Eleven of 45 normal control subjects experienced panic attacks during
lactate and/or isoproterenol infusions. Ten of the 11 subjects were
followed up for a mean period of 32.5 months. Two subjects reported the
development of spontaneous panic attacks during the follow-up period; one
related the development of these attacks to the infusion experience.
Neither subject met DSM-III criteria for panic disorder either before or
after the infusions. Twenty-six healthy control subjects who did not
experience panic attacks during the infusion experience did not report any
attacks during a follow-up period of 31.1 months.