Non-invasive brain stimulation techniques
The NIBS techniques repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) have the ability to non-invasively alter neural activity in the brain. In the US, rTMS is an approved treatment for depression and both rTMS and tDCS are used extensively within research settings in relation to a wide range of neurological and psychiatric disorders. Further information regarding both of these techniques is given below. Our group is currently conducting a variety of research studies investigating the effects and therapeutic potential of NIBS in eating disorders - for further details please see the ‘take part in our research’ section.
Video: brain stimulation may reduce symptoms of anorexia
Repetitive Transcranial Magnetic Stimulation (rTMS)
Transcranial Direct Current Stimulation (tDCS)
Transcranial Magnetic Stimulation (TMS) is a non-invasive method of brain stimulation which works via electromagnetic induction – that is, the production of a magnetic field.
A TMS coil is able to alter electrical activity in a nearby conductor. In this case that is the area of the brain under the TMS coil. The magnetic field can safely penetrate the head without pain.
When the magnetic pulses generated by a TMS coil are administered in rapid succession, it is referred to as “repetitive TMS “ or “rTMS”, which can produce longer lasting changes in brain activity.
rTMS has been shown to be a safe and well-tolerated procedure. An approved treatment for depression and used widely within other research and clinical settings.
Transcranial direct current stimulation (tDCS) is a non-invasive, painless brain stimulation treatment that uses a weak electrical current to stimulate specific parts of the brain.
A constant, low intensity current is passed through two electrodes placed over the dorsolateral prefrontal cortex (DLPFC) in order to modulate neuronal activity.
There are two types of stimulation with tDCS electrodes: anodal and cathodal stimulation.
Anodal stimulation acts to excite neuronal activity while cathodal stimulation inhibits or reduces neuronal activity and the weak current runs between these two electrodes.
Several studies suggest it may be a valuable tool for the treatment of neuropsychiatric conditions such as depression, anxiety, Parkinson’s disease, and chronic pain.
Currently, tDCS is not an approved treatment for depression, however the technique is being increasingly researched for its therapeutic potential in a wide variety of conditions, including those involving food cravings and addiction.