Stimulation of the addicted brain Magnetic stimulation as add-on treatment for alcohol use disorder

Non-invasive neuromodulation (i.e. transcranial Electric Stimulation and Transcranial Magnetic Stimulation) has become increasingly popular. These techniques are able to manipulate neural activity and thereby potentially affect behavior and executive functioning. It is for this reason that non-invasive neuromodulation, including TMS, is studied as novel add-on treatment for alcohol and substance use disorders, a disorder with frequent diminished executive functioning. In this thesis, Renée Schluter investigated the effect of non-invasive neuromodulation on executive functioning in healthy individuals and patients with a substance use disorder. Furthermore she studied Transcranial Magnetic Stimulation as add-on treatment for alcohol use disorder.
The main findings presented in this thesis can be summarized as follows: first, in healthy individuals non-invasive neuromodulation only affected impulse control, other executive functioning domains (such as working memory and flexibility) were not affected. Furthermore, one single session of TMS changed resting state functional connectivity in the salience network. These results indicate small and specific effects of non-invasive neuromodulation in healthy individuals. Second, the reviewed effects of noninvasive neuromodulation on executive functions in substance use disorder studies were inconclusive. This was caused by variety in stimulation protocols and behavioral task paradigms, which impaired proper comparisons. Third, TMS add-on treatment did not affect executive functions in patients with an alcohol use disorder in treatment. Add-on treatment also did not affect relapse rates and experienced craving six months after treatment. Future preregistered multicenter randomized controlled clinical trials are required in order to substantiate evidence on effects of TMS add-on treatment in substance use disorders.