TABLE 4.

Effect ADHD on ASD outcome in NF1.

ADHD instrument	ASD instrument	Reported relationship between ADHD and ASD	Authors and year
CPRS‐R, CTRS‐R	ADI‐R, ADOS‐G	Equal ADHD symptoms in NF1+ASD, NF1+bASd, and NF1 without ASD	Garg, Green, et al. (2013)
CPRS‐R	SRS	Using SRS cut‐off ≥60: 40.3% ASD+ADHD and 18.2% ASD without ADHD Using SRS cut‐off ≥76: 25% ASD+ADHD and 4.8% ASD without ADHD	Garg, Lehtonen, et al. (2013)
VADPRS/taking stimulant medication	SRS	In NF1+ADHD significantly more often total T score, social cognition, and social communication >60 than in NF1‐ASD	Walsh et al. (2013)
Conners‐3, CAARS	SRS	Moderate positive correlation between SRS total T score and ADHD measures, but different distribution	Constantino et al. (2015)
CAARS, CADS, Conners‐3, CPRS	SRS	Moderate positive correlation between SRS total T score and ADHD measures, but different distribution and sex ratio	Morris et al. (2016) a
ADHD‐RS4	SRS	Using SRS cut‐off ≥76: 18.9% ASD+ADHD and 1.8% ASD without ADHD	Hirabaru and Matsuo (2018)
CADS, Conners‐3	SRS, SSIS	Moderate positive correlation between SRS total T score and both Inattention and Hyperactivity/impulsivity	Payne et al. (2020)
CBCL	SRS	Significant positive correlation between SRS and CBCL ADHD subscale 30% of SRS difference between NF1 and TD accounted for by CBCL ADHD In the regression model CBCL ADHD, CBCL Internalizing, and Vineland Communication significant predictors of SRS score, but not NF1/TD group status	Morotti et al. (2021)
CPRS, Conners‐3	SSRS, SSIS	Hyperactivity and inattention in early childhood negatively correlated with social skills in early childhood Both inattention in early childhood and hyperactivity and inattention at school age negatively correlated with social skills at school age	Glad et al. (2021)
CADS, Conners‐3	SRS, ADOS‐2, ADI‐R	Both hyperactivity/impulsivity and inattention weak to moderately positively correlated with SRS total T scores Hyperactivity/impulsivity weakly positively correlated with ADI‐R scores No correlations between ADHD symptoms and ADOS‐2 scores	Chisholm et al. (2022)
VABS‐II, DSM‐IV‐TR	SCQ	All participants screening positive on the SCQ had a diagnosis of ADHD	Cohen et al. (2022)
SDQ	SEARS‐P	Higher hyperactivity/inattention predictive of both lower social competence and lower empathy	Foy et al. (2022)
CADS, Conners‐3	SSIS	Moderate to strong intercorrelations between social skills, ADHD symptoms, and executive functions ADHD symptoms mediate the relationship between executive functions and social skills	Haebich et al. (2022)

Abbreviations: ADHD‐RS4, ADHD Rating Scale 4; ADI‐R, Autism Diagnostic Interview‐Revised; ADOS‐G, Autism Diagnostic Observation Schedule‐Generic; CAARS, Conners Adult ADHD Rating Scale; CADS, Conners ADHD/DSM‐IV Scales; CBCL, Child Behavior Checklist; Conners‐3, Conners parent report form; third edition; CPRS‐R, Conners Parent Rating Scale–Revised; CTRS‐R, Conners Teacher Rating Scale‐Revised; NF1+ASD, only NF1 participants preselected on ASD; NF1+bASD, only NF1 participants preselected on broader ASD, excluding ASD itself; NF1‐ASD, only NF1 participants without ASD; SDQ, Strengths and Difficulties Questionnaire; SRS, Social Responsiveness Scale; TD, Typically developing; VABS‐II, Vineland Adaptive Behavior Scales‐2nd edition; VADPRS, Vanderbilt ADHD Diagnostic Parent Rating Scale.

^a Pooled original data with those from Garg, Lehtonen, et al. (2013)³⁹, Walsh et al. (2013)³¹, Adviento et al. (2014)²⁵, Constantino et al. (2015)²⁷, and Plasschaert et al. (2015)¹⁰.