Alterations in characteristic patterns of relating to the environment and the self that occur from social, psychological, or physical stressors such as having catastrophic experiences, having a mental disorder, or having a general medical condition (e.g., brain trauma). The personality shows a definite change from the preexisting personality; in children, there is a significant change from usual behavior patterns or a disruption in development. Features appear that were not present earlier, such as a hostile, mistrustful, or suspicious attitude; social withdrawal; feelings of emptiness or hopelessness; or poor impulse control or aggressive behavior.