April 16th, 2022 
The MRI Race: Brain Volume Deficiency in individuals with ADHD
Student Presenter
Department of Biology, East Central University
19 April 2019
Introduction roadmap
Background
What Is ADHD?
The MRI Race and Why We Care
Paper Citations
Papers
Paper #1
Paper #2
Paper #3
What is ADHD?
Single most common mental disorder affecting children1
5% of all children
2.5% of all adults
Characterized by: Inattention, hyperactivity, and impulsivity
(1) American Psychiatric Association
Stanford Medicine 2015 (image)
ADHD is caused by a wide variety of things. These include problems during pregnancy, premature birth, genetics, and some other things that scientists are still trying to figure out. ADHD is the single most common mental disorder affecting children, affecting 5% of all children and 2.5 percent of adults. ADHD is characterized by inattention, hyperactivity, and impulsivity.
I originally studied ADHD in my honors thesis. As a future developmental pediatrician I will diagnose and treat ADHD more than any other disorder. I have always been interested in the neurobiology behind ADHD, but using MRI to learn more about the specific structures and areas affected will benefit the future patients I look forward to serving.
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The MRI race and why we care
Using MRI to visualize brain volumes:
Unique insight into ADHD brain volume deficiencies
National Institute of Mental Health 2007 (image)
Now we need to talk about the neurobiology of ADHD. Research shows that brains of those with AHD develop at a normal rate but is delayed by an average of three years in certain brain regions. If you look at this picture you can see that certain brain structures are delayed between the important ages of 7 and 13. For example the frontal cortex is delayed. The frontal cortex controls thinking, planning, and attention. All behaviors that are associated with ADHD.
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Paper citations
Paper #1:
Hoogman M, Bralten J, Hibar DP, Mennes M, Zwiers MP, Schweren L, van Hulzen KJE, Medland SE, Shumskaya E, Jahanshad N, et al. Subcortical brain volume differences of participants with ADHD across the lifespan: an ENIGMA collaboration. The Lancet Psychiatry. 2017 Feb 16:1–39.
Paper #2:
Castellanos, F. X.; Lee, P. P.; Sharp, W.; Jeffries, N. O.; Greenstein, D. K.; Clasen, L. S. Developmental Trajectories of Brain Volume Abnormalities in Children and Adolescents With Attention-Deficit/Hyperactivity Disorder. Jama 2002, 288, 1740.
Paper #3:
Batty MJ, Liddle EB, Pitiot A, Toro R, Groom MJ, Scerif G, Liotti M, Liddle PF, Paus T, Hollis C. Cortical Gray Matter in Attention-Deficit/Hyperactivity Disorder. Journal of the American Academy of Child & Adolescent Psychiatry. 2010;49(3):229–238.
____ = date of publication
Paper #1: SubCortical Brain Volume Differences of Participants with ADHD Across the Lifespan: an ENIGMA Collaboration
Mega-analysis
1713 cases (ADHD)
1529 controls
Hoogman et al. 2017
Cliff Notes:
Size deficiency in all regions tested except the pallidum and thalamus
Psychostimulant medication & symptom severity: no effect on size
Paper #2: Developmental Trajectories of Brain Volume Abnormalities in Children and Adolescents With Attention-Deficit/Hyperactivity Disorder
Castellanos et al. 2002
152 cases (ADHD)
139 controls
Cliff Notes:
1. Stimulant medication increases volumes of all structures tested, but not at levels similar to controls
Paper #3: Cortical Gray Matter in Attention-Deficit/Hyperactivity Disorder: A Structural Magnetic Resonance Imaging Study
25 cases (ADHD)
24 controls
Cliff Notes:
Statistical deficit of the pars opercularis cortex
Hypothesis supported
Batty et al. 2010
Pars opercularis because of its connection to inhibitory control, a facet of ADHD behavior.
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Analysis roadmap
Introduction
Methods
Results
Discussion
Overview
Introduction
Paper #1
Pros:
Framing the problem and objectives in separate subsections
Paper #2
Pros:
Detailed literature review
Paper #3
Pros:
Good mix of subject and literature review
Cons:
Missing a hypothesis
Cons:
Abstract skimpy in context and methods; heavy in results
Cons:
Title is general
Methods
Paper #1
Pros:
Repeatable description of overall experiment
Paper #2
Pros:
Repeatable patient gathering/ screening
Paper #3
Pros:
Matched every ADHD case with a control with matching demographics
Cons:
Questionable if experiment can be run without error at every lab
Cons:
Unnecessary page-long description of statistics
Cons:
No plan for MRI scans w/ movement; All participants on medication; 1 female
Results
Paper #1
Pros:
Focused on the effects of secondary variables on specific structures
Paper #2
Pros:
Included data linking behavior ratings with brain structures
Paper #3
Pros:
Data presentation answers objectives and hypothesis
Cons:
2 graphs for 4 data tables
Cons:
1 graph for 3 data tables
Cons:
Used color to distinguish data in a graph
discussion
Paper #1
Pros:
Advocates for DSM update to lower stigma
Paper #2
Pros:
Openly discussed limitations of study
Paper #3
Pros:
Proposed future experiments
Cons:
Discussed limitations, but heavily overshadowed by positives
Cons:
Repeats results
Cons:
Discussed only having a medication group but overlooked past research on subject
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Overview
Paper #1
Pros:
Added Research in context section
Paper #2
Pros:
Data tables easy to read and interpret
Paper #3
Pros:
Free space for eyes to rest
Cons:
Graphs at end of paper
Cons:
Results section of abstract absurdly long
Cons:
Smallest number of brain scans
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Conclusion
My favorite: Paper #1; Hoogman et al. 2017
My least favorite: Paper #3; Batty et al. 2010
Each article added to this body of research in their own distinct way
Interesting Note: Papers 1 & 3 referenced paper 2
Any questions?
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