Neuroscience: Brain network linked to disrupting substance addiction identified

Brain lesions that lead to spontaneous remission of tobacco addiction in humans affect part of a common brain network, according to a study published in Nature Medicine. Further evidence for commonality of this network across different substance addictions suggests a potential new target for neuromodulation therapies.

Substance addiction is a public health crisis and a leading cause of death, particularly among young people. Neuromodulation treatments — such as neurosurgical lesioning and brain stimulation — are promising treatment options; however, the absence of a clear therapeutic target has limited their efficacy. Brain lesions caused by injury, such as a stroke, can lead to addiction remission in rare circumstances. Therefore, lesions that result in a therapeutic benefit could potentially help to identify effective targets to treat addiction.

Juho Joutsa, Michael Fox and colleagues analyzed brain scans from 129 patients (60% male; average age of 56 years) addicted to smoking at the time they experienced localized brain damage, of whom 34 subsequently experienced spontaneous addiction remission (defined as being able to easily quit smoking immediately after injury, with no evidence of cravings or relapse). The authors reveal that although lesions associated with remission occurred in multiple locations in the brain, they could all be mapped to a specific brain network. This network was reproducible in other substances of abuse in independent groups of people with brain lesions. This included people with a reduced risk of alcohol addiction and case reports of lesions that disrupted addiction to substances other than nicotine.

The authors conclude that these findings suggest a shared brain network for addiction across different substances of abuse and potentially identify new targets for neuromodulation therapies aimed at treating addiction. However, they go on to state that further research — notably into the potential side effects that may be associated with these targets — is needed.