Which term refers to a mental disorder characterized by delusions and perceived hostility from others?

The term that refers to a mental disorder characterized by delusions and perceived hostility from others is paranoia. Paranoia is often associated with a pervasive and irrational mistrust or suspicion of others, leading individuals to believe they are being targeted or discriminated against without sufficient evidence. This condition can manifest through various symptoms, including the belief that people are out to harm or deceive them, which contributes to the overall sense of unease and anxiety in affected individuals.

The other options present alternative concepts that do not align with the definition provided in the question. For example, the null effect refers to a statistical result where a variable does not produce any significant change in another variable. Similarly, the parasympathetic nerve is part of the autonomic nervous system responsible for rest-and-digest activities, and parasympathomimetic drugs are substances that mimic the action of the parasympathetic nervous system. None of these terms pertain to the characteristics of delusions and perceived hostility central to paranoia.