Professor Jim Swanson
The course and outcome of childhood ADHD: what have we learnt from the MTA study?
The first presentation of the EUNETHYDIS International Conference on ADHD 2018 was a keynote talk by Professor Jim Swanson (Child Development Center, University of California, Irvine, CA, USA), who focused on the long-term outcomes of childhood ADHD as seen in the 2-decade-long Multimodal Treatment of ADHD (MTA) study.
Professor Swanson began his presentation with an overview of the MTA study, which was initiated as a 14-month randomised clinical trial in children aged ~7–10 years (N=579), and continued as a 16-year, long-term observational follow-up study (515 patients agreed to continue and 289 classmates [258 without ADHD] were added as a local normative comparison group), with patients in their early-to-mid 20s.1
Following the study overview, Professor Swanson looked at some of the key differences between adult persisters and remitters in the MTA study, before focusing on specific factors.2 He noted that although symptom severity may decrease over time in those with ADHD, functional impairment may increase.3 Substance use among those with ADHD was compared with those without ADHD, and the impact of early initiation of substance use was also analysed.4,5 Finally, the association of ADHD medication use with alteration of growth and tempo of growth in children diagnosed with ADHD was discussed.1
Professor Swanson concluded by noting that various investigations of the MTA study data are still ongoing and that further publications are anticipated.
Professor Swanson: “The MTA study is one of the best randomised clinical trials in child psychopathology.”
Professor David Coghill
Is ADHD in adults a disorder of executive failure? What have we learnt from the investigation of persisters and remitters in young adulthood?
Neurocognitive investigation of persisters versus remitters
In this symposium chaired by Professor Philip Asherson (King’s College London and Maudsley Hospital, London, UK), the opening presentation by Professor David Coghill (Department of Paediatrics and Psychiatry, University of Melbourne, Melbourne, Australia) discussed the link between improvements in cognition and improvements in symptom measures. He raised the idea that the pathway that is widely considered as a given (that improved cognition is then associated with improvements in symptoms) may not be that simple. Professor Coghill proposed that although treatment may improve symptoms and improve cognition, improvements in these two categories are not necessarily correlated, and suggested that we could potentially consider these two factors in a parallel fashion instead of assuming that one directly influences the other.6
Professor Coghill noted that this line of thought may explain why cognitive training approaches (e.g. working memory training) may not impact on symptoms but may still improve function in patients with ADHD, and why functional impairments may remain even if symptoms are optimally treated. This suggests that it may be important to measure both symptom and cognitive outcomes.
Cognitive-EEG investigation of persisters versus remitters
The symposium then moved on to look at cognitive-electroencephalogram (EEG) research in ADHD persisters and remitters, and Professor Jonna Kuntsi (Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK) discussed the Sibling EEG Follow-Up Study (SEFOS). She described markers of remission (preparation-vigilance and error detects), processes not associated with outcome (executive control and potential peripheral hypoarousal) and potential moderators of outcome (IQ, ADHD severity and socioeconomic status).7-11
Professor Kuntsi concluded that if we are able to find predictors of ADHD persistence, we may be able to identify those at greatest risk. This highlights the importance of obtaining information on every patient from multiple sources, to ensure all relevant information is known. Professor Kuntsi noted that, in her opinion, results from ongoing studies may help show that executive control impairments are not strong candidates for treatment targets for those already diagnosed with ADHD.
Resting-state fMRI investigation of remitters versus persisters
The final presentation of the symposium focused on functional magnetic resonance imaging (fMRI) correlates between ADHD persisters and remitters. Professor Katya Rubia (Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK) introduced the discussion with an overview of the current understanding of brain-function alterations in people with ADHD, highlighting the current knowledge of functional abnormalities in these patients. She then raised the question of whether these abnormalities were still present in adult ADHD persisters, but not remitters.
The remainder of the presentation discussed three potential models of remission: normalisation, compensation, and those with no evidence of change. Professor Rubia highlighted published evidence showing that although there are some cases in which no change is observed, normalisation is reported in remitting patients, compared with persisters, the majority of the time, with compensation being reported in some instances.12-16
Professor Rubia concluded that the current evidence is limited and that larger follow-up fMRI studies are needed to more completely understand the neurobiology and predictors of remission to inform treatment and support recovery.
Professor Coghill: “Executive function is a term that is thrown around quite carelessly. Sometimes we need to look at it as a whole, while other times we need to look at the elements individually.”
Disclaimer: The views expressed here are the views of the presenting physician and not those of Takeda
- Swanson JM, Arnold LE, Molina BSG, et al. Young adult outcomes in the follow-up of the multimodal treatment study of attention-deficit/hyperactivity disorder: symptom persistence, source discrepancy, and height suppression. J Child Psychol Psychiatry 2017; 58: 663-678.
- Hechtman L, Swanson JM, Sibley MH, et al. Functional adult outcomes 16 years after childhood diagnosis of attention-deficit/hyperactivity disorder: MTA results. J Am Acad Child Adolesc Psychiatry 2016; 55: 945-952.
- Howard AL, Strickland NJ, Murray DW, et al. Progression of impairment in adolescents with attention-deficit/hyperactivity disorder through the transition out of high school: contributions of parent involvement and college attendance. J Abnorm Psychol 2016; 125: 233-247.
- Swanson JM, Wigal T, Jensen PS, et al. The qualitative interview study of persistent and nonpersistent substance use in the MTA: sample characteristics, frequent use, and reasons for use. J Atten Disord 2018; 22: 21S-37S.
- Molina BSG, Howard AL, Swanson JM, et al. Substance use through adolescence into early adulthood after childhood‐diagnosed ADHD: findings from the MTA longitudinal study. J Child Psychol Psychiatry 2018; 59: 692-702.
- Coghill DR, Hayward D, Rhodes SM, et al. A longitudinal examination of neuropsychological and clinical functioning in boys with attention deficit hyperactivity disorder (ADHD): improvements in executive functioning do not explain clinical improvement. Psychol Med 2014; 44: 1087-1099.
- Cheung CH, Rijdijk F, McLoughlin G, et al. Childhood predictors of adolescent and young adult outcome in ADHD. J Psychiatr Res 2015; 62: 92-100.
- Cheung CH, Rijsdijk F, McLoughlin G, et al. Cognitive and neurophysiological markers of ADHD persistence and remission. Br J Psychiatry 2016; 208: 548-555.
- Michelini G, Kitsune GL, Cheung CH, et al. Attention-deficit/hyperactivity disorder remission is linked to better neurophysiological error detection and attention-vigilance processes. Biol Psychiatry 2016; 80: 923-932.
- Du Rietz E, Cheung CH, McLoughlin G, et al. Self-report of ADHD shows limited agreement with objective markers of persistence and remittance. J Psychiatr Res 2016; 82: 91-99.
- James SN, Cheung CH, Rommel AS, et al. Peripheral hypoarousal but not preparation-vigilance impairment endures in ADHD remission. J Atten Disord 2017; 1: 1087054717698813.
- Sudre G, Szekely E, Sharp W, et al. Multimodal mapping of the brain’s functional connectivity and the adult outcome of attention deficit hyperactivity disorder. Proc Natl Acad Sci U S A 2017; 114: 11787-11792.
- Szekely E, Sudre GP, Sharp W, et al. Defining the neural substrate of the adult outcome of childhood ADHD: a multimodal neuroimaging study of response inhibition. Am J Psychiatry 2017; 174: 867-876.
- Wetterling F, McCarthy H, Tozzi L, et al. Impaired reward processing in the human prefrontal cortex distinguishes between persistent and remittent attention deficit hyperactivity disorder. Hum Brain Mapp 2015; 36: 4648-4663.
- Francx W, Oldehinkel M, Oosterlaan J, et al. The executive control network and symptomatic improvement in attention-deficit/hyperactivity disorder. Cortex 2015; 73: 62-72.
- Clerkin SM, Schulz KP, Berwid OG, et al. Thalamo-cortical activation and connectivity during response preparation in adults with persistent and remitted ADHD. Am J Psychiatry 2013; 170: 1011-1019.