tDCS and Psychotherapy for the Treatment of Anxiety Disorders (tDCSplusUP)

The Efficacy of Transcranial Direct Current Stimulation Combined With the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders: a Double Blind, Sham Controlled, Randomized Factorial Designed Study for Anxiety Disorders

The main goal of the study is to test the efficacy of tDCS in combination with the Unified Protocol for transdiagnostic treatment of emotional disorders, to reduce anxiety symptoms in a mixed anxiety disorders sample, as assessed by the Hamilton Anxiety Rating Scale (HARS; Hamilton, 1959).

Participants will be randomly allocated to one of four parallel experimental arms, within a 2X2 factorial design in which two interventions (tDCS and CBT-UP) will be delivered, and assessed according to two levels (e.g., intervention vs. no intervention). Each study participant will assigned to one factor level. Four intervention groups are defined active tDCS + CBT-UP sham tDCS + CBT-UP active tDCS + Psychoeducation sham tDCS + Psychoeducation The four arms allow to experimentally control the two active therapeutic interventions: active tDCS and CBT-UP. Sham tDCS is the control for active tDCS and psychoeducation is the control condition for CBT-UP. The intervention will last for 15 weeks, and all groups will comply with the same intervention structure according to the examination plan established in the protocol: week 1-2: 1 CBT-UP session/week week 3-4: 5 tDCS sessions and 1 CBT-UP session/week week 5-8: 2 tDCS sessions and 1 CBT-UP session/week week 9-14: 1 tDCS session and 1 CBT-UP session/week week 15: 1 CBT-UP session The treatment will consist of 26 transcranial direct current stimulation sessions, each lasting 20 minutes, with a current intensity of 2 mA, the cathode placed over the right dorsolateral prefrontal cortex and the anode placed over the left deltoid muscle. tDCS will be combined with cognitive-behavioral therapy, in particular following the unified protocol for transdiagnostic treatment of emotional disorders (Barlow et al. 2018). Safety: No serious adverse effects are expected with conventional tDCS protocols in humans (≤40 min, ≤4 mA; conclusions from a meta-analysis observing >33200 sessions, >1000 subjects with repeated sessions; Bikson et al., 2016). Plans for treatment or care after the subject has ended his/her participation in the trial: Patients will be recommended and offered the best treatment as evidenced by the trial results. For patients that already completed that intervention further standard psychological/psychiatric treatment will be recommended according to patients' status.

Sham tDCS (control for active tDCS) combined with the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders.

26 transcranial direct current stimulation sessions, each lasting 20 minutes, with a current intensity of 2 mA, the cathode placed over the right dorsolateral prefrontal cortex and the anode placed over the left deltoid muscle.

15 psychotherapy sessions (1/week) following the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders developed by Barlow et al. 2018.

The mean change in the Hamilton Anxiety Rating Scale (HARS; Hamilton, 1959) score, from baseline. HARS total score ranges from 0 to 56, where higher values indicate higher anxiety symptom's severity.

Defined as reduction of total Hamilton Anxiety Rating Scale (HARS; Hamilton, 1959) to scores lower than 18 (indicating mild anxiety severity).

The mean change in the Hamilton Depression Rating Scale (HRSD; Hamilton, 1960) score, from baseline. HDRS total score ranges from 0 to 75, where higher values indicate higher depressive symptoms' severity.

Inclusion Criteria: Diagnosis of generalized anxiety disorder, specific phobia, panic disorder, agoraphobia, or social anxiety disorder. Willing to participate and to give written informed consent Exclusion Criteria: Contra-indications to tDCS use: Presence of a cardiac or neurological condition Metallic implants If contact with scalp is not possible Have had a head injury resulting in a loss of consciousness that has required further investigation History of seizures Epilepsy or a history of epilepsy Past adverse effects with non-invasive stimulation treatments Current diagnosis of another psychiatric disorder (except for depression, as long as secondary diagnosis), psychoactive medication or psychological treatment Left-handedness Pregnancy Skin condition on the stimulation target area Recreational drug use

HAMILTON M. The assessment of anxiety states by rating. Br J Med Psychol. 1959;32(1):50-5. doi: 10.1111/j.2044-8341.1959.tb00467.x. No abstract available.

HAMILTON M. A rating scale for depression. J Neurol Neurosurg Psychiatry. 1960 Feb;23(1):56-62. doi: 10.1136/jnnp.23.1.56. No abstract available.

Bikson M, Grossman P, Thomas C, Zannou AL, Jiang J, Adnan T, Mourdoukoutas AP, Kronberg G, Truong D, Boggio P, Brunoni AR, Charvet L, Fregni F, Fritsch B, Gillick B, Hamilton RH, Hampstead BM, Jankord R, Kirton A, Knotkova H, Liebetanz D, Liu A, Loo C, Nitsche MA, Reis J, Richardson JD, Rotenberg A, Turkeltaub PE, Woods AJ. Safety of Transcranial Direct Current Stimulation: Evidence Based Update 2016. Brain Stimul. 2016 Sep-Oct;9(5):641-661. doi: 10.1016/j.brs.2016.06.004. Epub 2016 Jun 15.

Barlow DH, Farchione TJ, Bullis JR, Gallagher MW, Murray-Latin H, Sauer-Zavala S, Bentley KH, Thompson-Hollands J, Conklin LR, Boswell JF, Ametaj A, Carl JR, Boettcher HT, Cassiello-Robbins C. The Unified Protocol for Transdiagnostic Treatment of Emotional Disorders Compared With Diagnosis-Specific Protocols for Anxiety Disorders: A Randomized Clinical Trial. JAMA Psychiatry. 2017 Sep 1;74(9):875-884. doi: 10.1001/jamapsychiatry.2017.2164.