EEG-MRI Imaging of Methylphenidate Effects in Adult ADHD and Attentional Symptoms in Mood Disorders

Attention Deficit Hyperactivity Disorder (ADHD) in adults is a common psychiatric disorder, with important consequences in terms of quality of life, mental health (associated disorders and poorer response to treatment), family life, risk of accidents; with a consequent cost for society.

Adult ADHD is frequently associated with psychiatric co-morbidities, and notably associated with mood disorders (major depressive disorder or bipolar disorder) in about 50% of cases.

The diagnosis of ADHD in adults is made in patients with an attentional complaint (pure ADHD or ADHD-P), but also very often in the management of a comorbid mood disorder (ADHD associated with mood disorder, or ADHD-MD). In this case, the ADHD had no impact during childhood and adolescence.

Medication management is well established for ADHD-P, and medication is based on methylphenidate, which has a rapid and significant effect on attentional symptoms and impulsivity. However, in the case of ADHD-HD, there is little evidence of treatment efficacy and the mechanisms of action of methylphenidate at the brain level are poorly understood.

The aim of the study is to determine the neural mechanisms of the effect of methylphenidate, using functional MRI and EEG, in ADHD-P and ADHD-HD patients, and to compare them to healthy subjects. A single dose allows us to observe effects that are then persistent with repeated doses. The aim is to determine, by means of a biomarker, whether methylphenidate treatment responds to the same mechanisms in the different groups and would be relevant in ADHD-P as in ADHD-HD.

Main objective:

To determine whether methylphenidate impacts differently on brain circuits associated with cognitive functions in the two clinical populations studied (adult ADHD patients and patients with post mood disorder attentional deficit) and in comparison to controls.

Secondary objectives:

1. To determine the effect of methylphenidate on baseline brain flow in the two clinical populations and in controls (healthy subjects). 2. To determine whether methylphenidate has a different impact on cognitive performance in the two clinical populations studied and in comparison to controls (healthy subjects). 3. To confirm the effect of methylphenidate on the maintenance of cortical arousal. 4. To distinguish the brain networks impacted by methylphenidate (maintenance of attention or inhibition) with MRI and EEG.