There are few things that can have as wide-ranging and dramatic effects on everyday function as brain damage. The brain packs many functions into a super-dense structure, meaning that, whether from stroke or head injury, loss of neurons can instantly rob a patient of speech or movement. Now, a surprising new study suggests that rare instances of neuronal loss to certain areas of the brain may also hold the key to overcoming addiction.
American and Finnish researchers collaborated on the new publication in Nature Medicine, which concerned a group of patients who were addicted to smoking when they experienced brain damage. Of this cohort (n=129), 34 found they were able to quit immediately after the damage, did not relapse and reported no cravings.
Examining the patients’ brain scans, the group identified that although the patients that easily beat smoking had damage to different areas of their brain, the affected regions represented parts of a common brain network. Further evidence for commonality of this network across different substance addictions suggests a potential new target for addiction therapies that aim to change brain function.
Brain stimulation for addiction
Previous studies have aimed to alter brain function with the aim of beating addiction. While many used brain stimulation-based approaches, others controversially used surgery that targeted brain areas thought to be involved in addiction. However, the lack of a clear target puts such approaches at risk of causing side effects.
The authors noted in their paper that the damage that disrupted smoking was defined by a pattern of “positive connectivity to the dorsal cingulate, lateral prefrontal cortex and insula, and negative connectivity to the medial prefrontal and temporal cortex.”
The authors showed that the 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.
This article is a rework of a press release issued by Springer Nature. Material has been edited for length and content.
Reference: Joutsa J, Moussawi K, Siddiqi SH, et al. Brain lesions disrupting addiction map to a common human brain circuit. Nat. Med. 2022. doi: 10.1038/s41591-022-01834-y