Comment on 5-HT and mechanisms of defence.

The paper by Deakin and Graeff is a thought-provoking tour-de-force. They propose a comprehensive theory about serotonin (5-hydroxytryptamine; 5-HT) and anxiety, covering much of the same literature which we previously reviewed (Kahn et al., 1988a). We certainly agree that there seems to be an association between 5-HT function and anxiety, but we take issue with several important aspects of Deakin and Graeff's hypothesis. We limit our comments to their discussion of anxiety and panic.