Figure 1

Hippocampal and peripheral NRG1/ErbB gene expression in cases and controls. Hippocampal expression of NRG1 (a), ErbB1 (EGFR; b), ErbB2 (c), and ErbB4 (e) does not differ between controls and suicides regardless of antidepressant treatment; however, ErbB3 expression (d) is reduced. Reduced hippocampal expression of ErbB3 in suicides is not due to changes in ErbB3 methylation (f), as unmedicated suicides did not differ from controls in terms of CpG methylation. However, antidepressant usage was associated with increased methylation in a cluster of CpGs located around the ErbB3 promoter region near the transcription start site, in an area enriched in transcription factor binding sites. Numbers in bars denote numbers of subjects included in analysis. *P<0.05; **P<0.01; ****P<0.0001. AD, antidepressant; CTRL, control.