The Invisible ADD Subgroup Robert D. Smith,PhD Sluggish Cognitive Tempo (SCT) is an unofficial descriptive term, which identifies a unique subgroup within the officially recognized diagnosis of ADHD Predominantly Inattentive Type. It has been estimated that the SCT group makes up 30-50% of the ADHD-PI population. Instead of being hyperactive and extroverted the SCT group is passive, daydreamy and shy. They are sluggish and in a fog. They appear to lack motivation. Those with SCT have difficulty with verbal retrieval from long term memory. They have deficits in working memory which has been described as the ability to keep multiple things in mind for manipulation, while simultaneously keeping this information free from internal distraction. Consequently, mental skills such as calculation, reading, and abstract reasoning are often more challenging for those with SCT. They also have a more disorganized thought process, a greater degree of sloppiness, and lose things easily. Since the symptoms of SCT are not recognized in any standard medical manuals, they receive an ADHD/PI diagnosis. Sluggishness, drowsiness, and daydreaming were the characteristics originally listed in early versions of the DSM. These criteria were eliminated because of erroneous preconceptions about the nature of ADHD and are now under revision for the next version of the Diagnostic and Statistical Manual. They tend to have a greater degree of learning disabilities, such as dyslexia. Instead of having greater difficulty selecting and filtering sensory input, as is in the case of SCT, people with other types of ADHD have problems with inhibition. Ritalin is often still the first treatment tried, but medications such as Adderall are often more effective. However, cognitive attention training may be an effective alternative to those who do not respond to or cannot tolerate the side effects of medication Attention Deficit Disorder Otherwise Known as Attention Deficit Hyperactivity Disorder, Predominanlty Inattentive Presentation