A new study of human brain tissue from suicide victims may provide insights into the neurobiology of suicide. Klempan et al. (pages 824–831) provide evidence for reduced QKI gene expression levels and levels of the QKI protein in the brains of suicide victims with major depression compared to controls, across multiple brain regions. No evidence of genetic or epigenetic changes in the vicinity of the QKI locus was identified. These alterations suggest that deficits in myelination-related pathways may underlie multiple psychiatric disorders.