ERP N1 as a Treatment Predictor of Generalized Anxiety Disorder (N1)

The Amplitude Change of the Auditory Evoked N1 Component as a Predictor of Response to Escitalopram Treatment in Patients With Generalized Anxiety Disorder

Amplitude changes of the N1 and the N1/P2 ERP component in response to different tone intensities have been suggested as a correlative of central serotonergic activity. A strong loudness dependence amplitude increase (strong intensity dependence) reflects low serotonergic neurotransmission and vice versa. Many researchers assumed that the brain serotonergic activity could influence treatment response of highly selective serotonin reuptake inhibitors in depression and anxiety disorders. There are a couple of studies reporting associations of N1 amplitude intensity dependence with response to Citalopram (positive correlation) and Reboxetine (negative correlation) treatment in major depressive disorder patients. But so far there have been no reports about associations between ERP N1 and antidepressant response in GAD patients. So, it would be very interesting to explore the correlations between ERP N1 amplitude change and the Escitalopram treatment responsiveness in GAD patients.

Start with escitalopram 10mg According to patient's symptoms, stay on 10mg or increase up to 20mg Concomitant therapy : up to Xanax 0.5mg, or Ativan 1mg, not allowed above these dosages Length of washout period will be at least 2 weeks for any psychotropic drugs

Inclusion Criteria: DSM-IV TR for GAD Hamilton Rating Scale for Anxiety (HAMA) >18 18 to 75 years old Exclusion Criteria: Severe medical illness Other psychiatric illness HAMD > 18 High suicidal risk pregnancy

Linka T, Muller BW, Bender S, Sartory G, Gastpar M. The intensity dependence of auditory evoked ERP components predicts responsiveness to reboxetine treatment in major depression. Pharmacopsychiatry. 2005 May;38(3):139-43. doi: 10.1055/s-2005-864126.

Linka T, Sartory G, Bender S, Gastpar M, Muller BW. The intensity dependence of auditory ERP components in unmedicated patients with major depression and healthy controls. An analysis of group differences. J Affect Disord. 2007 Nov;103(1-3):139-45. doi: 10.1016/j.jad.2007.01.018. Epub 2007 Feb 20.

Linka T, Muller BW, Bender S, Sartory G. The intensity dependence of the auditory evoked N1 component as a predictor of response to Citalopram treatment in patients with major depression. Neurosci Lett. 2004 Sep 9;367(3):375-8. doi: 10.1016/j.neulet.2004.06.038.