**Core Concept**
Schizophrenia is a chronic and severe mental disorder characterized by disruptions in thought processes, perceptions, emotional responsiveness, and social interactions. Identifying prognostic factors is crucial for predicting treatment outcomes and providing appropriate care.

**Why the Correct Answer is Right**
The presence of negative symptoms, such as apathy, social withdrawal, and lack of emotion, is a well-established bad prognostic factor for schizophrenia. Negative symptoms are thought to be associated with a poorer response to treatment and a higher risk of relapse. This is because negative symptoms are often resistant to antipsychotic medication and may require additional interventions, such as cognitive-behavioral therapy or social skills training.

**Why Each Wrong Option is Incorrect**
* **Option A:** **First-rank symptoms** (e.g., hearing voices, seeing visions) are actually good prognostic factors for schizophrenia. They are often associated with a better response to antipsychotic medication and a lower risk of relapse.
* **Option B:** **Family history** of schizophrenia can be a risk factor for developing the disorder, but it is not a bad prognostic factor for treatment outcomes.
* **Option C:** **Age of onset** (early vs. late) can influence treatment outcomes, but it is not the most significant bad prognostic factor for schizophrenia.

**Clinical Pearl / High-Yield Fact**
Negative symptoms in schizophrenia can be subtle and difficult to recognize, making it essential for clinicians to use standardized assessment tools, such as the Positive and Negative Syndrome Scale (PANSS), to accurately diagnose and monitor treatment response.

**Correct Answer:** C.