Am J Psychiatry 1991; 148:361-364
Copyright © 1991 by American Psychiatric Association
Nonfearful panic disorder in neurology patients validated by lactate challenge
JL Russell, MG Kushner, BD Beitman and KM Bartels
Psychiatry Department, University of Missouri--Columbia School of Medicine.
OBJECTIVE: Nonfearful panic disorder meets the DSM-III-R criteria for panic
disorder but is not associated with subjective fear and anxiety. The
authors determined its prevalence in a group of neurology patients and
assessed its diagnostic validity as a panic disorder subtype by evaluating
the response of the patients with nonfearful panic disorder to sodium
lactate and antipanic pharmacotherapy. METHOD: The subjects were all
neurology patients referred over 1 year to a university hospital's
psychiatric consultation service because of negative medical workups for
their symptoms (N = 48). Patients who met the DSM-III-R criteria for panic
disorder but did not report subjective anxiety or fear during panic
episodes were diagnosed as having nonfearful panic disorder. Afterward,
each of those patients received a sodium lactate infusion and, 5 hours
later, a sodium chloride infusion. They were then treated with antipanic
medication and followed for at least 6 months. RESULTS: Of the 48 neurology
patients referred for psychiatric evaluation, 11 (23%) met the criteria for
panic disorder, and all 11 met the criteria for nonfearful panic disorder.
All 11 responded positively to lactate but not to placebo, and they each
experienced an at least 75% reduction in symptoms during the 6-month
follow-up period. Detailed case reports of three of these patients are
presented. CONCLUSIONS: These findings support the construct and predictive
diagnostic validity of nonfearful panic disorder as a subtype of panic
disorder and suggest that a lack of attention to this group leads to both
the underestimation of the prevalence of panic disorder and to the
withholding of potentially successful treatments for this group.
