Sympathetic activation in broadly defined generalized anxiety disorder

Area of Science:

• Psychiatry
• Clinical Psychology
• Psychophysiology

Background:

• Diagnostic criteria for generalized anxiety disorder (GAD) have evolved, narrowing focus to worry and reducing emphasis on somatic symptoms.
• This shift may exclude individuals with chronic anxiety and physiological hyperarousal from diagnosis and treatment.

Purpose of the Study:

• To investigate the clinical characteristics of chronically anxious patients.
• To determine if these patients exhibit physiological signs of sympathetic activation.
• To compare broadly defined anxious patients with a calm control group.

Main Methods:

• Participants were recruited based on chief complaints of tension or self-described calmness.
• Structured interviews and questionnaires were administered.
• 24-hour ambulatory monitoring of finger skin conductance, motor activity, and ambient temperature was conducted.

Main Results:

• The tense group showed shorter periods of skin conductance level (SCL) declines during waking and sleep.
• During waking hours, the tense group exhibited higher minute-by-minute SCL distributions, despite similar overall mean SCL.
• These findings indicate a reduced capacity to lower sympathetic tone in the tense group.

Conclusions:

• Broader definitions of GAD may encompass chronically anxious and hyperaroused individuals not meeting current diagnostic standards.
• These patients demonstrate physiological evidence of sympathetic overactivity, suggesting a need for clinical and research attention.
• Failure to periodically reduce sympathetic tone may be a key characteristic of this under-recognized group.