neuroticism

This term is primarily used within the field of psychology, specifically as one of the Big Five personality traits. It describes a stable disposition toward emotional reactivity rather than a clinical diagnosis of neurosis. While it can be used in casual conversation to describe someone who is "high-strung," in a technical context, it refers to the degree to which an individual is prone to psychological distress.

As an abstract noun representing a psychological construct or trait, it is uncountable. It does not have a plural form and is typically modified by adjectives such as "high," "low," or "moderate" to indicate the level of the trait present in a person.