Brain Activity Associated With Inhibition of Action in Attention-deficit

Assessment of Brain Activity Associated With Inhibition of Action in Attention-deficit Hyperactivity Disorder

Inhibitory control allows individuals to suppress unwanted actions and to resist irrelevant stimuli. It is thought to be a core deficit in Attention-deficit/hyperactivity disorder (ADHD). The present study aims at evaluating this deficit in adults with ADHD. Executive and inhibitory capacities, as well as the neural mechanisms underlying inhibitory control, will be assessed in adults with ADHD and two control groups of participants.

ADHD is a psychiatric disorder characterized by symptoms of inattention, hyperactivity, and impulsivity (DSM-V, 2013). An impairment of inhibitory control has been suggested as the primary deficit in children with ADHD, which is thought to cause secondary impairments in executive functioning. A few studies investigated executive capacities in adults with ADHD. Specifically, an impairment in action inhibition has been reported in ADHD participants. Moreover, inhibition of action is often associated with distinctive electroencephalographic (EEG) correlates. The present study aim at combining both novel inhibitory control measurement techniques and EEG analysis in temporal and frequency domains to assess the sensitivity and the specificity of an inhibitory deficit in adults with ADHD. This is part of an improvement in the procedures for diagnosing ADHD syndrome and its functional evaluation.

The study will analyze the EEG activity associated with two stop-signal tasks requiring inhibitory capacities. A set of other cognitive skills will also be evaluated during a neuropsychological assessment. The results of ADHD patients will be compared with those of a control group (healthy volunteers) to assess the sensitivity of an inhibition deficit to the disorder. These same results will also be compared with those of a second control group (patients with a negative diagnosis of ADHD) to assess the specificity of the inhibitory deficit.

This experimental strategy results in the involvement of three groups of participants (ADHD patients and two control groups) in three visits (neuropsychological assessment and two EEG sessions).

Inclusion Criteria:

• Age between 18 and 50,

  • Visual, auditory (authorized apparatus), motor skills suitable for the proper realization of neuropsychological tests,
  • Being right-handed,
  • Free, informed and written consent signed by the participant and the investigator
  • Person affiliated or beneficiary of a social security scheme.

• For the ADHD group:

  • Diagnosis of ADHD according to DSM-V criteria (APA, 2013),

For the patient control group:

• Patient who consulted for a cognitive complaint and for whom the diagnosis of ADHD was rejected according to the criteria of DSM-V (APA, 2013).

Exclusion Criteria:

• General or progressive neurological disease resulting in cognitive impairment (multiple sclerosis, Parkinson's disease, stroke, etc.),

• Insufficient linguistic level in French to participate in neuropsychological assessment,

• Patient placed under judicial protection or under another protective regime,

• Severe depression according to DSM-V criteria (APA, 2013),

• Autism spectrum disorder, developmental coordination disorder.

  -For the healthy voluntary control group:

• Presence of a cognitive complaint or pathology which may impair his cognitive functions