Our purpose in this study was to compare the prevalence and pattern of Axis I and II comorbidities between patients with and without nocturnal panic (NP) attacks. One hundred and sixteen subjects with panic disorder (PD; according to DSM-IV criteria) were included: We assessed Axis I and II comorbidities using the Structured Clinical Interview for DSM-IV Axis I and II disorders, respectively. Of the sample, 27.6% of subjects had recurrent nocturnal panic attacks (NP group). Subjects with NP did not differ from those without in any sociodemographic or clinical characteristics. In the sample (94 subjects), 81% had at least one lifetime comorbid Axis I disorder, without significant differences between subjects with and without nocturnal panic even when considering comorbidity rates for single disorders; a trend toward significance was found for anorexia nervosa and somatization disorder, which both were more frequent among subjects with NP. Concerning Axis II disorders, 49.1% of the sample (57 subjects) met the criteria for at least one personality disorder, without significant differences between patients with and without NP. No significant differences were detected in comorbidity rates for any single Axis II personality disorder. Personality might play a relevant role in influencing treatment approaches to PD, but it does not appear to be a differential focus of concern in patients with compared to those without NP.
