Repetitive transcranial magnetic stimulation (rTMS) has been shown to reduce craving in cocaine addicts in the short term. However, there are no studies on the long term clinical and cognitive effects of sustained rTMS therapy. Moreover, clinical improvement or decline could be related to long term changes in brain structure and function. The purpose of this study is to investigate the short and long term clinical and cognitive effects of repetitive Transcranial Magnetic Stimulation (rTMS) at 5 Hz and/or 10 Hz frequencies on the left dorsolateral prefrontal cortex in cocaine dependent patients and to examine possible changes in brain structure and functional connectivity associated with this intervention. For this purpose the investigators will recruit cocaine dependent patients and stimulate them using rTMS with a acute intervention (twice a day for 2 weeks) and a maintenance intervention (twice a week for 3 months). The investigators will follow the patients to determine clinical outcome. The investigators will also measure clinical, cognitive and brain structural and functional connectivity to asses changes related to the intervention in the short and long term (measurements at: baseline, 2 weeks and 3 months).~Procedure:~The projects consists of: Screening Visit, Part 1 and Part 2.~First, there will be a screening visit, where a clinical interview will be conducted and tests will be applied to select study participants who meet the inclusion and exclusion criteria.~Baseline clinical, cognitive and neuroimaging data will be acquired. The cognitive and neuroimaging data will be exploratory, to be associated with the outcome measures. Part 1 of the study entails the determination of the rTMS target frequency (5 or 10 Hz) for Part 2 (long term stimulation). In Part 1, all participants will be randomly assigned to one of the four treatment legs with rTMS (10Hz, 10Hz-Sham, 5Hz, 5Hz-Sham). Participants will receive 20 sessions of rTMS (intervention or sham), twice per day for 10 consecutive days. Each session lasts approximately 35 minutes.~At 2 weeks, the investigators will evaluate the short term effect of treatment by measuring clinical, cognitive and neuroimaging changes and select which frequency of stimulation is the most effective in terms of clinical improvement, but also in terms of the rate of secondary effects. Our hypothesis is that 5 Hz is as effective as 10 Hz without the high rate of secondary effects (i.e. seizures).~In Part 2 of the study, the sham groups will end and they will be invited to the treatment condition although they data not will be considered for later phases. Here the maintenance phase starts (long term), where rTMS will be performed twice a week for 12 months using the target frequency (5 or 10 Hz). Clinical, cognitive and neuroimaging data will be acquired at 2 weeks and 3 months.
The purpose of this study is to investigate the short and long term clinical and cognitive effects of repetitive Transcranial Magnetic Stimulation (rTMS) at 5 Hz and/or 10 Hz frequencies on the left dorsolateral prefrontal cortex in cocaine dependent patients and to examine possible changes in brain structure and functional connectivity associated with this intervention.