Our results differ from previous studies as we did not identify Wnt, Notch or BDNF as the most important mediators of progenitor differentiation, rather our work implicates the importance of the transcription factors EGR1, CEBPD and particularly EGR2. We believe the data generated within our study provides a resource for others to test for further biological associations, and our data also suggests novel targets for drugs which aim to increase hippocampal volume in the treatment of psychiatric disease. This evidence concerns the gene CEBPD and psychiatric disorder.