The generation of new neurons in the adult brain is modulated by complex stimuli and a broad range of extrinsic signals. It remains a mystery how stem cells and their progeny integrate this wealth of regulatory input to generate a precise number of neurons that matches the physiological needs of the olfactory and hippocampal network. cAMP response element binding protein (CREB)-dependent signalling is controlling essential developmental steps in adult neurogenesis, i.e. survival, maturation and integration of new neurons. Here, we summarize the current knowledge on the function of CREB in adult neurogenesis and discuss the potential of CREB to integrate complex stimuli and to translate these into precise developmental processes in adult neurogenesis. The complex modulation of CREB-signalling may allow the adult neurogenic system to respond to stimuli in a fine-tuned rather than in an on-off fashion.