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Headlines We Love: ADHD is Biological

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newsboyOkay, the headlines this week may not come as news to us. But, following the recent ADHD Hall of Shame entry, science-based reportage comes as welcome relief. The following news sources, among others, report the latest study by NIDA Director Nora Volkow and colleagues showing that, well, ADHD is real. Read all about it.

Here’s a sampling of the breaking headlines, followed by the press release from the researcher:

  • BBC News: ADHD Brain Chemistry Clue Found
    US researchers have pinned down new differences in the brain chemistry of people with attention deficit hyperactivity disorder (ADHD). They found ADHD patients lack key proteins which allow them to experience a sense of reward and motivation.

    The Brookhaven National Laboratory study appears in the Journal of the American Medical Association.

    It is hoped it could help in the design of new ways to combat the condition.

    For far too long there has been an assumption that children with ADHD are deliberately wilful
    Andrea Bilbow
    ADDISS

    Previous research looking at the brains of people with ADHD had uncovered differences in areas controlling attention and hyperactivity.

(HealthDay News) — The trouble concentrating that affects people with attention-deficit hyperactivity disorder (ADHD) might be related to motivation, a new study has found.

The motivational problems seen with the condition, which is often associated with children but can persist into adulthood, appear to stem from a reduction in dopamine, an important neurotransmitter in the nervous system that is considered a hallmark of ADHD.

“ADHD is traditionally a disease where people think the disruption is in attention and hyperactivity,” said Dr. Nora D. Volkow, director of the U.S. National Institute on Drug Abuse and lead researcher on the study. “So, the whole focus on research and treatment has been on attention — with kids who cannot pay attention or are hyperactive.”

Classic symptoms of attention deficit hyperactivity disorder, including inattention and the lack of impulse control, might be caused by a disruption of a chemical in the brain that helps cells communicate, a U.S. study suggests.

Studies have already indicated that dopamine, a neurotransmitter needed for normal functioning of the central nervous system, is disrupted in some pathways of the brain in people with ADHD.

A problem in the brain’s reward center may be behind symptoms like inattention associated with attention deficit …

BERKELEY, CA (KGO) — Treating attention deficit hyperactivity disorder can be a life-long ordeal, but some researchers believe they may

(Gina notes: An unfortunate headline, but hey, at least they reported the study!)
Hyperactive children have low levels of a brain chemical vital for causing them to pay attention in return for rewards, claim researchers. …
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PRESS RELEASE

Deficits in brain’s reward system observed in ADHD patients

UPTON, NY — A brain-imaging study conducted at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory provides the first definitive evidence that patients suffering from attention deficit hyperactivity disorder (ADHD) have lower-than-normal levels of certain proteins essential for experiencing reward and motivation.

“These deficits in the brain’s reward system may help explain clinical symptoms of ADHD, including inattention and reduced motivation, as well as the propensity for complications such as drug abuse and obesity among ADHD patients,” said lead author Nora Volkow, Director of the National Institute on Drug Abuse and a long-time collaborator on neuroimaging research at Brookhaven Lab.

The study, published in the September 9, 2009, issue of the Journal of the American Medical Association, also has important implications for treatment. “Finding ways to address the underlying reward-system deficit could improve the direct clinical outcome of ADHD, and potentially reduce the likelihood of other negative consequences of this condition,” said study co-author Gene-Jack Wang, chair of Brookhaven’s medical department.

Prior to this study, it was not clear whether people with ADHD had abnormalities in the brain’s dopamine-mediated motivation/reward system. Previous studies were relatively small and may have been complicated by the fact that some ADHD patients had undergone treatments, or had a history of drug abuse or other conditions that can affect the dopamine system.

To strengthen the statistics and control for these factors, the current study looked at 53 adult ADHD patients who had never received treatment and 44 healthy control subjects — all of whom had been carefully screened to eliminate potentially confounding variables.The scientists used positron emission tomography (PET) to measure two markers of the dopamine system — dopamine receptors, to which the chemical messenger binds to propagate the “reward” signal, and dopamine transporters, which take up and recycle excess dopamine after the signal is sent.

Lying in a PET scanner, each patient was injected with a minute amount of a “radiotracer” compound ? a chemical labeled with a radioactive form of carbon and designed to bind specifically to one of the targets. Different tracers were used for each target, and patients were scanned for each at separate times. By detecting the signal from the radiotracers, the PET machine can measure the receptor and transporter locations and concentrations in various parts of the brain.

The results clearly showed that, relative to the healthy control subjects, the ADHD patients had lower levels of dopamine receptors and transporters in the accumbens and midbrain — two key regions of the brain directly involved in processing motivation and reward. In addition, the measurements of dopamine markers correlated with measures of behavior and clinical observations of ADHD symptoms, such as reduced levels of attention as measured by standard psychological tests.

“Our findings imply that these deficits in the dopamine reward pathway play a role in the symptoms of inattention in ADHD and could underlie these patients’ abnormal responses to reward,” Volkow said.

“This pathway plays a key role in reinforcement, motivation, and in learning how to associate various stimuli with rewards,” she continued. “Its involvement in ADHD supports the use of interventions to enhance the appeal and relevance of school and work tasks to improve performance.

“Our results also support the continued use of stimulant medications ? the most common pharmacological treatment for ADHD ? which have been shown to increase attention to cognitive tasks by elevating brain dopamine,” she said.

The findings may also help explain why ADHD patients are more likely than control subjects to develop drug-abuse disorders and conditions such as obesity.

Said Wang: “Other studies from our group suggest that patients who abuse drugs or overeat may be unconsciously attempting to compensate for a deficient reward system by boosting their dopamine levels. Understanding how deficits in the dopamine system contribute to ADHD and finding ways to improve the functioning of the reward system could help mitigate these troubling consequences in the ADHD patient population.”

This research was supported by the National Institute on Alcohol Abuse and Alcoholism Intramural Research Program and by the National Institute on Mental Health. The Office of Biological and Environmental Research within DOE’s Office of Science provides infrastructure support for the radiotracer chemistry and imaging facilities at Brookhaven Lab. Brain-imaging techniques such as PET are a direct outgrowth of DOE’s long-standing investment in basic research in chemistry, physics, and nuclear medicine.

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Please share with your friends and add your comments below!

Gina Pera

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  1. arnold peters’s avatar

    Thanks Gina.
    I am not personally affected by ADHD, but I find neuroscience interesting. My heart goes out to all those that are affected.
    Your post indicates that we already knew that L-DOPA helps increase attention to cognitive tasks, but this large study supports the theory.
    Your post prompted me to look into Dopamine. I did not know that Dopamine deficiency was also related to Parkinson’s Disease.
    I kinda got sidetracked learning about the prediction learning method called Temporal Difference (TD), which is related to ADHD.
    Thanks for all you do to keep us up to date on the latest ADHD information!

    Reply

  2. Gina Pera’s avatar

    Thanks for stopping in, Arnold!

    If I weren’t rushing to speak at several ADHD-related fundraisers, I would try to put this study in context. Perhaps when I return.

    There is a large body of evidence that explains ADHD neurophysiology. But this study by superb scientist Nora Volkow definitely kicks it up a notch.

    gina

    Reply

  3. Treatment ADHD’s avatar

    Personally I think this study is awesome, the people at NIDA are doing a great job with the research. Having ADHD myself I can absolutely understand some of the conclusions from the data after reading the report.

    However I still reluctantly have a problem with calling this abnormal. Even if there is a smaller number of dopamine receptors in people with ADHD symptoms who is to say that this is wrong. I understand that the behavior this difference creates causes problems for people, myself included, but perhaps we havent fully explored the benefits of this difference.

    It reminds me of Pavlov’s Dog and classical conditioning. Perhaps there is a reason not everyone is easily motivated by rewards and punishment. Any type of medication or treatment that would increase the dopamine receptors could easily be used in a retraining or reprograming scenario.

    I know there are more issues here and I would love nothing more than for them to find something which alleviates the damage caused in peoples lives by ADHD. It is important research like this that keeps us moving forward.

    Reply

  4. Gina Pera’s avatar

    I see your point, but I’m not sure that the term “abnormal” has the same meaning for scientists that it has for the rest of us. For scientists, I think it has more to do with data and not with any kind of judgment.

    From what I know of Dr. Volkow (attending several of her lectures, etc.), I think she takes a pretty nuanced view. In other words, she might be the first to agree with you that these “dopamine differences” deserve further study for full implications.

    In the meantime, though, we face a society that is often science-ignorant, so we need solid proof that ADHD-related challenges aren’t all a matter of willpower, etc.

    Interesting times we live in!

    Reply

  5. Alan’s avatar

    Even if ADHD IS a legitimate disorder – which I very much doubt – the behaviour patterns of many of these kids, and the dopamine deficiency, could very well be caused by all sorts of things – ie diet (aspamarte, etc, etc, etc), spending thousands of hours each year from a young age playing computer games, and so on.

    Do any of these kids get a chance to run around and play with their mates and climb trees and do all the things that most kids did years ago. Most of us ate plenty of sweets and drank fizzy drinks etc back then but at least we were able to burn off our energy.

    I just can’t get my head round the idea that kids DIDN’T have ADHD prior to twenty odd years ago and get put on speed as a consequence, and now millions of kids (but mainly only in the US for some strange reason!) supposedly have this mental disorder and are prescribed powerful drugs that make the pharmacuetical companies billions of dollars evey year thank-you-very-much.

    I have no faith whatsoever in a bunch of people who regarded homosexuality as a mental disorder but then withdrew it from their DSM in the 1970s after big protests by the gay community and the political pressure brought to bear on them as a consequence. That’s not medical science, it’s complete farce.

    Reply

    1. Gina Pera’s avatar

      Thanks for your comment, Alan. I sense your concerns are sincere, and you make a good point about being skeptical of an academic body that would declare homosexuality as a mental disorder (but it’s always tricky to judge people and events out of their historical milieu).

      Until recently, psychiatry was largely influenced by practicioners of the non-biological bent. Dysfunctional human behaviors were attributed to everything but biology (and much was blamed on the mother). Today, scientists such as the highly respected Dr. Nora Volkow are helping us to understand that the brain is not only an organ, it is the most vulnerable organ — vulnerable to both genetic and environmental factors that take place before we are even conceived.

      Any student of history can see that brain dysfunction has been with us always. It’s only now that we are understanding its genesis and, hopefully, healing strategies.

      As for kids not having ADHD twenty odd years ago, most certainly they did. I meet and hear from them every day. They are now well into adulthood and often carry significantly burdensome emotional baggage from going undiagnosed for their entire lives. They sincerely wish that someone had mentioned ADHD as a possibility two decades ago. And these are the lucky ones — the ones who didn’t die in car accidents, succumb to substance abuse, drop out of school, or become incarcerated.

      I also meet newly diagnosed adults with ADHD who are in their 50s, 60s, 70s, and even 80s. ADHD has been with us always, it seems. Here is a blog post about a medical textbook from the 1700s that documents the presence of what sounds like ADHD: http://adhdrollercoaster.org/adhd-in-the-news/newsflash-adhd-dates-back-to-1798-at-least/

      As our society becomes more complex and requires more of the so-called Executive Functions (planning, prioritizing, etc.), ADHD often becomes more obvious.

    2. Alan’s avatar

      That should have read ‘aspartame’, of course.

      Reply

    3. Jeff Sterner’s avatar

      I am a 39 year old male who was rampantly hyperactive, impulsive, and rebellious from a very young age. By the late 70s when ADD was a recognized “disorder”, I was having all sorts of difficulties with attention, executive function, and affective events. My mother chose not to treat me with drugs; I know this was a very hard decision, and thus I do not pass judgement on it.

      As a teen, I discovered that tobacco virtually solved my focus/motivation problems, and I used it to get through college. Soon after graduating, I was trying to quit with the help of a doctor and began using Ritalin and subsequently Adderall, both of which had incredible initial effects, albeit dwindling returns with tolerance. They are still somewhat effective today, as evidenced by return of symptoms with drug holidays.

      It seems to me that the most reliable indicator in support of an ADHD diagnosis is when there is a clear positive effect from taking stimulant medications (or nicotine/caffiene for that matter). There are many kids for which they don’t work, or even have a negative effect on attention and/or mood. In these cases, the root cause seems likely to be elsewhere, possibly an ASD or bipolar/affective condition.

      So whether or not ADHD is considered a real “disorder” is largely irrelevant. The differences in brain structure and/or chemistry that are being consistently demonstrated by science in people with the ADHD symptoms are real, and have evolved for a purpose, likely that of the “hunter” archetype, a disposition that is relatively less common in and definately ill-suited for our culture.

      Specific diagnoses for most personality, developmental, and affective conditions are largely meaningless, a posit that is supported by the frequent comorbidity with other diagnoses and the wide discrepanpcy in response to drug therapy exhibited across the patient population.

      The truth is that people having difficulties exhibit a range of symptoms which are a subset of the combined list of symptoms for many if not most of these diagnoses. If drug therapy is to be used, it should be focused on finding the medication that relieves the symptoms most effectively rather than what drugs are used/approved for a given diagnosis and what dx number is reported to the insurance company.

      Jeff

      Reply

    4. Taylor’s avatar

      Alan, I hope that you will reconsider your doubt regarding ADHD. As Gina pointed out, kids of 20 (how about 40+) years ago were told to quit looking out the window, or to stop doodling, or daydreaming, and to clean up their rooms, for heaven’s sakes. There was nothing but running around, skinning knees, and breathing fresher air then than there is today. And parents who were told that their child was very bright, but has trouble staying focused.

      It is a fairly overwhelming experience to find late in life, after some wheels come off for no apparent reason, that, yes, it sounds like you have classic ADD symptoms. Running the video of your life back in time is edifying when it passes moments and instances that — with this new knowledge — you recall for their confusion, bad consequences, or general inexplicability. When I was in my 20′s I visited a high school teacher of mine who allowed as how I had a good mind, but a “lazy mind.” I had no idea what he meant, and immediately put it out of my mind. 30 years later that moment takes on a different meaning.

      Like any other molecule in the body, those in the brain that manage connections that create what we describe as focus, retention, and other qualities are just as susceptible to genetic and environmentally defined attributes as any other.

      Reply

    5. Dylan’s avatar

      Thank you Gina. Regardless of the date, it’s always great to see research confirming the biological basis of ADHD.

      I love your comment about why ADHD wasn’t diagnosed in kids many years back.

      Reply

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