Sleep in nondepressed patients with panic disorder: I. Systematic assessment of subjective sleep quality and sleep disturbance.

To systematically assess sleep complaints in panic disorder (PD), the Pittsburgh Sleep Quality Index (PSQI) was administered to 34 untreated patients with DSM-III-R PD and 34 age-matched healthy controls (HC). PD patients reported significantly more impaired sleep than HC as indicated by higher global index scores on the PSQI (6.9 +/- 2.9 versus 3.1 +/- 2.0; p < 0.0001) and on four of seven of its subscales; sleep was worst among those PD patients with a prior history of major depression. Sixty-eight percent of patients with PD reported moderately or severely impaired sleep compared to only 15% of HC (chi 2 = 17.5, p < 0.0005). Twenty-six percent of PD patients--but none of the HC--complained of frequent awakenings in the preceding month because they "could not breathe comfortably" (Fisher's exact test, p < 0.00625). One-month prevalence of sleep panic in the patients was 18%; lifetime prevalence was 68%. Whereas these findings confirm previous reports of frequent sleep complaints in patients with PD, they also raise the possibility that some of the findings might be trait phenomena attributable to a history of mood disorder.