Can a single dose of ADHD medication reveal how it works in the brain?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion criteria common to all groups: * Subject (male or female) aged 18 to 60 years old * Subject affiliated to a social protection health insurance scheme * Subject capable of understanding the objectives and risks of the research and of providing dated and signed informed consent * Subject having been informed of the results of the prior medical examination * For a woman of childbearing age: negative blood pregnancy test and effective contraception throughout the study (intrauterine device, sterilization, estro-progestogen or progestogen per os, injectable or in the form of an implant or ring) and refusal to perform a pregnancy test before each MRI) Inclusion criteria for Group A: ADHD patients without associated mood disorder (ADHD-P) * Diagnosis of ADHD according to DSM-5 (in particular criterion B: presence of symptoms before the age of 12 years) NB: the diagnosis was not necessarily made at this age. * Subject with or without methylphenidate treatment Inclusion criteria for Group B: Patients with attention deficit disorder due to/accentuated by mood disorders (ADHD-MD) * Association of ADHD symptoms with attentional disorders according to the combination of the following criteria : * Diagnosis of Recurrent Depressive Disorder or Bipolar Disorder according to DSM-5 * Currently euthymic, i.e. a QIDS-16SC depression score \< 6 and a YRMS mania score \< 6, and clinically stabilized for at least 6 weeks prior to inclusion (stable and off-acute treatment). NB: for ISQ item 10 (concentration/decision making, score decision making only) * DSM-5 Adult ADHD Criteria A (at least 5 symptoms of inattention and/or hyperactivity/impulsivity) * Absence of Criterion D during childhood, adolescence and before mood disorders (i.e., no significant impact with reduced quality of social, academic or occupational functioning) * Presence of Criterion D at present (symptoms have a significant impact with a reduction in the quality of social, academic or professional functioning) * Subject with or without approved mood disorder treatment: Mood stabilizers (lithium, valproate, lamotrigine); antidepressants (SSRIs, IRSNa ≤60mg/j of venlafaxine and ≤60mg/j of duloxetine); benzodiazepines in stable doses for more than a month. * Subject with or without methylphenidate treatment Inclusion criteria for Group C: healthy subjects control \- Subject with no psychiatric or neurological history Exclusion criteria common to all groups * Subjects with contraindication to methylphenidate : * hypersensitivity to the active substance, * glaucoma, * pheochromocytoma, * treatment with other indirect sympathomimetics or alpha sympathomimetics (oral and/or nasal routes), irreversible MAOIs * Hyperthyroidism or thyrotoxicosis, * Pre-existing cardiovascular disorders including severe hypertension, heart failure, occlusive arterial disease, angina pectoris, congenital heart disease with hemodynamic impact, cardiomyopathy, myocardial infarction, arrhythmias and potentially life-threatening ductopathies (disorders caused by ion channel dysfunction), * Pre-existing cerebrovascular disorders, brain aneurysms, vascular abnormalities including vasculitis or stroke, * wheat allergy (other than celiac disease) * Diagnosis or history of severe depression, anorexia nervosa or anorexic disorder, suicidal tendencies, psychotic symptoms, severe mood disorders, mania, schizophrenia, psychopathic or borderline personality disorder. * Diagnosis or history of episodic and severe (type 1) (and poorly controlled) bipolar (affective) disorder. * Subjectis with contraindication to performing an MRI: presence of non-removable ferromagnetic body, prosthesis, pacemaker, medication delivered by an implanted pump, vascular clip or stent, heart valve or ventricular shunt * History that may affect brain anatomy or be related to an abnormality (neonatal suffering, neurosurgical operation, comitiality, stroke, head injury with unconsciousness of more than 15 minutes and mental retardation) * History that may affect brain function (general anaesthesia or ECT within 3 months prior to inclusion) * Substance Use Disorder as per DSM-5 criteria (except tobacco) * Pregnant women or, in women of childbearing age and ability (non-sterile), lack of effective contraception * Breastfeeding women * Severe or unstable somatic pathology. * Subject deprived of liberty, or in care under restraint * Subject under safeguard of justice * Incompetent subject (subject to a legal protection measure: curatorship, guardianship, future protection mandate, family habilitation) * Impossibility to give informed information about the subject (subject in an emergency situation, difficulties in understanding the subject, ...) * Subject in exclusion period defined by another protocol in progress Exclusion criteria for Group A: ADHD patients without associated mood disorder (ADHD-P) * Current Mood Disorder * History of bipolar disorder in a first-degree relative * Taking unauthorized psychotropic drugs: all antidepressants, antipsychotics, sedative antihistamines, regular hypnotics, benzodiazepines in unstable doses. Exclusion criteria for Group B: Patients with attention deficit disorder due to/accentuated by mood disorders (ADHD-MD) * Acute phase of mood disorder defined by scores a depression score in the QIDS-16SC ≥ 6 and a mania score in the YRMS ≥ 6. NB: for ISQ item 10 (concentration/decision making, score decision making only). * Use of unauthorized psychotropic drugs including antipsychotics, sedative antihistamines, high-dose IRSNa (\>150mg/d venlafaxine and \>60mg/d duloxetine), MAOIs, tricyclic antidepressants, benzodiazepines in unstable doses.