GPT and alcohol abuse: Primary: - Safety - Changes in self-reported alcohol  consumption 6 months after  implantation compared to baseline,  using the timeline follow-backSecondary: - Alcohol Use Disorder  Identification Test - Obsessive-Compulsive Drinking  Scale - Alcohol Urge Questionnaire - Alcohol Dependency Scale - Hamilton Depression Rating Scale - Beck Anxiety Inventory - Beck Depression Inventory - Liver Function Tests (AST, ALT)