NICAP

NICAP - Neuroimaging of the Children’s Attention Project - Ireland

This is a collaborative study with the ‘Neuroimaging of the Children’s Attention Project’ (NICAP), https://bmcpsychiatry.biomedcentral.com/articles/10.1186/s12888-016-0770-4,  a large and comprehensive Australian longitudinal multimodal neuroimaging study led by Prof Tim Silk in Melbourne.

In Trinity College Dublin, the project is led by principal investigator Prof. Jane McGrath (Principal Investigator, Associate Professor of Child and Adolescent Psychiatry and Consultant Child and Adolescent Psychiatrist) and Prof. Rob Whelan (co-Principle Investigator, Associate Professor, School of Psychology). Michael Connaughton (PhD candidate) is currently analysing neuroimaging data collected on 150 children and adolescents with ADHD across three time-points.

The study aims to determine how brain structure and function change with age in ADHD, and whether different trajectories of brain development are associated with variations in outcomes including diagnostic persistence, and academic, cognitive, social and mental health outcomes. This project involves multimodal functional and structural neuroimaging analysis in children and adolescents with ADHD.

During the first phase of this project, a systematic review of research investigating microstructural organisation of white matter amongst children and adolescents with ADHD was carried out. The main findings were that there is atypical white matter microstructure in many neural networks in children with ADHD, and that interestingly, this atypical white matter appears to predominantly occur in brain regions that are associated with key neuropsychological functions that are atypical in ADHD. Full text of this paper is available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8842077/

Data analysis of the NICAP longitudinal ADHD dataset is ongoing

Understanding the mechanism of action of methylphenidate in ADHD: A computational psychiatry approach

Approximately 1-in-20 children worldwide have ADHD, a condition associated with disabling inattention, hyperactivity and impulsivity. These problems can manifest as poor inhibitory control (e.g., difficulty holding back impulsive actions) and atypical reward processing (e.g., failing to learn from adverse outcomes). Poorly treated ADHD is associated with negative academic and socioeconomic consequences.

This project aims to ultimately improve clinical management of children with ADHD. Methylphenidate, a stimulant medication, is used as the first-option pharmacological treatment for ADHD, is very commonly prescribed and often successfully reduces problem behaviour. Although Methylphenidate can be extremely effective, it does not work for every child. There is currently no ‘objective’ way (e.g., blood test or brain scan) to measure how      a child is responding to Methylphenidate. Instead, clinicians must rely on reports from parents and teachers, an approach that is problematic and that often leads to delays in optimising ADHD treatment. The absence of a biological test to quantify Methylphenidate response is primarily because we do not understand exactly how Methylphenidate changes behaviours to produce the known beneficial effects.

This project will investigate the specific brain processes that are affected by Methylphenidate by recording brain activity and behaviour in children with ADHD (who have already been prescribed Methylphenidate as part of their clinical care) when they are on and off this medication. Brain activity will be recorded using two separate approaches, which are both non-invasive and routinely used in Trinity College Institute of Neuroscience: electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). Brain activity data will be collected while children with ADHD are performing two computer-game like tasks. One task measures the child’s ability to hold back impulsive actions (inhibition) and the other assesses how they learn from positive and negative outcomes (reward processing). The data from the two tasks, the EEG recording, and the fMRI scan will be analysed using advanced computer-modelling approaches to determine exactly how Methylphenidate changes behaviour.

This project is important because if we can understand the brain mechanisms affected by Methylphenidate, we may ultimately be able to develop a computerised measure that will allow clinicians to predict whether a child is going to respond to this treatment or not. Such a measure would allow clinicians to treat ADHD more effectively and would result in children with ADHD experiencing faster relief from symptoms.