Neurocognitive Functioning in AD/HD, Predominantly Inattentive and Combined Subtypes

Sluggish cognitive tempo and its neurocognitive, social and emotive correlates: a systematic review of the current literature

“…It has to be questioned whether behavior observations reliably reflect slow processing speed or whether reductions of processing speed are better depicted by actual assessments using psychometrically valid information processing tasks, such as reaction time measures, visual search- and pattern recognition tasks, or perceptual timing tasks. Experimental data indeed confirmed that children with ADHD/I and SCT presented with a slower task accomplishment during the Tower of London Task (ToL) and higher mean reaction times in the Continuous Performance Test [ 31 , 40 ]. The authors concluded that children with ADHD/I and SCT do not present with inaccurate performance but do perform neurocognitive tasks in a conspicuous slow tempo [ 31 ].…”

“…Experimental data indeed confirmed that children with ADHD/I and SCT presented with a slower task accomplishment during the Tower of London Task (ToL) and higher mean reaction times in the Continuous Performance Test [ 31 , 40 ]. The authors concluded that children with ADHD/I and SCT do not present with inaccurate performance but do perform neurocognitive tasks in a conspicuous slow tempo [ 31 ]. It has therefore been hypothesized that SCT does not affect the underlying cognitive function per se (e.g., EF, inhibitory control) but compromises the overall task performance by slowing down task related processes [ 31 ].…”

“…Only one study looked into SCT in adults with ADHD, examining hereby the association between self-rated SCT and executive functioning [ 16 ]. Initially, SCT was represented by four items (“difficulty following instructions”, “sluggishness”, “drowsiness”, “absent-minded, forgetful” [ 28 ]) that were then either reduced to two (“daydreams”, “is low of energy” [ 12 , 17 , 29 – 31 ]) or expanded up to 17 items in more recent studies [ 19 , 32 , 33 ].…”

“…To conclude, even though various scales have been shown to effectively measure SCT [ 16 , 31 , 36 ], a standard of measurement across studies is not yet achieved. Moreover, some evidence points into the direction that even though SCT items might identify individuals with SCT [ 2 , 11 , 14 ], their contribution in distinguishing subtypes of ADHD should be questioned [ 13 , 30 ].…”

“…Independent of the number of items that were used to represent SCT, “daydreaming”, “sluggish/drowsy” and “underactive/apathetic” were items that consistently contributed to the identification of SCT in children [ 2 , 11 , 14 , 19 ] and adults [ 16 ]. More in detail, the item “daydreaming” was represented in all studies reviewed [ 23 , 27 , 29 , 34 ] followed by “sluggish/drowsy” [ 16 , 30 , 31 , 36 ] and “underactive/apathetic” [ 11 , 16 , 23 , 37 ]. Future research could use these three items as a baseline measurement for SCT without missing out to assess their individual link to behavioral and neurocognitive correlates.…”