[Experimental possibilities of biological provocation of panic attacks].

On the point of anxiety states, behavioural sciences have only recently been provided with sufficient operational definitions of clinical concepts to enable us to start working on the construction of valid models for the different disorders. Panic attacks are defined as attacks manifested by discrete periods of apprehension or fear, concomitant with at least four marked vegetative sensations, as described in the DSM-III. Several interventions have proved to be able to mimic experimentally such episodes in vulnerable patients, providing the researcher with valuable models for panic research such as the lactate infusion technique, the single CO2 inhalation model and, to a lesser extent, the hyperventilation provocationtest. The study of these models may be a major contribution to a better understanding of panic anxiety, both from a biological and behavioural point of view. Biological observations of those models point to pH changes and ionic shifts as a physiological concomitant in the genesis of experimentally induced panic, and suggests that hypersensitive chemoreceptive structures of the CNS may be implicated. As to the behavioural aspects of the models, there is strong evidence for the ancient phobophobia, or "fear of fear" idea, which may explain the invaldating recurrence of panic attacks.