Deep TMS May Reduce OCD Symptoms
Obsessive compulsive disorder (OCD) occurs in about 2% of the population worldwide. Selective serotonin reuptake inhibitor (SSRI) antidepressants are the most commonly used treatment for OCD, but not all patients respond adequately to them.
At the 2015 meeting of the Transcranial Magnetic Stimulation Society, researcher Joseph Zohar presented evidence that deep transcranial magnetic stimulation (deep TMS) targeted over the medial prefrontal cortex may reduce OCD symptoms. In TMS treatment, an electromagnetic coil is placed against the patient’s head and magnetic pulses that can penetrate the scalp are converted into small electrical currents that stimulate neurons in the brain. In Zohar’s study, patients with OCD were randomized to receive deep TMS at frequencies of either 20 Hz or 1 Hz, or a sham procedure. The 20 Hz deep TMS resulted in a 28% reduction in OCD symptoms compared to the other two groups, indicating that the 20 Hz treatment had a large effect size.
In addition to the deep TMS procedures, all patients also received cognitive behavioral therapy, high doses of SSRIs, and relapse prevention training.
Editor’s Note: It is interesting that 20 Hz deep TMS, which activates the prefrontal cortex, was more effective than 1 Hz, which decreases activity there. Other attempts to treat OCD have focused on suppressing frontal-striatal-thalamic circuits, which are overactive in the disorder. Since the medial prefrontal cortex is an important area for the new learning required for the extinction of anxiety symptoms in a variety of disorders, increasing activity in this medial prefrontal target area with 20 Hz may activate that extinction process allowing new learning rather than nonspecifically suppressing hyperactive frontal-striatal-thalamic circuits as 1 Hz TMS would do.
Studies of Medications and RTMS in Children Lacking
At the 2015 meeting of the Transcranial Magnetic Stimulation Society in May, researcher Stephanie Ameis discussed the dearth of medication studies in children, particularly for depression but also for schizophrenia and autism spectrum disorders, which share the symptom of impaired executive functioning, which can include skills such as planning and problem solving.
Ameis noted that in a literature review, there were a total of 1046 controlled pharmacological treatment studies in adults compared to only 106 in children, which reflects a relative absence of treatment knowledge, especially for depression (where there were 303 studies in adults versus only 17 in children) and bipolar disorder (where there were 174 studies of adults and 24 of children).
Ameis then reviewed the few studies of rTMS for depression in young people. She identified several series with only a total of 33 children and adolescents who had been treated with rTMS. She is beginning to study rTMS in patients with high-functioning autism (40 patients aged 16 to 25 have been randomized in her study). Ameis also described a 2013 study of rTMS in which patients with schizophrenia showed improved performance on a test of working memory published by Mera S. Barr and colleagues in the journal Biological Psychiatry. Ameis cited this as a rationale for studying rTMS’s effect on cognitive performance in people with autism.
Bloomberg Covers Ketamine as a Depression Treatment
Over the years, we’ve tried to keep readers updated about ketamine‘s use as a fast-acting antidepressant. Bloomberg Business recently covered how the drug is being used by some to treat depression.
