Which disorder is associated with intense episodes of fear, often occurring without a clear trigger?

Panic disorder is characterized by recurring and unexpected episodes of intense fear or discomfort, known as panic attacks. These episodes can occur suddenly and are often accompanied by physical symptoms such as heart palpitations, shortness of breath, sweating, and feelings of impending doom. This disorder is particularly notable for the fact that these panic attacks can happen without any identifiable trigger, making them particularly distressing for individuals affected by it.

In contrast, generalized anxiety disorder involves a more persistent state of worry about various aspects of life, but the anxiety tends to be more chronic and involves a range of concerns rather than sudden episodes. Obsessive-compulsive disorder is defined by the presence of obsessions (intrusive thoughts) and compulsions (repetitive behaviors) that are performed to relieve anxiety, rather than isolated episodes of fear. Seasonal affective disorder is linked to changes in seasons and usually fluctuates with seasonal light exposure, leading to depressive symptoms rather than acute episodes of fear. Thus, panic disorder is uniquely identified by its episodes of intense fear that appear unexpectedly.