Diurnal rhythms and symptom severity in panic disorder. A preliminary study of 24-hour changes in panic attacks, generalised anxiety, and avoidance behaviour.

Diurnal changes in the frequency of panic attacks and symptoms of generalised anxiety, phobic anxiety and phobic avoidance in 34 panic-disorder patients and 40 normal controls were evaluated. The panic-disorder patients had significant diurnal changes in generalised and phobic anxiety, but not phobic avoidance. Increased severity of symptoms and prominent diurnal changes were most evident in the panic-disorder patients with a history of depression. Although panic attacks were distributed throughout the 24-hour period, patients with a current episode or history of depression tended to have more frequent panic attacks in the morning or early afternoon. These observations challenge the traditional belief that 'anxious neurotic' patients are relatively asymptomatic upon awakening in the morning and then develop more severe symptoms of anxiety later in the day.