Adults with attention deficit hyperactivity (ADHD) often experience difficulties with declarative memory—the part of human memory responsible for storing and retrieving facts, details, and other discrete bits of information. Poorly functioning declarative memory can result in missed appointments, forgotten tasks, or a generally disorganized life.
In fact, problems with declarative memory are the root cause of many serious life consequences for adults with ADHD. In spite of this reality, relatively little research has gone into how effective certain ADHD treatments are at improving declarative memory. A study in the Netherlands offered some meaningful insight into the effect of Ritalin (methylphenidate) on declarative memory in adults.
The Netherlands study recruited adults with a stable diagnosis of ADHD. To be eligible, their symptoms had to be successfully kept in check by Ritalin and behavioral therapy. As one of the most common medications used in the treatment of this condition, Ritalin is both safe and effective for the majority of people with ADHD. Eighteen adults signed informed consent papers and completed the protocol.
As part of the experimental design, participants were asked to stop taking their daily Ritalin dosage three days prior to the start of testing. On test day, participants received either their usual dose of Ritalin or a placebo substitute. The setup of the test featured a graphic display of words that flashed briefly on a screen. Fifteen words appeared for several seconds a total of five times. Immediately following this portion of the test, participants were asked to write down all of the words they remembered immediately. They were asked again two hours later, as a means to gauge “delayed recall.”
At the two-hour mark, a list was also presented with fifteen of the displayed words and fifteen “distractors.” By way of push-button controls, participants selected the words they believed were in the original list. This multiple choice test is known as “priming,” and researchers expected that participants would score better on this than the delayed recall test.
As expected, immediate recall was roughly the same between both groups. Delayed recall, however, revealed significant differences. Participants in the Ritalin group scored much better on the delayed recall test than their placebo counterparts. This represents clear evidence that declarative memory is positively influenced by Ritalin. Researchers have not completely mapped out the precise mechanism of Ritalin. The best working theory is that the medication enhances dopamine levels in regions of the brain associated with memory formation, storage and recall. Future research may identify substances that achieve this result without the added effects of psychostimulants.
- Attention deficit hyperactivity disorder (ADHD) – PubMed Health. (n.d.). National Center for Biotechnology Information. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002518/
- Verster, J.C., Bekker, E.M., Kooij, J.J., Buitelaar, J.K., Verbaten, M.N., Volkerts, E.R., & Olivier, B. (2010). Methylphenidate significantly improves declarative memory functioning of adults with ADHD. Psychopharmacology, 212, 277-281.
© Copyright 2011 by James Pendleton. All Rights Reserved. Permission to publish granted to GoodTherapy.org.
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