**Core Concept**
Psychosis is a state of disconnection from reality, characterized by a disintegration of cognitive processes, including perception, thought, and emotion. This can manifest as hallucinations, delusions, disorganized thinking, and impaired social functioning.

**Why the Correct Answer is Right**
The correct answer, "Preserved contact with reality," is incorrect because psychosis is defined by a loss of contact with reality. Individuals with psychosis often experience a disconnection from their environment, resulting in distorted perceptions and impaired judgment. This is in contrast to individuals with personality disorders, who may exhibit disturbances in thought and behavior but generally maintain a clear and intact sense of reality.

**Why Each Wrong Option is Incorrect**
**Option A:** Loss of insight is actually a feature of psychosis, as individuals may not recognize their own delusions or hallucinations as abnormal. This lack of insight can make treatment more challenging.
**Option B:** Presence of delusions is a hallmark of psychosis, as individuals may hold onto false beliefs despite evidence to the contrary.
**Option D:** Personality disturbances can be a feature of various psychiatric conditions, including personality disorders, which can co-occur with psychosis. However, personality disturbances are not a defining characteristic of psychosis.

**Clinical Pearl / High-Yield Fact**
The presence of delusions or hallucinations in a patient is highly suggestive of a psychotic disorder. It's essential to assess for the presence of these symptoms and to evaluate the patient's level of insight when diagnosing and treating psychosis.

✓ Correct Answer: C. Preserved contact with reality