• anxiety disorder;
  • psychophysiology;
  • electrodermal activity;
  • habituation;
  • galvanic skin resistance

Forty anxiety patients diagnosed according to DSM-III-R criteria were included: panic disorder (n= 12), agoraphobia (n= 11), generalized anxiety disorder (n= 9), anxiety disorder not otherwise specified (n= 8) and compared with 12 controls. Millon Clinical Multiaxial Inventory and Symptom Checklist-90R symptom and personality scales did not separate the diagnostic groups. Electrodermal activity showed delayed habituation and high spontaneous skin resistance fluctuations in the panic and agoraphobia groups compared with the non-panic groups. The generalized anxiety disorder patients could not be separated from the controls, and the anxiety disorder not otherwise specified patients showed less electrodermal activity than the controls on most variables. In contrast to self-report instruments, electrodermal activity discriminated between diagnostic groups of patients with DSM-III-R anxiety disorders, more specifically between patients with and without panic attacks.