This publication shortly reviews some latest studies in which development of posttraumatic stress disorder (PTSD) is discussed from the point of view of complex interaction between genetic, environmental and personality variables. PTSD is an ideal disorder from this point of view because it requires exposure to traumatic stressors. On the other hand very much depends on the past experience. Parental styles may have long lasting consequences for the individual responsiveness to stressors with regards of the genetic makeup. This reactivity is explained through epigenetic changes involving transcription factors, cortisol receptor being one of them. Existing experimental data are in good concordance and it is possible to suggest a model for PTSD development based on G×E.