What type of disorder involves re-experiencing traumatic events through distressing memories or flashbacks?

Post-traumatic stress disorder (PTSD) is characterized by the re-experiencing of traumatic events, which can manifest as distressing memories or flashbacks. Individuals with PTSD often find themselves reliving the trauma, leading to significant distress and functional impairment. This disorder arises after exposure to a traumatic event, such as warfare, natural disasters, or personal assault, and it's marked by symptoms like avoidance of reminders of the trauma, negative changes in mood and cognition, and hyperarousal.

The focus on distressing memories and flashbacks distinguishes PTSD from other anxiety disorders. For instance, obsessive-compulsive disorder primarily involves intrusive thoughts and compulsive behaviors, rather than re-experiencing trauma. Panic disorder is characterized by sudden episodes of intense fear or discomfort, and seasonal affective disorder is related to changes in mood due to seasonal variations, particularly winter. Thus, PTSD's specific nature of reliving traumatic experiences makes it the correct choice for this question.