Objectives: The frequent comorbidity of panic and affective disorders has been described in previous studies. However, it is not clear how panic disorder comorbidity in unipolar disorder and bipolar disorder is related to illness course.
Methods: We compared lifetime clinical characteristics of illness and items of symptomatology in samples of individuals with bipolar I disorder (n = 290) and unipolar disorder (n = 335) according to the lifetime presence of recurrent panic attacks.
Results: We found significant differences in clinical course of illness characteristics that were shared across the unipolar and bipolar samples according to the lifetime presence of panic attacks. We also found a number of differences according to the presence of panic attacks that may be specific to the diagnostic group.
Conclusions: Distinguishing patients who have mood disorder diagnoses, especially bipolar I disorder, according to the lifetime presence of panic attacks may not only be of use in clinical practice, but may also be informative for aetiological research, such as molecular genetic studies.