Inattentive ADD Treatment Benefit All ADHD Subtypes

For Inattentive ADD the best dose of stimulant medication is a low dose. The adage that is used to treat ADHD-PI is, "Start low and go slow". It turns out that the Inattentive ADD medication recommendations of low dose stimulants may be the best treatment for ADHD Combined type as well! A very interesting study was just completed and published in the March-April edition of the Journal of Learning Disabilities that point to this conclusion.

The researchers of this ADHD study gathered kids that had been diagnosed as Inattentive ADD, Combined type ADHD or Hyperactive/Impulsive ADHD. They then rated each participant's working memory function and behavior and then labeled the study participants as significantly impaired if they had 'cool' (low) working memory function and 'hot' (high) impulsive behavior scores.

We know from many other studies that kids and adults with Inattentive ADD (ADHD-PI) have low impulsive behavior scores and low working memory or executive function scores while the Combined type ADHD kids have high impulsive behavior scores and low working memory scores. After rating the participants they started them of either low dose or high dose Ritalin.

What they found was that the participants who responded the best to any dose of  the ADD stimulant medication were those kids with high impulsive behavior and low working memory scores, the Combined ADHD kids. What was most interesting from this study however was that while the high doses of Ritalin significantly helped the impulsive behavior aspect of the ADHD, the working memory or neuropsychological functioning of all the participants suffered at the high doses of Ritalin.

This is what the authors of the report, entitled Executive impairment determines ADHD medication response: implications for academic achievement, concluded; "Robust cognitive and behavioral MPH response was achieved for children with significant baseline EWM/SR impairment, yet response was poor for those with adequate EWM/ SR baseline performance. Even for strong MPH responders, the best dose for neuropsychological functioning was typically lower than the best dose for behavior. "

What this all means in English is that all our ADHD kids, not just the Inattentive ADD kids would perform better, from a cognitive or executive functioning point of view, on lower doses of Ritalin. What this means from a practical standpoint is that if we want our combined type kids to shine cognitively, we have to figure out another way to manage their impulsive behavior.

The authors conclude that their "Findings offer one possible explanation for why long-term academic MPH (Ritalin) treatment gains in ADHD have not been realized.” Studies such as these will help people with Inattentive ADD because it will give ADHD intervention researchers a stronger motive to find treatments that improve cognitive functioning rather than diminish it for all patients with ADHD not just the Inattentive ADD patients.

Journal of Learning Disabilities, 2011 Mar-Apr;44(2):196-212.
Executive impairment determines ADHD medication response: implications for academic achievement.
Hale JB, Reddy LA, Semrud-Clikeman M, Hain LA, Whitaker J, Morley J, Lawrence K, Smith A, Jones N.
University of Victoria, Canada