Final answer:
The negative symptom of schizophrenia characterized by decreased reactivity to the environment and potential immobility and mutism is called catatonia. It's a part of the motor abnormalities observed in schizophrenia and is treated with antipsychotic medications that impact dopamine neurotransmission.
Step-by-step explanation:
The negative symptom of schizophrenia that is marked by a decrease in reactivity to the environment where individuals may not move or speak for hours or even days is known as catatonia. This condition is characterized by a marked motor abnormalities, including immobility, mutism, and stupor. Neuroleptic drugs that are used to treat psychosis, such as schizophrenia, can lead to similar symptoms but are also known for making patients less agitated and more responsive to the environment over time.
Antipsychotic medications generally block dopamine receptors and reduce dopamine neurotransmission, which can alleviate symptoms like hallucinations, delusions, and disorganized thinking. On the other hand, negative symptoms such as flattened emotional states and loss of pleasure might persist and are more resistant to treatment.