Can MRI or other brain imaging diagnose ADHD?

Magnetic Resonance Imaging (MRI) is an important research area, and it’s also a “hot topic” with periodic excited claims in the media. I discuss this in the context of various new treatment claims for ADHD and try to separate the wheat from the chaff in my book,  Getting Ahead of ADHD. So far, the bottom line is that brain imaging can’t diagnose ADHD or its subtypes, despite frequent claims that it can (based on single, small studies).

My research team and others are now undertaking a new generation of studies using advanced nonlinear equations (called machine learning) to improve prediction. These are powerful methods and there is reason to be hopeful. However, results from existing studies do not yet offer clinical value. One limitation is that sample sizes tend to be extremely small (often less than 100 children)—such samples are prone to chance findings that will not generalize, not matter how clever the analysis is. Scientists attempt to overcome this with re-sampling methods within their study (one common method is called “k-folds” cross validation). That is of some help, however, the acid test is whether the prediction holds up in a completely new, independent sample of children. Typically, that check is not even done. When it has been done, results are generally disappointing. This generalizability problem is challenging and it will be some time before it is solved. However, many research groups, our own included, are trying hard to do this. I have high hopes that we will eventually succeed. So stay tuned, but for now, remain skeptical of claims for breakthrough brain imaging diagnostics for ADHD. I do not advise you to seek brain imaging for a clinical case of ADHD in the absence of other medical indication and nothing has changed with recent publications or press reports. Check back here or sign up for e-mail updates. We will be tracking this literature and I will share significant findings with you.

As always, let’s keep our eye on the science for reliable answers.

Are Computerized Attention Games Helpful for ADHD?

Are We There Yet?

The effectiveness of computerized attention games is a “hot topic” area and potentially exciting–but emphasis on “potentially.” The Science Says: It’s not there yet.

Researchers have been trying for decades to use computerized training programs to help people with cognitive skills, like reading, memory (particularly in older adults), as well as attention. I discuss new and developing treatment ideas, and sort fact from fiction, in Getting Ahead of ADHD (I discuss brain training at some length in Chapter 5 ).

What The Science Says

Computer training programs for some academic skills, like reading and math, are potentially helpful, and there is some promise in improving children’s academic skills and learning with attention training. But when it comes to ADHD itself, the data are underwhelming.

In “open label” tests (with no control group, and no “blinding” or disguising of the fact they are trying a special intervention), children’s attention (or other skill) improves somewhat. But those designs are only a first, minimal test—they do not rule out placebo or expectancy effects. Sometimes, even on well-controlled experiments a computer program can improve children’s scores on attention and other tests of cognitive skills. However, so far, the best summaries of controlled trials, using raters who are blind to the treatment condition (placebo or active), fail to see improvement in ADHD symptoms from computerized cognitive or attention training.

The Effectiveness Of Computerized Attention Games Is Still Under Study

Now, as computer games get more emotionally engaging and realistic, “next generation” training programs deserve to be studied—they may one day get there. If they do, then it will be important to discover whether the money and time spent on the computer training did more good for the ADHD (or learning, or other target problem) than an equal effort on physical exercise, counseling, skill based learning, or other intervention. It may be that in the future certain aspects of ADHD are helped, at least for some children, and that ultimately this can be identified and verified.  In the meantime, parents can expect to see periodic, excited press releases as first tests come out on new computerized programs. Remember, these are likely to be preliminary results. For now, be somewhat skeptical. Computerized training is not ready for prime time as an ADHD treatment quite yet.

Does ADHD treatment suppress growth? Recent findings

One of the oldest controversies about ADHD medication treatments is their effect on physical growth.

In fact, this still remains controversial, as I explain in a special science pull ADHD growthout in chapter 8 of Getting Ahead of ADHD. Stimulant medicines suppress appetite, and this is why kids may fall behind on growth. The most recent study, published just a few months ago in June of this year, followed a large group of boys from age 7-10 up to age 25. They were grouped as medication treatment having been: (a) negligible, (b) inconsistent, or (c) consistent.Ongoing treatment with stimulant medication yielded about a 2.4-centimeter (about 1-inch) reduction in final adult height. Other prospective studies using other methods do not see this effect. While some controversy remains, it seems likely that ongoing use of stimulant medication can suppress adult height by 2-3 centimeters, at least in boys. However, this and other findings could also be interpreted as suggesting important variation in how children respond—some may see a large height reduction, some may see no height reduction. The take home message is that your prescribing physician should carefully track your child’s growth trajectory and if the child is falling off the growth curve, discuss with you the options for a reduction, pause, or changing in the treatment.  

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Always Look For The Science

You can find it in Getting Ahead of ADHD and with every Dr. Nigg blog post:

Young adult outcomes in the follow-up of the multimodal treatment study of attention-deficit/hyperactivity disorder: symptom persistence, source discrepancy, and height suppression.Swanson JM, Arnold LE, Molina BSG, Sibley MH, Hechtman LT, Hinshaw SP, Abikoff HB, Stehli A, Owens EB, Mitchell JT, Nichols Q, Howard A, Greenhill LL, Hoza B, Newcorn JH, Jensen PS, Vitiello B, Wigal T, Epstein JN, Tamm L, Lakes KD, Waxmonsky J, Lerner M, Etcovitch J, Murray DW, Muenke M, Acosta MT, Arcos-Burgos M, Pelham WE, Kraemer HC; MTA Cooperative Group. J Child Psychol Psychiatry. 2017 Jun;58(6):663-678. doi: 10.1111/jcpp.12684. Epub 2017 Mar 10.

ADHD is Related to Social Disadvantage

What does it mean?

A new article from my team was released this week, showing that ADHD is related to social disadvantage. That means that if a family is in poverty or low income, or is experiencing what social scientists call “low social status” due to lack of parental education or low paying job, that the chances of a child having ADHD are higher. We showed clearly that the effect is not explainable by the fact that social disadvantage and ADHD also both overlap with children’s general behavior problems, and also not explained by the fact that adults with ADHD (who also have kids with ADHD) tend to obtain less education and less well paying jobs. There seems to be an actual effect of social disadvantage on ADHD itself.

Why would this be?

My hunch is that these socio-economic challenges are associated with chronic stress for parents and for kids. Less resources, more stress. If you are in this situation, you already knew this! Chronic stress builds up physical inflammation and other cell damage in the body of the individual. This physical wear and tear has a fancy scientific term: allostatic load. Scientists are learning how to measure it in the body. It fits with an emerging idea that inflammation contributes to the development of ADHD. What should you do? Recognize that chronic stress can add to ADHD risk, and do what you can do build up your social supports and physical health (for you and your children) and also give permission to yourself to engage in your own self-care. Recognize that as you manage stress levels in your own life, you are also helping your child.

Read more here!

Cortical Thickness in ADHD

Cortical thickness- It’s not just when but where

MRI brain imaging has opened up new vistas for understanding child development including how cortical thickness is involved with ADHD. One discovery is that to understand the brain in ADHD we have to think in four dimensions–it’s not just the ​location, or ​volume or activity of brain regions, but when in development the brain develops.
For example, one large study found that by adulthood, the cortical thickness pattern was t​he same in individuals with high and low IQ. However, that pattern was achieved at a different age by those with higher IQ. A related study found that by young adulthood, the cortical thickness pattern is the same for ADHD and non-ADHD children–but again, the pattern was reached at different points in development. The trajectory was different.
It is not just how the brain looks but how it got there that matters – for ADHD and other conditions. We​ and other research groups are now studying which ​aspects of brain development are associated with improvement in ADHD. Read more in my book, Getting Ahead of ADHD.

Cause and Effect in ADHD- Sorting Out the Difference

Cause and Effect – Obesity

Comprehensive studies, including one published by our group, now show that ADHD is correlated with being overweight/obese. In our review, we noted that this effect is more pronounced in adults than in teens or children. In fact, for pre-pubertal chidlren with ADHD, the very few data available do not suggest they tend to be overweight. This developmental pattern implies that ADHD may be a risk factor for obesity. it is easy to speculate that ADHD might lead to more impulsive or undisciplined eating, for example. But there may be biological linkages too. One possible linkage is dopamine functioning in the brain. When dopamine levels are not optimal, motivation and attention falter, and craving can set in for sugary foods (as well as for drugs, in some individuals). However, another possible linkage is inflammation in early development–some research suggests both genetic and environmental triggers in early life that could drive both ADHD and obesity as outcomes sharing a similar outside cause. Overall, the correlation of ADHD and obesity provides a possible further clue to the biology of both conditions, as well as a flag for clinicians to monitor individuals with ADHD for health outcomes.
Cause and Effect – Consult the Science
One of the mysteries of ADHD, like many mental, emotional, and behavioral health conditions, is that it is difficult to establish cause and effect. For example, many children with ADHD have problems on psychological tests of cognitive abilities like executive functioning. Is this cognitive weakness part of the cause of ADHD, or more like another symptom of the condition? It is very difficult to tell. This is why in Getting Ahead of ADHD we place so much emphasis on prospective studies (to see what comes first–consistent with cause but does not prove it), on randomized experiments (which prove causality but are difficult to do in humans), and on other clever designs that provide some evidence about causality, like genomic stratification designs (highly suggestive but not as definitive as randomized experiments). From those studies we now know that several environmental inputs do in fact have a causal influence. For example, we know that omega 3 (“good fat”) levels in the body both improve the development of attention in babies and influence ADHD symptoms in children. We know that exposure to lead has a causal influence on ADHD symptoms. These are not merely correlations. But we know the effects are not total–these are not sole causes. We also know the effects vary–some kids are more susceptible than others. Therefore, these findings lead to more scientific questions, that we are now studying, like: How big are those effects? And what is the individual variation–who is most affected? Stay tuned as we try to learn more.