Brown, T. E., Reichel, P. C., & Quinlan, D. M. (2011). Extended time improves reading comprehension test scores for adolescents with ADHD . Open Journal of Psychiatry , 1 (3), 79–87. https://doi.org/10.4236/jsemat.2011.13012

Extended time was examined by permitting a timed test to be administered without time limits, such that participants were permitted to complete all items.

A total of 145 participants, aged 13–18, with attention-deficit hyperactivity disorder (ADHD), participated. Participants were drawn from two ADHD specialty clinics in the Northeast (U.S.), and were pre-screened and so did not have other disabilities such as reading disability.

The Nelson-Denny Reading Test (NDRT) focused on reading comprehension was the primary assessment during which the extended-time accommodation was provided. Reading screening tests included the word attack and word reading scales from the Woodcock-Johnson Achievement Test (WJ-III) or the Wechsler Individual Achievement Test (WIAT-II). The scores were compared with the Verbal Comprehension Index (VCI) of the WISC-IV or the WAIS III.

Participants' VCI scores were in the high-average range, and their Working Memory Index (WMI) and Processing Speed Index (PSI) were lower, in the average range—all of which fits with scores typical of students with ADHD, as these are difficulties in executive functions related to ADHD. On the standard timed NDRT, about 48% of participants failed to attempt all of the vocabulary items, and about 53% of participants failed to attempt all of the reading comprehension items. Participants' NDRT scores without extended-time, on average, were significantly lower than when provided extended-time. Put another way, about 63% of participants' NDRT scores, without extended-time, were within one standard deviation (SD) of their VCI score, and for reading comprehension items, about 43% of the scores were within 1 SD of VCI scores. However, with extended-time, about 73% of participants' (NDRT) vocabulary scores within 1 SD of their VCI scores, and about 78% of participants' (NDRT) comprehension scores were within 1 SD of their VCI scores. Limitations of the study were reported.