There is a growing understanding that pathological genetic variation and environmental insults during sensitive periods in brain development have long-term consequences on brain function, which range from learning disabilities to complex psychiatric disorders such as schizophrenia. Furthermore, recent experiments in animal models suggest that therapeutic interventions during sensitive periods, typically before the onset of clear neurological and behavioral symptoms, might prevent or ameliorate the development of specific pathologies. These studies suggest that understanding the dynamic nature of the pathophysiological mechanisms underlying psychiatric disorders is crucial for the development of effective therapies. In this Perspective, I explore the emerging concept of developmental windows in psychiatric disorders, their relevance for understanding disease progression and their potential for the design of new therapies. The limitations and caveats of early interventions in psychiatric disorders are also discussed in this context.