Sluggish Cogntive Tempo and Arousal Levels in ADHD

Arousal and Sluggish Cognitive Tempo
It is estimated that 30% to 50% with the Inattentive subtype of ADHD (ADHD-PI) also have problems with slow cognitive processing. A Slow cognitive processing speed can affect a person’s ability to pay attention, to learn, to remember and to interact socially.

Cognitive processing speed refers to the time that it takes for a person to take in and respond to information that they receive visually, or from auditory, motor or tactile stimuli. Cognitive speed increases as a person ages and peaks in adolescence or young adulthood.

Picture a Kindergarten classroom of twenty-six kids. They are all supposed to be listening to the math lesson. Eighteen kids in the class are busily listening and following along in their books, three kids in the class are busily and quietly doing something else, three kids in the class are wandering around being disruptive, one child is bouncing off the walls and one child is sitting quietly staring out the window.

The child staring out the window is a very low priority for this teacher. He may even do well enough on math tests for the next several years and avoid anyone noticing that this child has a problem processing information. Once you know what this type of child looks likes like, they are amazingly easy to spot.

Someone said that “even the school janitor can diagnose the kid with Hyperactive/Impulsive ADHD”, the contention is true that it’s the Inattentive subtype that can be difficult to spot. I would argue, however, that once you know what to look for, children with SCT stand out in the classroom like a sore thumb.

Many people with ADHD-PI and Sluggish Cognitive Tempo (SCT) will appear to be under aroused. In a classroom or on the playground these kids appear as though they are in a daze. They will be unable to sustain focus, they will become bored easily, they will have trouble accessing information in their long-term memory and they will perform tasks in a much slower and inefficient manner than people with normal cognitive processing speeds.

Though the person with Inattentive ADHD and SCT may exhibit all the deficiencies seen in an under aroused cognitive state, people with the Combined type (ADHD-C) and the Hyperactive/Impulsive subtype of ADHD may have issues with cognitive processing speed as well.

The non-Inattentive subtypes of ADHD may only show symptoms of slow processing in certain areas where they are cognitively weak such as auditory processing. Recognizing these slow processing problems may be more difficult as these people will likely be over aroused or hyperactive in their motor functions.

Cognitive processing speeds improve for everyone as alertness improves and any treatment that improves alertness such as exercise, frequent breaks, rewards, hands-on work, high protein snacks, engaging materials, etc will also improve cognitive speed.

The speed of cognitive processing is important to behavior, social competence and to academic achievement. Arousal levels will affect the speed of cognitive processing and activities and interventions that increase our alertness will also impact on how quickly we are able to process and act on incoming information.


  1. Your blog has been down for a while today and your profile inaccessible. I just found your site yesterday and it is full of information. I was worried today that you dropped off the planet, i am happy to see that was not the case. Keep up the great work!

  2. Alex, I am not sure what happened to it. Google said that there had been suspicious activity and I had to set up a new password. I am glad that you found us and thank you for your kind comments!

  3. I would like to find out more about SCT..
    My best friends (who are less intelligent than me.. no offense to them) have called me "slow" ever since I can remember. I learned to laugh along with it and I think that has allowed me to have a very laid back personality. When I was diagnosed with ad/hd my junior year of college, I felt like I finally had a reason why I was so smart but also so much slower than anyone else around me.
    I was in a college final exam bootcamp (with I assume mostly other ad/hd students). I felt like I could relax with my brethren. Imagine my dismay when one of the girls there looked at me like I was an idiot because once again I was being "slow" and didn't respond to her question like she expected.

  4. Tess I have a question. I heard that studies seemed to show that SCTers do not respond well to Methylphenidates. I have heard SCTers may respond well to amphetamines, but I have not been able to find any studies on that. Do you know of any studies that verify this or any studies that have shown certain medications to be beneficial for SCT/ADHD-I?

  5. John, On the left side of this blog where the big letters say "Research References" (Under those gorgeous member pictures) there is an article by Adele Diamond PhD where she talks about Adderall vs Ritalin for ADHD-PI. It is estimated that about 50% of people currently diagnosed with ADHD-PI will move into the SCT category so the research that Dr. Diamond is talking about is where the information that you heard comes from. I hope this helps.


