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

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 is suggested to induce late-phase long-term potentiation (LTP)-like plasticity, and increase efficacy of the intervention. 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 a 20 min interval between daily sessions, for 15 d) applied to the left ventromedial prefrontal cortex (AF3 according to the EEG International 10 to 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 stimuli (cockroach), general anxiety, depression, and emotional distress were measured before and immediately after intervention and at follow-up (3 wk and 6 wk after the last intervention). The results show a significant improvement in phobia symptoms postintervention, maintained 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. Moreover, the results showed that this intensified protocol is safe and tolerable. To substantiate the effects of the current protocol, further investigations in larger patient groups are required.