Anxiety disorders are characterized by which of the following?

Anxiety disorders are primarily characterized by excessive worry and fear. Individuals suffering from these disorders often experience intense anxiety that is disproportionate to the actual situation or threat they are facing. This ongoing worry can be about a variety of concerns, including health, work, social interactions, and daily life events. The intense nature of these fears can significantly impact one's ability to function in daily life, often manifested through physical symptoms such as increased heart rate, sweating, or feeling restless.

In contrast, the other options do not accurately describe anxiety disorders: increased energy and positivity would suggest a state of excitement or a high mood, which is not typical in anxiety disorders; a complete lack of emotions might be associated more with certain mood disorders like depression or dissociation rather than anxiety; immediate reactions without thoughts could imply impulsivity or a lack of self-regulation, which is not a core feature of anxiety disorders, where overthinking and excessive rumination are more common.