Diurnal panic attacks with and without nocturnal panic attacks:: are there some phenomenological differences?

Objective: To compare nocturnal and diurnal panic attacks in a cross-sectional study and in a longitudinal prospective short-term follow-up. Methods: We selected 57 panic disorder (PD) subjects (DSM-IV) and rated them with the Panic Disorder Severity Scale (PDSS) at baseline and after 30 days of treatment with nortriptyline, and with the Eysenck Personality Inventory and the Brown Attention Deficit Disorder (ADD) Scale at baseline. Results: The sample was divided into a nocturnal and diurnal panic attack (NDPA) group - 57.9% (n = 33) - and a diurnal panic attack (DPA) group - 42.1% (n = 24). The groups showed a similar mean age at onset of PD and a pattern of prominent respiratory symptoms. The PDSS did not differ between the groups following short-term treatment (p = 0.451). There were also neither significant differences in Neuroticism (p = 0.094) and Extroversion (p = 0.269) nor in the Brown ADD Scale (p = 0.527). Conclusion: In our study, patients with both nocturnal and diurnal panic attacks showed similar features in their phenomenology and short-term outcome when compared to pure diurnal panic attacks patients.