Can drug cravings be halted through painless, non-invasive brain stimulation?
Joshua Brown is testing this theory as part of his research for IU's Responding to the Addictions Crisis Grand Challenge initiative. Taking advantage of recent breakthroughs in deep-brain stimulation techniques, as well as findings from his innovative brain imaging work at IU, Brown hopes his research leads to the development of an inexpensive headband device that would safely suppress cravings and support individuals in overcoming addiction.
“This technology opens up a whole new set of possibilities for treating addiction,” Brown said. “We envision a lightweight headband that can be worn to generate precise electrical signals that block cravings and help people avoid relapse to drug use.”
Brown is a professor in the College of Arts and Sciences' Department of Psychological and Brain Sciences at IU Bloomington. His background in both mechanical engineering and neuroscience informs his approach to the problem of addiction. The experimental technology works by applying a harmless, high-frequency current of electricity (powered by a 9-volt battery) at four specific points on the scalp.
“This type of therapy is common for stimulating changes to brain activity in outer portions of the brain (near the skull), but until recently it has not been possible to use this method to target deeper portions of the brain (closer to its center),” Brown said. “The problem we are trying to overcome is how to stimulate these interior areas without disrupting brain activity in the outer regions through which the current must pass when it is applied to the skull.”
Brown's project will test a new technique developed by researchers at MIT that uses higher-frequency currents to isolate the deeper brain regions. The technique works by setting the currents at two slightly different frequencies, which produces a new wave pattern when the currents are combined. On its own, either electrical frequency would be too high to affect brain activity, but the combined pattern is at a low enough frequency to produce brain stimulation.
The positioning of the electrodes on the skull will determine the specific area where the electrical fields intersect within the interior of the brain, where the lower-frequency pattern will appear. In this way, deeper regions of the brain can be targeted for non-invasive stimulation without affecting the brain's outer regions.
Based on previous neuroscience research showing the cessation of drug cravings in response to disruptions in specific regions of brain activity, this low-frequency zone of electrical interference could potentially be effective in suppressing cravings and withdrawal.
Brown's prior research at IU helps to indicate which brain regions should be targeted and provides a means to directly observe the effect of the treatment—on both the brain and behavior—in real time. Using a programmable e-cigarette that his team developed for use inside a magnetic resonance imaging facility, Brown pioneered a method for mapping brain activity related to decision-making regarding drug use. His research observed which portions of the brain were active when subjects experienced cravings and when they considered different options for obtaining the drug.
Nicotine-dependent individuals in his study who had abstained from smoking the day of the experiment were given the opportunity to make decisions by choosing either a guaranteed small amount of nicotine or an uncertain chance of receiving a larger amount (or none at all).
This approach enabled Brown to pinpoint parts of the brain that were active both in drug craving and in weighing the risks and benefits of different drug-seeking strategies, adding to a growing body of neuroscience identifying specific sites of brain activity common across all types of drug addiction.
Brown’s Grand Challenges study will use this approach to test whether the new deep-brain stimulation technique alters brain activity in these specific regions and whether this disruption changes subjects’ experience of and response to drug cravings. As with any new potential treatment, the study will first confirm the safety of the method and the absence of unacceptable side effects and will conclude by comparing the effectiveness of the new approach with existing treatments.
“If successful, this type of approach could allow for safe and inexpensive interventions to address a range of disorders associated with the brain’s interior regions, such as chronic pain and schizophrenia,” Brown said.