Influence of Stimulant Medication on Brain Processes for Decision Making in Attention Deficit Hyperactivity Disorder
Condition: Attention Deficit-Hyperactivity Disorder
MeSH terms: Hyperkinesis; Attention Deficit Disorder with Hyperactivity
Study type: Interventional
Phase: Phase 4

Summary: 
      The goal of this trial is to investigate the cognitive- and brain-mechanisms underlying
      decision making (DM) and learning in young adults with Attention-Deficit/Hyperactivity
      Disorder (ADHD) as well as the modulation of task-related and task-independent brain
      activation by methylphenidate. The study aims at using a double-blinded, placebo controlled,
      cross-over, withdrawal design to study the effects of ADHD and methylphenidate in both a
      behavioural study investigating cognitive effects on decision making and instrumental
      learning, and a functional MRI (fMRI) study investigating the effects on brain mechanisms
      during decision making alone. A secondary objective of the trial is to measure the effect of
      adult ADHD and methylphenidate on cerebral perfusion. This will be done through applying a
      novel arterial spin labelling MRI-technique on the participants in the fMRI arm of the study.
    

Detailed description: 
      The immediate scientific goal of this trial is to investigate the cognitive- and
      brain-mechanisms underlying Decision Making (DM) and instrumental learning in young adults
      with ADHD as well as the modulation of task-related and task-independent brain activation by
      MPH. In a more applied perspective, the investigators hope this trial will contribute to the
      development of tools for improved diagnosis and treatment monitoring of ADHD. Diagnostic
      tools should be based on the understanding of cognitive and brain mechanisms contributing to
      the symptom manifestation of ADHD. The study aims at using a double-blinded, placebo
      controlled cross-over withdrawal design to study the effects of ADHD and MPH in both a
      behavioural study investigating cognitive effects on DM and instrumental learning, and an
      fMRI study investigating the effects on brain mechanisms during DM alone. The results of the
      behavioural DM task from the fMRI experiment will be pooled with the data from the
      behavioural study to achieve higher statistical power in the analysis of the behavioural
      data.

      A distinctive characteristic of this proposal is to gain insight into differences between
      ADHD-patients and healthy controls and the effects of methylphenidate (MPH) medication with
      an approach termed "computational psychiatry" (Maia and Frank, 2011). In this approach, the
      investigators apply mathematical models of cognition to observed behaviour in order to derive
      latent decision variables characterizing the DM- and instrumental learning processes. When
      combined with neuroimaging methods, computational models allow identification of differences
      in affective and cognitive processes together with the neurobiological processes that
      underlie these differences (Frank et al., 2004). Such insights should be the foundation of
      new tools for diagnosis and therapeutic treatment of ADHD.
    

Intervention name(s): Ritalin; Placebo
Intervention type(s): Drug; Drug
Intervention description(s): On one of the two test-dates the patient participant is administered methylphenidate, in the dose prescribed by the patients doctor.; On one of the test-dates the patient participants are administered a sugar pill, matching their prescribes medical dose.
Other intervention name(s): Methylphenidate; MPH; Sugar pill
Intervention MeSH terms: Methylphenidate
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Basic Science
Keywords: Decision-Making; functional MRI; pharmacological MRI; Reinforcement Learning; Methylphenidate