IMPORTANCE OF THE FIELD: Expansion and ultimately homeostasis of neural cell number is exquisitely regulated by molecular genetic networks operating in neural stem and progenitor cells (NSPCs) and in the neural stem cell niche during embryogenesis and in the adult brain. Transcription factors are crucial in orchestrating the correct cell-specific and temporal expression of all factors involved in these signalling networks. Aberrant expression of these factors can lead to abnormal brain development if this occurs during embryogenesis. In the adult brain, loss of neurogenic potential can lead to cognitive deficits and in combination with neural death can even contribute to neurodegenerative disease progress. AREAS COVERED IN THIS REVIEW: This review focuses on a number of recent discoveries identifying the role of the transcription factor cAMP response element binding (CREB) protein in regulating brain development and neurogenesis in the adult brain. WHAT THE READER WILL GAIN: The significance of these discoveries is presented in the context of human brain disorders and how this knowledge could contribute to pharmacotherapeutic interventions targeting CREB signalling aimed at treating such diseases. TAKE HOME MESSAGE: Unravelling these precise molecular genetic networks is crucial to understanding how neural stem and progenitor cells function.