Panic disorder versus panic disorder with major depression; defining and understanding differences in psychiatric morbidity.

The present study examined the impact of comorbid major depressive disorder (MDD) on psychiatric morbidity, panic symptomatology and frequency of other comorbid psychiatric conditions in subjects with panic disorder (PD). Four hundred thirty-seven patients with PD were evaluated at intake as part of a multicenter longitudinal study of anxiety disorders; 113 of these patients were also in an episode of MDD. Patients were diagnosed by DSM-III-R criteria utilizing structured clinical interviews. The 113 PD/MDD patients were compared with the 324 remaining PD subjects regarding panic symptoms at intake, sociodemographic, quality of life and psychiatric morbidity variables. Differences in frequency of other comorbid Axis I psychiatric disorders were assessed at intake; personality disorders were evaluated twelve months after intake. The results revealed the PD/MDD patients exhibit increased morbidity and decreased psychosocial functioning as compared to PD patients. Personality disorders were more prevalent in the PD/MDD group at six month follow-up assessment; the PD/MDD group also had an increased frequency of posttraumatic stress disorder (PTSD) and more comorbid Axis I anxiety disorders as compared to the PD group. The total number and frequency of panic symptoms was highly consistent between the two patient groups.