Recent research has hypothesized an association between traumatic events and nocturnal panic (NP). The purpose of this study was to investigate whether the onset of nocturnal panic attacks is associated with a higher frequency of and/or greater severity of stressful or traumatic life events than that of patients with panic disorders (PDs) who experience daytime panic attacks (DPs) while awake. A secondary aim was to investigate whether NP is associated with specific life events at the onset of the disorder. Our sample comprised 129 subjects with PD (DSM-IV). We investigated the number and types of stressful life events that occurred in the year prior to PD onset using a semistructured interview. Of the sample, 28.7% had recurrent nocturnal panic attacks (NP group). Subjects with and without recurrent NP did not differ on any sociodemographic or clinical characteristic. Neither the number nor type of life event distinguished those with or without NP. The subgroup of patients with PD with recurrent NP appears to represent a variant of PD with a possible increased vulnerability to conditions of diminished arousal as a trigger of panic attacks. However, the hypothesis that this vulnerability might be determined by life events that occur in the period preceding PD onset was not supported by the findings of this study.
