**Core Concept**
The DSM IV criterion for depression involves a set of specific clinical features and symptoms that define a depressive episode. This criterion is essential for diagnosing major depressive disorder (MDD) and differentiating it from other psychiatric conditions.

**Why the Correct Answer is Right**
The DSM IV criterion for depression requires a minimum of five symptoms, which must include either depressed mood or loss of interest in activities, and at least one of the following: significant weight loss, insomnia or hypersomnia, psychomotor agitation or retardation, fatigue or loss of energy, feelings of worthlessness or guilt, recurrent thoughts of death. This criterion assesses the presence and severity of depressive symptoms, which are essential for diagnosing MDD.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not a correct criterion for depression in the DSM IV.
* **Option B:** This option is not a specific criterion for depression in the DSM IV.
* **Option D:** This option does not accurately describe the DSM IV criterion for depression.

**Clinical Pearl / High-Yield Fact**
Remember that the DSM IV criterion for depression requires a minimum of five symptoms, which must include either depressed mood or loss of interest in activities. This criterion is essential for differentiating MDD from other psychiatric conditions.

**Correct Answer:** C. Five symptoms, including depressed mood or loss of interest in activities, and at least one of the following: significant weight loss, insomnia or hypersomnia, psychomotor agitation or retardation, fatigue or loss of energy, feelings of worthlessness or guilt, recurrent thoughts of death.