Using TMS to address the cognitive symptoms of schizophrenia

Five sessions of transcranial magnetic stimulation (TMS) improved processing speed in people with schizophrenia, and the improvement was related to changes in default mode network activity, according to a recent study published in Molecular Biology.

Heather Burrell Ward, M.D., corresponding author and the Director of Neuromodulation Research at Vanderbilt Health, recently sat down with Managed Healthcare Executive to discuss the results.

The default mode network is a brain network that must be suppressed when a person is working on a cognitive task. Ward said people with schizophrenia do not suppress it as well as they should, which hurts cognitive performance. To test the effects of TMS on cognitive symptoms, Ward and her team placed the TMS coil over the parietal cortex, a region within the network, and applied an inhibitory stimulation pattern intended to down-regulate it.

In the first study, participants received a single session that lasted about a minute. It did not change cognitive performance. Ward said that result was not surprising, because treatment of depression typically takes 20 or more sessions to produce a durable effect. In the second study, the team scaled up to five sessions and saw improvement in processing speed, one of the cognitive domains most severely affected in schizophrenia.

The work targets a gap in care. Cognitive deficits are often the leading cause of disability and poor functional outcome in schizophrenia, Ward said, and current medications do little to treat them. Sometimes, current medications even exacerbate symptoms. Difficulty with attention and concentration can keep people from returning to school or work even when hallucinations are controlled.