**Core Concept**
Type 1 schizophrenia, also known as the paranoid type, is a subtype of schizophrenia characterized by a predominance of positive symptoms. Positive symptoms include delusions, hallucinations, disorganized thinking, and catatonic behavior.

**Why the Correct Answer is Right**
Negative symptoms, such as poverty of speech, apathy, and social withdrawal, are more commonly associated with type 2 schizophrenia, also known as the disorganized type, or with the residual type of schizophrenia. Type 1 schizophrenia typically presents with a more acute onset and a greater severity of positive symptoms. The presence of negative symptoms in type 1 schizophrenia is less characteristic and may indicate a poorer prognosis.

**Why Each Wrong Option is Incorrect**
**Option A:** Acute illness is a true statement about type 1 schizophrenia, as it often presents with a sudden onset of symptoms.
**Option B:** Good prognosis is also true, as patients with type 1 schizophrenia tend to have a better response to treatment and a more favorable outcome compared to those with type 2 schizophrenia.
**Option D:** Intellect maintained is true, as patients with type 1 schizophrenia typically do not experience significant cognitive impairments.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the presence of negative symptoms in a patient with schizophrenia may indicate a poorer prognosis and a higher likelihood of treatment resistance.

**✓ Correct Answer: C. Negative symptoms**