What is the term for a psychological disorder characterized by a lack of emotional response?

The term that describes a psychological disorder characterized by a lack of emotional response is "flat affect." This phenomenon refers specifically to a significantly diminished emotional expression or a lack of emotional reactivity, where an individual may display minimal facial expressions or limited vocal inflection, which can make them appear emotionally unresponsive even in situations typically eliciting strong feelings.

Flat affect is often associated with various mental health conditions, particularly schizophrenia and severe mood disorders. It highlights the disconnect between internal emotional states and outward emotional expression, which can lead to misunderstandings in social interactions.

In contrast, other options, such as depression, often involve significant emotional experiences, albeit sometimes in a negative context. Social anxiety is characterized by fear of social situations, which can lead to avoidance behavior rather than a lack of emotional response. Schizophrenia, while it may include flat affect as a symptom, encompasses a broader range of symptoms, such as delusions and hallucinations, which are not solely defined by a lack of emotional expression.