## **Core Concept**
Post-Traumatic Stress Disorder (PTSD) is a psychiatric condition that can occur in individuals who have experienced or witnessed a traumatic event. The diagnosis of PTSD involves a set of symptoms that last for more than a month and cause significant distress or impairment in social, occupational, or other important areas of functioning. The timing of symptom onset is crucial for the diagnosis of PTSD.

## **Why the Correct Answer is Right**
The correct answer, , indicates that delayed onset PTSD is diagnosed if symptoms appear after 6 months. According to the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition), PTSD can have a delayed onset, where the symptoms may not appear until months or even years after the traumatic event. This criterion helps differentiate between acute stress disorder (ASD), which has a symptom duration of 3 days to 1 month, and PTSD.

## **Why Each Wrong Option is Incorrect**
* **Option A:** This option suggests 1 month, which is actually the timeframe for acute stress disorder (ASD), not delayed onset PTSD.
* **Option B:** This option suggests 3 months, which, although close, does not align with the DSM-5 criteria for delayed onset PTSD.
* **Option D:** This option suggests 12 months, which exceeds the timeframe specified for delayed onset PTSD.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that for a diagnosis of PTSD, the symptoms must last more than 1 month and cause significant distress or impairment. Additionally, the delayed onset specifier is used when the full symptom profile is not met until at least 6 months after the event.

## **Correct Answer:** . 6 months.