Some head injuries also have something good: in certain cases, a lesion in the brain leads to the fact that people can suddenly stop smoking without any problems. A team led by Juho Joutsa from the University of Turku in Finland has taken a closer look at such spontaneous remissions and identified a brain network that may play a central role in the fight against addiction. This "addiction-remission network" was described by Joutsa and colleagues in the journal "Nature Medicine".
The neuroscientists analyzed brain scans from 129 patients who suffered a brain injury and were nicotine -dependent at the time. Almost every third was no longer cigarette after the accident. However, their damage to different places in the brain were. By analyzing how these regions communicated with each other, they were able to identify a related network. This "addiction remission network" consists of the island bark and parts of the zingular and prefrontal cortex. Experts had previously associated the regions with addictive behavior. What is new, however, is that they work together and make changes in this circuit easier to give up smoking.
The results are particularly robust because Joutsa and his team not only looked at functional connectivity – i.e. how the regions interact with each other – but also found anatomical indications of the network: some patients had injuries in the white matter that connects the corresponding areas to each other.
In a further step, the group was able to demonstrate that damage in the newly discovered circuit was associated with a lower risk of alcoholism in another 186 test subjects. So it seems that the neuronal control loop also plays a role in other substance dependencies. According to Juho Joutsa, the discovery could help to treat dependencies more successfully with brain stimulation techniques in the future, for example by addressing several regions at the same time. In the United States, doctors are already using such procedures to help smoke cessation. So far, however, it was unclear which regions the treatment should best target.
