrapolations of preclinical results presented as promising therapeutic solutions; etc.

These biases are partly explained by the fact that it is easier to get published in major scientific publications when there is therapeutic potential, and also easier to obtain funding for research. This observation extends beyond ADHD and applies to all of the neurosciences, most notably as regards depression.

This type of biased presentation helps to encourage the search for drugs-based treatments, to the detriment of psychological measures or societal change. And carries the risk of overmedication that is of little or no real use, but the adverse effects of which are all too real.

©Prescrire 1 December 2012

"Neuroscience: reporting bias" Prescrire Int 2012; 21 (133): 306. (Pdf, free).

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