feasibility reasons.

This phase II pilot study aims at evaluating the benefits and the risks of methylphenidate (Concerta®) for the treatment of cocaine/crack dependence in terms of cocaine/crack use reduction and adverse events.

Patients will receive pharmacotherapy based on methylphenidate (18 mg per tablet) with a 3-week titration phase to a maximum dose of 108 mg per day, with a weekly follow-up during 3 months. Socio-demographic and behavioral data will be collected through phone interviews every month. During medical visits, self-administered and clinical questionnaires will collect clinical and behavioral data. Urine drug toxicologies and blood sampling will be performed to gather biological, pharmacokinetic and pharmacodynamic data.

This study should identify an effective response-dose of methylphenidate for people with a cocaine use disorder. The methylphenidate should be effective to reduce cocaine use in cocaine-dependent individuals with a good tolerability. The results of pharmacokinetic and pharmacodynamic analyses will give us the effective dose of methylphenidate and some information on toxicity to adapt the surveillance in a future clinical trial.

Inclusion Criteria:

• Diagnosed with cocaine/crack/amphetamine derivate dependence using Diagnostic and Statistical Manual of Mental Disorders (DSM V) (and International Classification of Diseases (ICD 10)) and willing to be abstinent.
• Having a cocaine/crack positive urinary test.
• Effective contraception for women of childbearing age.
• Willing to participate.
• Registered at social insurance/security.
• Being able to give consent.
• Reachable by telephone.

Exclusion Criteria:

• Dependence on alcohol and/or other substances.
• Hypersensitivity to the active compound methylphenidate or to filler.
• Glaucoma.
• Phaeochromocytoma
• Family history or diagnosis of Gilles de la Tourette syndrome.
• During treatment with non-selective, irreversible monoamine oxidase (MAO) inhibitors.
• History of hyperthyroidism or of thyrotoxicosis.
• Preexisting cardiovascular problems including severe hypertension, heart failure, arterial occlusive disease, angina, haemodynamically significant congenital heart disease, cardiomyopathies, myocardial infarction, potentially life-threatening arrythmias and channelopathies, (disorders caused by the dysfunction of ionic channels).
• Preexisting cerebrovascular disorders, cerebral aneurism, vascular abnormalities including vasculitis or stroke.
• Diagnosis or history of severe depression, anorexia nervosa/anorexic disorders, suicidal tendencies, psychotic symptoms, severe mood disorders, mania, schizophrenia, psychopathic/borderline personality disorder
• Diagnosis or history of severe and episodic (Type I) Bipolar (affective) Disorder (that is not well-controlled)
• Suicidal tendencies or characterized suicidal syndrome.
• Pregnancy, breast-feeding or absence of any contraception for female participants.
• Unstabilized psychiatric comorbidity likely to compromise adherence to treatment.
• Comorbidity or handicap likely to corrupt evaluation.
• Organic pathology severe enough according to the investigator, likely to comprise adequate surveillance during the trial.
• Patient about to leave the area for a period of time preventing his/her adequate participation in the trial.
• Insufficient motivation.
• Participation in another clinical trial with an on-going exclusion period at the time of the pre-inclusion visit.
• Lack of medical insurance.
• Unreachable by phone.
• Patient on mandatory treatment.
• Patient with legal incapacity (under guardianship or curatorship)