Effects of repetitive transcranial magnetic stimulation as a treatment for persistent auditory verbal hallucinations

Abstract

Auditory verbal hallucinations (AVHs) are perception-like experiences that occur without an external stimulus. Phenomenological studies suggest that AVHs can vary along eight dimensions: loudness, clarity, complexity, frequency, control, location, content and personification. AVHs are experienced by 70% of patients with schizophrenia and can cause high levels of stress and functional debility. Atypical antipsychotic drugs are the recommended treatment for AVHs but are non-effective in 25-30% of cases. Cognitive behavioral therapy (CBT) has proven reasonably effective but improvements can still be made to the treatment for some patients that experience AVHs. Transcranial Magnetic Stimulation (TMS) is a non-invasive brain stimulation that can inhibit cortical activity in brain regions shown to be hyperactive during AVHs. We studied the effectiveness of repetitive TMS (rTMS) as a treatment for persistent AVHs. The hypotheses were that TMS could reduce 1) AVH, 2) depression, anxiety and stress, and 3) increase quality of life. A total of 6 patients diagnosed with primary psychotic disorder that were seeking services at the University Hospital of Iceland were randomized to either active (n=2) or sham (n=4) rTMS treatment. AVHs, depression, anxiety, stress and quality of life were assessed before and after treatment and at a one and three month’s follow-up. Active rTMS significantly reduced frequency and duration of AVH compared to the sham group. RTMS treatment did not show statistically significant effects on depression, anxiety, stress or quality of life. These results indicate that rTMS can be an effective treatment for AVH.