Phenomenology of panic disorder and major depression in a family study

Family data were used to examine the phenomenology of MDD and panic disorder in relatives with respect to (a) proband diagnoses of PD and MDD, and (b) the occurrence of the disorders comorbidly vs. singly irrespective of family history. PD and MDD do not differ phenomenologically by proband diagnosis. However, PD comorbid with MDD shows more frequent panic attacks and more symptoms than PD without MDD. Endogenous and delusional subtypes and additional comorbidity are more frequent in relatives with MDD plus than in relatives with MDD without PD. The well documented clinical heterogeneities of PD and MDD are not clearly detectable in their phenomenology as a function of whether probands carried both diagnoses or only one. PD and MDD are more severe when they are in the comorbid form compared to when they occur singly.