Selectively rewiring the brain's circuitry to treat depression

September 30, 2014, Elsevier
Credit: George Hodan/Public Domain

On Star Trek, it is easy to take for granted the incredible ability of futuristic doctors to wave small devices over the heads of both humans and aliens, diagnose their problems through evaluating changes in brain activity or chemistry, and then treat behavior problems by selectively stimulating relevant brain circuits.

While that day is a long way off, transcranial magnetic stimulation (TMS) of the left does treat symptoms of depression in humans by placing a relatively small device on a person's scalp and stimulating . However, relatively little is known about how, exactly, TMS produces these beneficial effects.

Some studies have suggested that TMS may modulate atypical interactions between two large-scale neuronal networks, the frontoparietal central executive network (CEN) and the medial prefrontal-medial parietal default mode network (DMN). These two functional networks play important roles in emotion regulation and cognition.

In order to advance our understanding of the underlying antidepressant mechanisms of TMS, Drs. Conor Liston, Marc Dubin, and their colleagues conducted a longitudinal study to test this hypothesis.

The researchers used functional magnetic resonance imaging in 17 currently depressed patients to measure connectivity in the CEN and DMN networks both before and after a 25-day course of TMS. They also compared the connectivity in the depressed patients with a group of 35 healthy volunteers.

TMS normalized depression-related hyperconnectivity between the subgenual cingulate and medial prefrontal areas of the DMN, but did not alter connectivity in the CEN.

Liston, an Assistant Professor at Weill Cornell Medical College, further details their findings, "We found that connectivity within the DMN and between nodes of the DMN and CEN was elevated in depressed individuals compared to healthy volunteers at baseline and normalized after TMS. Additionally, individuals with greater baseline connectivity with subgenual anterior cingulate cortex – an important target for other antidepressant modalities – were more likely to respond to TMS."

These findings indicate that TMS may act, in part, by selectively regulating network-level connectivity.

Dr. John Krystal, Editor of Biological Psychiatry, comments, "We are a long way from Star Trek, but even the current ability to link brain stimulation treatments for depression to the activity of particular brain circuits strikes me as incredible progress."

Dubin, also an Assistant Professor at Weill Cornell Medical College, adds, "Our findings may inform future efforts to develop personalized strategies for treating depression with TMS based on the connectivity of an individual's . Further, they may help triage to TMS only those patients most likely to respond."

Explore further: Insulin increases resting-state functional connectivity in T2DM

More information: The article is "Default Mode Network Mechanisms of Transcranial Magnetic Stimulation in Depression" by Conor Liston, Ashley C. Chen, Benjamin D. Zebley, Andrew T. Drysdale, Rebecca Gordon, Bruce Leuchter, Henning U. Voss, B.J. Casey, Amit Etkin, and Marc J. Dubin (DOI: 10.1016/j.biopsych.2014. 01.023). The article appears in Biological Psychiatry, Volume 76, Issue 7 (October 1, 2014)

Related Stories

Insulin increases resting-state functional connectivity in T2DM

September 30, 2014
(HealthDay)—For older adults with type 2 diabetes, a single dose of intranasal insulin increases resting-state brain functional connectivity, according to a study published online Sept. 23 in Diabetes.

Activity in brain networks related to features of depression

April 3, 2012
Depressed individuals with a tendency to ruminate on negative thoughts, i.e. to repeatedly think about particular negative thoughts or memories, show different patterns of brain network activation compared to healthy individuals, ...

Low strength brain stimulation may be effective for depression

July 22, 2014
Brain stimulation treatments, like electroconvulsive therapy (ECT) and transcranial magnetic stimulation (TMS), are often effective for the treatment of depression. Like antidepressant medications, however, they typically ...

Visualising plastic changes to the brain

September 4, 2014
Tinnitus, migraine, epilepsy, depression, schizophrenia, Alzheimer's: all these are examples of diseases with neurological causes, the treatment and study of which is more and more frequently being carried out by means of ...

Imaging the magnetically stimulated brain

November 19, 2013
(Medical Xpress)—MRI scanners have steadily increased in power, giving researchers ever finer-grained snapshots of the brain in action. However just as modern day fighters can pull high G turns that would drain consciousness ...

Study reveals new clues to help understand brain stimulation

September 29, 2014
Over the past several decades, brain stimulation has become an increasingly important treatment option for a number of psychiatric and neurological conditions.

Recommended for you

Study reveals cannabinoid drugs make pain feel 'less unpleasant, more tolerable'

September 19, 2018
Researchers in the College of Arts and Sciences have determined that cannabinoid drugs do not appear to reduce the intensity of experimental pain, but, instead, may make pain feel less unpleasant and more tolerable.

Mindfulness meditation: 10 minutes a day improves cognitive function

September 19, 2018
Practising mindfulness meditation for 10 minutes a day improves concentration and the ability to keep information active in one's mind, a function known as "working memory". The brain achieves this by becoming more efficient, ...

The 'real you' is a myth – we constantly create false memories to achieve the identity we want

September 19, 2018
We all want other people to "get us" and appreciate us for who we really are. In striving to achieve such relationships, we typically assume that there is a "real me". But how do we actually know who we are? It may seem simple ...

Close intercultural romantic relationships and friendships can boost creativity

September 19, 2018
You've worked abroad. You've lived abroad. But have you had a close friendship or romantic relationship with a person from a culture drastically different from your own?

New research helps to instill persistence in children

September 19, 2018
Encouraging children "to help," rather than asking them to "be helpers," can instill persistence as they work to fulfill daily tasks that are difficult to complete, finds a new psychology study.

People can handle the truth (more than you think)

September 19, 2018
Most people value the moral principle of honesty. At the same time, they frequently avoid being honest with people in their everyday lives. Who hasn't told a fib or half-truth to get through an awkward social situation or ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.