The aim of the study is to transfer the rTMS stimulation protocol by Raij et al. (2018) into a therapeutic setting to improve exposure therapy in acrophobic patients. The quasi-randomized, placebo-controlled and double-blinded study will include 88 patients with height phobia (according to DSM 5). All participants will perform two exposure sessions in virtual reality (VR). Before exposure therapy, one group will receive verum rTMS of the left frontal cortex, which is indirectly functionally linked to the ventromedial prefrontal cortex (Raij et al., 2018). The control group will receive sham stimulation. A structural MRI and a TMS navigation system will be used for precise localization of the left FC. Anxiety symptoms will be measured using subjective ratings (e.g. Acrophobia Questionnaire) and the behavioural approach task (BAT) in VR and in real life before and after the treatment, and at 6 months follow-up. Furthermore, blood samples will be collected before rTMS and after exposure treatment to assess epigenetic and gene expression based changes.

The following hypotheses are derived:

1. Patients with acrophobia, who receive an active rTMS of the left FC before VRET, show a significantly stronger reduction of phobic symptoms immediately after exposure therapy, compared to the sham stimulation group.
2. Patients with acrophobia, who receive an active rTMS of the left FC before VRET, show a significantly greater increase in approach behavior and significantly less distress during the BAT immediately after exposure therapy, compared to the sham stimulation group.
3. The postulated differences in hypotheses 1 and 2 are still detectable at follow-up after 6 months.

Inclusion Criteria:

• Acrophobia (according to DSM-5)
• Right handed
• German native speaker
• Written informed consent

Exclusion Criteria:

• Neurological and/or severe physical illnesses
• Comorbid Axis I disorder (other than phobias)
• Pretreated phobia of heights
• Use of tricyclic antidepressants, antipsychotics, or other substances that increase cerebral seizure susceptibility
• Craniocerebral injuries, head surgery
• Epileptic seizures, or family history of epilepsy
• Metal parts in the head area
• Cardiac pacemakers
• Infusion pumps
• Heart diseases
• Increased intracranial pressure
• Pregnancy
• Cochlear implants
• Tattoos (done before the year 2000)
• Piercings (if not completely removable)
• Permanent make-up
• Nicotine or pain patches
• other MRI contraindications