Seems everyone has an opinion about the causes and treatments of attention deficit hyperactivity disorder (ADHD). And the Centers for Disease Control (CDC) publishes some provocative statistics on ADHD including, as of 2007, 2.7 million youth ages 4-17 years (66.3% of those with a current diagnosis) were receiving medication treatment for the disorder. ADHD is also remarked on the list of mental health issues for violent deaths in a 2007 CDC surveillance report covering sixteen states in the U.S.
Parents and researchers will find a useful summary of numerous ADHD treatments and research is coming out in the August 2011 issue of Pharmacology, Biochemistry, and Behavior. If you are a parent or researcher for ADHD, this article is chock-full of information and the reference list is golden, covering over 200 academic and professional sources.
In order to understand and treat ADHD, researchers emphasize the importance of understanding what parts of the brain and thinking processes are involved. The article walks through the definition of the cognitive or brain thinking activities associated with ADHD. They weigh in on several types of FDA-approved medicines being used, several non-FDA approved agents or substances that have been tried, and some alternative non-drug intervention methods.
Defining ADHD
Bidwell et al discuss the "executive functions (EFs)" of the brain citing a theory that ADHD is essentially a symptom arising "from a primary deficit in those functions." EFs appear to include the brain processes in human thinking where, given what we know, we weigh our options and decide how we will react moment by moment. Many areas of the brain are engaged to complete this processing.
Some ADHD Behaviors
Researchers listed the following cognitive difficulties that may be associated with ADHD:
- learning from mistakes,
- delaying gratification,
- and ability to weigh short and long term benefits of a choice.
Treating ADHD
In order to assess the success of a treatment, studies include applying the treatment and observing the physical and mental impacts afterwards. Researchers try to find evidence of improvement or identify negative reactions possibly caused by the treatment. The more cognitive symptoms a treatment appears to positively improve, the more it is favored.
Highlights of Drug Treatments Reviewed
Stimulants
As counter-intuitive as it may seem, Bidwell et al advise that stimulant drugs have been studied and prescribed for ADHD patients since the 1960s, e.g., methylphenidate and amphetamine. Their article offers some explanation for this practice. However, in consideration of more recent research, they report that stimulants have not been consistently shown to reduce ADHD behaviors or sustain improvement in patients' academic achievement over time.
Non-stimulants
According to the researchers, Atomoxetine (ATX) was approved in 2002 as the "first non-stimulant drug" for ADHD. However, they advise that much more research is needed before ATX is declared victorious in their opinion, noting that while it may be beneficial, research may show evidence of ATC improving only select brain functions.
Alpha 2 Agonists
Clonidine and guanfacine are mentioned as treatments that have been prescribed for more than two decades. They are considered "alpha 2 agonist" drugs. Bidwell et al explain that these drugs have been considered "off-label" therapy until a couple of them were approved by the FDA starting in 2009. And the researchers advise that while showing some strength in improving cognitive functions in animals and humans, they do not believe the results for alpha 2 agonists have been "entirely consistent across human studies" and call for more research.
Nicotine
Studies on nicotine-based treatments have been explored recently. Bidwell et al note earlier research including that ADHD patients begin smoking at an earlier age and find it difficult to stop. They seem to feel these practices point to some inherent benefit is being sought from nicotine. Any such cognitive benefit specific to ADHD was not confirmed, but based on the results of some studies, nicotine-based treatments may be emerging. This article did not address concerns for any suspected side effects from such nicotine-based treatments, e.g., possibly harmful in pregnancy, or whether FDA approval for ADHD is likely.
Modafinil
Modafinil was mentioned as a "stimulant-like" drug currently approved for use in treating narcolepsy. However, Bidwell et al report that there is considerable controversy in using modafinil and other "wake-promoting" agents, and they feel it likely will not be approved for ADHD, to be determined.
Alternative Treatments Reviewed
Turning to non-drug type solutions, the article touched on two additional treatment methods that have been explored: computer-based working memory training and neuro-feedback.
Working Memory
Bidwell et al described some memory exercise research that appears to have promise. ADHD children were given memory-based exercises by computer training for short periods over several weeks. They report favorable results to date and look forward to several active trials going on. Information about these trials is available on the U.S. government's clinical trials website if searched under the terms ADHD cognitive training.
Neurofeedback
Neurofeedback involves a type of video or computer-based formatted activity. Bidwell et al acknowledge that neurofeedback is controversial, appears favored by parent and teacher feedback, and this experimental treatment is the focus of several active clinical trials similar to the working memory training.
Conclusion
All in all, the Bidwell team believes that further investigation in cognitive-enhancing drugs for ADHD is warranted. Such shadowed endorsements are considered helpful to spur on future research in the medical field. They emphasized the importance of understanding the cognitive processing involved in ADHD and targeting drug research to address those specific symptoms. Their article provides an invaluable documentation trail for independent investigation.
Note: One member of the research team disclosed that research funding and/or consulting fees have been provided by pharmaceuticals, foundations, and corporate sponsorship (Philip Morris USA).
Special thanks to Dr. Scott H. Kollins, Director ADHD Program, Duke University, who provided additional information to support this article review.
Disclaimer: The information and links contained in this article are for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact a licensed medical doctor for advice.This is an editorial review only. Readers should refer to original cited sources to ensure accuracy and for any interpretation of source material.
Other articles related to research for illness in children by Melanie Hundley include: New Research: Police Work and Autism, New Research: Asperger Syndrome and Depression, New Research: Type 1 Diabetes Increases in Young Children and Could My Severely Disabled Child Ever Get a Job?
Sources
- Amir, O. (2008, July 22). Tough choices: how making decisions tires your brain. Scientific American (online). Retrieved July 13, 2011, from corporate website.
- Bidwell, L., McClernon, F., & Kollins, S. H. (2011). Cognitive enhancers for the treatment of ADHD. Pharmacology, Biochemistry & Behavior, 99(2), 262-274. Retrieved July 12, 2011, from EBSCOhost online database. DOI:10.1016/j.pbb.2011.05.002.
- Centers for Disease Control & Prevention. (2010, November 10). Attention-deficit/hyperactivity disorder (adhd): status and statistics. Retrieved July 13, 2011, from government website.
- Centers for Disease Control & Prevention. (2010, May 14). Surveillance for violent deaths. Retrieved July 13, 2011, from government website.
- Dictionary.com. (2011). Cognitive. Retrieved July 13, 2011, from online corporate website.
- Dingfelder, S. (2005, September). A workout for working memory. Monitor on Psychology, Vol 36, No.8). Retrieved July 13, 2011, from American Psychological Association website.
- Drugs.com. (2009, November 18). Nicotine. Retrieved July 13, 2011, from corporate website.
- Ellison, K. (2010, October 4). Neurofeedback gains popularity and lab attention. NY Times. Retrieved July 13, 2011 from corporate website.
- U.S. National Institutes of Health. Clinical trials.gov. Retrieved July 13, 2011, from registry and results database on government website.
- U.S. National Library of Medicine. (2010, August 1). Amphetamine. Retrieved July 13, 2011, from PubMed Health online database.
- U.S. National Library of Medicine. (2008, September 1). Atomoxetine. Retrieved July 13, 2011, from PubMed Health online database.
- U.S. National Library of Medicine. (2011, April 11). Attention deficit hyperactivity disorder. Retrieved July 13, 2011, from PubMed Health online database.
- U.S. National Library of Medicine. (2010, October 1). Clonidine. Retrieved July 13, 2011, from PubMed Health online database.
- U.S. National Library of Medicine. (2010, February 1). Guanfacine. Retrieved July 13, 2011, from PubMed Health online database.
- U.S. National Library of Medicine. (2011, January 1). Methylphenidate. Retrieved July 13, 2011, from PubMed Health online database.
- U.S. National Library of Medicine. (2008, September 1). Modafinil. Retrieved July 13, 2011, from PubMed Health online database.
- U.S. National Library of Medicine. (2009, September 2). Narcolepsy. Retrieved July 13, 2011, from PubMed Health online database.
