Neuroimaging in ADHD: From Biomarker Search to Neurotherapy

I will present our latest meta-analytic findings of structural and functional deficits in ADHD, their disorder-specificity relative to other childhood disorders, and discuss recent translational neuroimaging approaches such as imaging-based diagnostic classification and neurotherapies using fMRI-neurofeedback and brain stimulation.

Our most recent structural and functional meta-analyses show that ADHD patients suffer from reduced structure and function in several frontal, striato-limbic and parieto-temporal regions. In fMRI, they also show reduced deactivation of the default mode network, presumably reflecting increased mind-wandering. Our comparative neuroimaging meta-analyses show that the structural deficits in basal ganglia and insula and the functional deficits in inferior frontal cortex are disorder-specific compared to OCD and autism, who share dorsomedial prefrontal deficits.

Translational neuroimaging is still in its childhood. Using imaging data for diagnostic classification has shown limited success in ADHD likely due to its phenotypical and aetiological heterogeneity. Best results have been achieved for homogenous subgroups likely to have similar biotypes, but replications are still outstanding. Neurotherapeutics is an exciting new avenue to target dysfunctional brain regions in ADHD. Their attraction lies in their safety and potential longer-term neuroplastic effects, which drugs cannot offer. I will discuss evidence for potential efficacy of fMRI neurofeedback as well as non-invasive brain stimulation in ADHD.

References:

Hart H, Radua J, Mataix D, Rubia K (2013) Meta-analysis of fMRI studies of inhibition and attention in ADHD: exploring task-specific, stimulant medication and age effects. JAMA Psychiatry 70(2):185-98

Norman, L, Carlisi, C, Lukito S, Hart H, Mataix-Cols, Radua J, D, Rubia, K (2016) A comparative meta-analysis of structural and functional brain abnormalities in ADHD and OCD. JAMA Psychiatry,269:97-105.

Lim L, Marquand A, Cubillo AA, Smith AB, Chantiluke K, Simmons A, Mehta M, Rubia K. (2013) Disorder-specific predictive classification of adolescents with attention deficit hyperactivity disorder (ADHD) relative to autism using structural magnetic resonance imaging. PLoS One 8(5):e63660

Alegria AA et al., (2017) Real-time fMRI neurofeedback in adolescents with attention deficit hyperactivity disorder. Human Brain Mapping, 38(6):3190-3209.