Tolerability and Safety of 30 Intensified Transcranial Direct Current Stimulation (tDCS) Sessions in Entomophobia Treatment

Background: Entomophobia is a frequent specific phobia characterized by intense, persistent, and intense fear of insects. Recently, the effectiveness of noninvasive brain stimulation (NIBS) techniques, such as transcranial direct current stimulation (tDCS), has been shown in psychiatric disorders. Here, a new, intensified protocol has been developed, which ich suggested to induce late-phase long-term potentiation (LTP)-like plasticity, and increases efficacy of the intervention. Methods: In the present case report, we evaluated the effectiveness of a new intensified tDCS protocol (30 sessions, 2 mA for 20 min, 2 sessions daily with 20 min interval between daily sessions, for 15 days) applied to the left ventromedial prefrontal cortex (AF3 according to EEG International 10-20 system), which is suggested to induce late phase plasticity, and therefore is expected to have superior clinical effects, in a girl with severe cockroach phobia. Severity of phobia symptoms, the anxiety level to phobic stmuli (cockroach), general anxity, depression and emotional distress were measured before and immediately after intervention and for follow-up (3 weeks and 6 weeks after the last intervention). Results: The results show a significant improvement of phobia symptoms post intervention for up to 6 weeks after the last intervention, and side effects, including burning sensations and skin redness, were mild. These findings suggest that an intensified tDCS stimulation protocol over the left vmPFC may effectively improve phobia symptoms. Conclusions: Moreover, the results showed that this intensified protocol is safe and tolerable. In order to substantiate the effects of the current protocol, further investigations in larger patient groups are required.