The main characteristics of generalized anxiety disorder (GAD) are chronic pathological worry, other manifestations of nonphobic anxiety, and various symptoms of tension. Physical symptoms of anxiety are usually less prominent in GAD than in panic disorder, but they can still be an important component of clinical presentation. Behaviors that are often seen in other anxiety disorders, such as overt avoidance, are conspicuously absent. Unlike all other anxiety disorders, it is more likely for GAD in clinical setting to co-occur with a primary condition for which help has been sought–usually depression or other anxiety disorder–than to be the main reason for seeking professional help. Generalized anxiety disorder is one of the more controversial members of the family of anxiety disorders: it seems that almost every aspect of GAD has provoked debates that do not show signs of abating. Paradox, disagreement, debate, and controversy are the words most commonly associated with GAD. It is small wonder then that the list of ‘‘hot topics’’ related to GAD could be very long indeed. Listed below is a selection of issues thought to represent adequately a more comprehensive list…. 1. What are the characteristic features of GAD that would help in its conceptualization? Pathological worry, other cognitive aspects of anxiety, manifestations of tension, and/or (some) symptoms of autonomic arousal? What combination of these features would ensure that GAD is diagnosed adequately and recognized in clinical practice? 2. What is the relationship between pathological worry and GAD? 3. How can different views on what constitutes the essence of GAD be reconciled? Is GAD a single entity or are there two or more ‘‘types’’ of GAD with distinct clinical characteristics? 4. How is GAD related to depressive disorders, other anxiety disorders, and personality disturbance? Where are its boundaries? In view of its close relationship with depression, should GAD be classified along with depression and perhaps renamed accordingly? 5. Can GAD exist on its own, without depression or other anxiety disorders? What could be features specific enough for GAD that would allow it to establish itself as an independent and valid psychopathological and diagnostic entity? 6. What are the pathophysiological correlates of pathological worry and other aspects of chronic anxiety in GAD? 7. What are the underlying mechanisms and purpose of pathological worry in GAD? What is the meaning of chronic anxiety?