Active or sham TNS treatment will be performed at the patients' home for approximately 8 hours per night 7 days a week for 8 consecutive weeks.

Trigeminal nerve stimulation will occur by placement of electrodes (1.25" silver electrodes Bio-Flex BF4, Biotens/Vermed, Buffalo, NY, USA) bilaterally on the V1 branches of the trigeminal nerve (CNV) located on the forehead. Current will be generated from the EMS 7500 stimulator (TENS Products, Inc., Granby, CO) (Class II medical device) and will be set to a level that is clearly perceptible by each patient (i.e. tingling sensation) but not uncomfortable or painful. Current level will be determined for each patient at baseline and will likely be between 4-6 mA. Active stimulation will occur at 120 Hz with a 250 µs pulse width and with a duty cycle of 30 seconds on to 30 seconds off.

Active or sham TNS treatment will be performed at the patients' home for approximately 8 hours per night 7 days a week for 8 consecutive weeks.

Sham stimulation will occur by placement of electrodes (1.25" silver electrodes Bio-Flex BF4, Biotens/Vermed, Buffalo, NY, USA) bilaterally on the V1 branches of the trigeminal nerve (CNV) located on the forehead. Current will be generated from the EMS 7500 stimulator (TENS Products, Inc., Granby, CO) (Class II medical device) and will be set to a level that is clearly perceptible by each patient (i.e. tingling sensation) but not uncomfortable or painful. Current level will be determined for each patient at baseline and will likely be between 4-6 mA. Sham stimulation will use the same parameters of active stimulation, but after 60 seconds the stimulator will turn off.

Active trigeminal nerve stimulation

Treatment response will be defined as a score of 1 or 2 on the Clinical Global Impression - Improvement scale (CGI-I). CGI-I scores range from 0 to 7. Zero corresponds to "not assessed". Low scores correspond to improvement, high scores correspond to worsening.

Remission will be defined as a score of 1 or 2 on the Clinical Global Impression - Severity scale (CGI-S). CGI-S scores range from 0 to 7. Zero corresponds to "not assessed". Low scores correspond to mild and high scores correspond to severe.

Improvement of generalized anxiety disorder symptoms measured with the Generalized Anxiety Disorder 7-item scale (GAD-7). Scores go from 0 (no generalized anxiety symptoms) to 21 (severe generalized anxiety symptoms).