Sleep disorders and executive-function inefficiency in boys with intellectual disabilities: A cross-sectional comparative study.

Objectives

This study compared caregiver-rated sleep symptom scores and executive-function task performance in boys with intellectual disabilities (ID) and age-matched typically developing (TD) boys and examined associations between the total sleep-disorder score and executive-function outcomes within the ID group.

Methods

A cross-sectional comparative-correlational design was used. The final sample comprised 50 boys aged 5-13 years: 25 with ID and 25 TD controls. Intellectual functioning in both groups was assessed with the Arabic adaptation of the Stanford-Binet Intelligence Scales, Fifth Edition (SB5). Caregivers completed a 40-item Arabic sleep-disorder rating scale, and children completed a researcher-adapted battery assessing working memory, planning completion time, response inhibition, and sustained attention. Group differences were examined with Mann-Whitney U tests with rank-biserial effect sizes, and within-ID associations were examined with Spearman rank correlations with Holm adjustment for four comparisons. All analyses were computed from the complete participant-level dataset (N = 50).

Results

The ID group had a higher total sleep-disorder score than the TD group (U = 624.5, z = 6.06, p < .001, rank-biserial r = 0.998) and higher scores on each of the four sleep subscales (all p < .001). The ID group also performed more poorly on all four executive-function tasks (all p < .001). Within the ID group, higher total sleep-disorder scores were associated with lower working-memory scores (ρ = -0.82), longer planning completion time (ρ = 0.71), lower response-inhibition scores (ρ = -0.74), and lower sustained-attention scores (ρ = -0.51). All four associations remained significant after Holm correction (adjusted p ≤ .01).

Conclusions

Caregiver-rated sleep-disorder scores were higher in boys with ID than in TD peers, and within the ID group they were associated with weaknesses in executive functioning. Given study limitations, the findings should be considered as preliminary; larger studies using independently validated measures are needed.