## **Core Concept**
The question describes a clinical scenario where a teenager survives a traumatic event—a car accident in which her friends died—and subsequently experiences symptoms of distress, including nightmares about the event and a specific fear of cars. This scenario tests understanding of post-traumatic stress disorder (PTSD), a condition that can develop after an individual experiences a traumatic event.

## **Why the Correct Answer is Right**
The correct answer, **D. Post-Traumatic Stress Disorder (PTSD)**, is appropriate because the girl's symptoms align with the diagnostic criteria for PTSD. These criteria include:
- Exposure to a traumatic event
- Presence of intrusive symptoms (e.g., nightmares about the event)
- Avoidance of stimuli associated with the trauma (e.g., fear of cars)
- Negative alterations in cognition or mood
- Marked alterations in arousal and reactivity

## **Why Each Wrong Option is Incorrect**
- **Option A:** While depression can occur following a traumatic event and may involve sleep disturbances and fear, the specific constellation of symptoms here—nightmares about the event and a new, specific fear of cars—more strongly suggests PTSD.
- **Option B:** Anxiety disorder is a broad category that could encompass some of the girl's symptoms but does not specifically account for the direct response to a traumatic event and the combination of symptoms described.
- **Option C:** Acute stress disorder (ASD) involves similar symptoms to PTSD but occurs in the immediate aftermath of the traumatic event (within days to weeks). The girl's symptoms have persisted after discharge and over a longer period, making PTSD a more appropriate diagnosis.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that PTSD can develop after any traumatic event, not just those typically associated with military service. The disorder's hallmark is a significant and persistent distress or impairment in social, occupational, or other areas of functioning following exposure to a traumatic event. A useful mnemonic to recall some of the PTSD symptoms is "RE-EXPERIENCE, AVOIDANCE, NEGATIVE COGNITION/MOOD, and HYPERAROUSAL."

## **Correct Answer:** D. Post-Traumatic Stress Disorder (PTSD).