The circadian rhythm of blood pressure in patients with panic disorder and generalized anxiety disorder.

Background: Anxiety disorders affect blood pressure both during the day and at night. Little is known about the effect of individual anxiety disorders on the circadian rhythm of blood pressure.

Objectives: The purpose of this study is to compare the nocturnal drop in blood pressure in patients with panic disorder (PD), generalized anxiety disorder (GAD), and healthy individuals.

Methods: The study was conducted on fifty consecutive outpatients with anxiety disorders and personality disorders who participated in intensive group psychotherapy. Diagnoses were made according to DSM-IV-TR criteria using the PSE-10 questionnaire. Out of 50 patients under study, 17 were diagnosed with PD and 21 with GAD. The control group consisted of 40 healthy people recruited in the course of other studies. The resulting three groups were compared in terms of circadian blood pressure using the ABPM method.

Results: Mean nocturnal falls in systolic and diastolic blood pressure were the following: 2% and 3% (PD), 11% and 12% (GAD), 27% and 23% (control). Four people out of PD group had higher systolic and diastolic blood pressure at night than during the day. The ratios between non-dippers/dippers were: 0/15 (PD), 8/21 (38% - GAD) and 40/40 (100% - control).

Conclusions: The patients with PD were characterized by an almost flat course of circadian blood pressure. The patients with GAD had a lower mean nocturnal fall in blood pressure than the control group, but significantly higher than the patients with PD. The differences in the circadian course of blood pressure between PD and GAD are so large that the impact of these disorders should be investigated separately.