Studies of Neuroimaging and Gene Interactions: Figures Don't Lie, Do They?

The discoveries of abnormalities in regional brain volumes and gene expression in psychiatric disorders are among the most impressive advances in neurobiology. Two European reports raise cautions about the interpretation of some of these results.

Ioannidis reviewed eight articles containing 41 separate meta-analyses with 461 data sets comparing regional brain volumes in healthy controls and patients with depression, bipolar disorder, obsessive-compulsive disorder, post-traumatic stress disorder, autism, or first-episode schizophrenia (one study examined relatives of schizophrenia patients; most studies used magnetic resonance imaging). The researchers used a test for “excess significance” to calculate how many data sets should have had posit…