By studying long-time smokers who quit smoking suddenly after suffering brain damage, researchers have been able to map a brain network linked to addiction. According to the authors of the study, published Monday in Nature Medicine, these findings could help better target future treatments for addiction to a range of substances.
To determine where addictions are located in the brain, the researchers looked at 129 patients (60% male, median age 56) who smoked daily and had brain damage. While more than half continued smoking normally after the injury, a quarter quit immediately with no problems, even reporting “no cravings,” according to the study.
An “addiction relief network”
The lesions associated with remission were located in multiple areas of the brain, but would all be connected to a specific network, the researchers believe, who mapped them to a series of brain areas dubbed the “addiction-remission network.” They found that a lesion that caused a person to quit an addiction would likely affect parts of the brain such as the dorsal anterior cingulate cortex, lateral prefrontal cortex, and insular cortex, but not the medial prefrontal cortex.
Previous research had shown that lesions affecting the insular cortex reduced addiction but left out other parts of the brain identified in this new study. To confirm their findings, the researchers looked at 186 patients with brain damage who underwent an alcohol risk assessment. They found that damage to the addiction-related brain network they found in smokers also reduced the risk of alcoholism, “suggesting a common addiction network across these substances.”
In the eyes of the study’s author, Juho Joutsa, a neurologist at Finland’s University of Turku, “the identified network provides a testable target for treatment attempts.” “Some of the nodes of the network were in the cortex, which could be targeted even with non-invasive neuromodulation techniques,” he said. Neuromodulation combines all techniques used to modify the activity of the central, peripheral or autonomic nervous system.
One such technique, a transcranial magnetic stimulation coil, was approved by the US Food and Drug Administration (FDA) for OCD in May and is already targeting many of the same areas of the brain as addiction’s remission network. The study author hopes his research will help develop a coil that targets addiction. “However, the best way to modulate this network has yet to be identified, and carefully designed studies to verify the clinical benefits of targeting the network have yet to be identified,” he said.