Non-fearful vs. fearful panic attacks: A general population study from the National Comorbidity Survey

Background: Non-fearful panic attacks constitute a subgroup of panic attacks without the experience of subjective fear. However, previous studies were mostly carried out under medical settings and with small samples. The present study aims to clarify and expand the previous findings including the prevalence and characteristics of non-fearful panic attacks by using the National Comorbidity Survey (NCS) database. Methods: From the 8098 original respondents in the NCS, subjects who met the DSM-III-R diagnostic criteria for a lifetime panic attack were selected. Of these, individuals with non-fearful panic attacks were identified and comparisons with subjects with fearful panic attacks were conducted. Results: 30% of panic attacks occur without fears of dying or going crazy. Although these non-fearful panic attacks do not differ from their fearful counterparts in terms of age, age of onset or frequency of attacks, they are less often associated with some symptoms including shortness of breath, trembling, smothering and depersonalization, lead less often to anticipatory anxiety, and lead to less treatment with medication. Although they lead equally to panic disorder diagnosis and cause as much functional impairment, the non-fearful ones are less often associated with diagnoses of agoraphobia, as well as many other Axis I disorders such as major depressive disorder, simple phobia and substance-related disorders. Limitations: Recall bias and response bias may have distorted estimated relationships. Conclusions: Although milder in terms of symptomatology and some comorbidity, clinicians need to pay appropriate attention to non-fearful subtypes of panic attacks which appear to be equally dysfunctional.