Neuroimaging of attention-deficit/hyperactivity disorder: current neuroscience-informed perspectives for clinicians

Abstract

The neuroimaging literature on attention-deficit/hyperactivity disorder (ADHD) is growing rapidly. Here, we provide a critical overview of neuroimaging studies published recently, highlighting perspectives that may be of relevance for clinicians. After a comprehensive search of PubMed, Ovid, Web of Science, and EMBASE, we located 41 pertinent papers published between January 2011 and April 2012, comprising both structural and functional neuroimaging studies. This literature is increasingly contributing to the notion that the pathophysiology of ADHD reflects abnormal interplay among large-scale brain circuits. Moreover, recent studies have begun to reveal the mechanisms of action of pharmacological treatment. Finally, imaging studies with a developmental perspective are revealing the brain correlates of ADHD over the lifespan, complementing clinical observations on the phenotypic continuity and discontinuity of the disorder. However, despite the increasing potential to eventually inform clinical practice, current imaging studies do not have validated applications in day-to-day clinical practice. Although novel analytical techniques are likely to accelerate the pace of translational applications, at the present we advise caution regarding inappropriate commercial misuse of imaging techniques in ADHD.

Figure 1

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart of retained studies. * Nineteen studies [1-19] studies were excluded because of sample size <15 (in at least one study subgroup). One study [20] was discarded since results were based on analyses uncorrected for multiple comparisons. Two studies [21;22] assessed individuals with self-reported ADHD symptoms, without a formal interview, and were therefore excluded. One was not an original empirical study [23]. Finally, we did not include two studies that examined, respectively, individuals with ADHD plus Bipolar Disorder [24] and ADHD plus developmental coordination disorder [25]. References of excluded studies are reported in the Supplemental Material (SM 2).