Repetitive transcranial magnetic stimulation (rTMS) has been shown to reduce craving in cocaine addicts. However, the efficacy of rTMS in treating cocaine addiction has not been evaluated in double-blind, sham-controlled studies and also, we lack a full characterization of rTMS effects on other important aspects, including effects on mood, cognition and changes in brain function. The purpose of this study is to investigate the effects of repetitive Transcranial Magnetic Stimulation (rTMS) at 15 Hz frequency on the left dorsolateral prefrontal cortex in cocaine dependent patients and to examine possible changes in mood, cognition, and brain activity and functional connectivity associated with this intervention. For this purpose, the investigators will recruit cocaine dependent patients. After screening and informed consent, participants will undergo active or sham rTMS for two consecutive weeks (twice a day) during the continued treatment phase, and a maintenance intervention (twice a week for 3 months), during the rTMs follow-up phase. Following this phase, participants will be followed for further 3 months, during which no rTMS will be delivered but clinical and imaging data will be collected. The investigators will also measure clinical, cognitive and brain structural and functional connectivity to assess changes related to the intervention in the short and long term (measurements at: baseline, 2 weeks, 3 months, 6 months).

Procedure: The project consists of: Screening Visit (baseline), Part 1 (continued treatment phase), Part 2 (3 months- rTMS follow-up), Part 3 (3 months follow-up without rTMS). First, there will be a screening visit, where a clinical interview will be conducted and questionnaires and tests will be administered to identify study participants who meet the inclusion and exclusion criteria. Baseline clinical, cognitive and neuroimaging data will be acquired. The neuroimaging data will be exploratory, to be associated with the outcome measures. In Part 1, all participants will be randomly assigned to one of the two treatment arms with rTMS (15Hz, 15Hz-Sham). Participants will receive 2 sessions of rTMS (active or sham), twice per day for 10 consecutive days, for a total of 20 rTMS sessions. Following this, the investigators will evaluate the acute effect of treatment on cocaine craving and consumption, mood and cognition. Also, they will collect exploratory neuroimaging data (functional MRI and resting state functional connectivity). In Part 2 of the study, all participants will continue the assigned treatment arm with rTMS (15Hz, 15Hz-Sham) for three months. Participants will receive 2 sessions of rTMS (active or sham) once per week; clinical and cognitive data will be acquired once per month. The investigators will evaluate the effect of treatment on cocaine craving and consumption, mood and cognition. Also, they will collect exploratory neuroimaging data (functional MRI and resting state functional connectivity). In Part 3 of the study, participants will not receive any rTMS session. Clinical and cognitive data will be acquired once per month for three months. The investigators will evaluate the long-term effect of treatment on cocaine craving and consumption, mood and cognition.