Neurocognitive and self-reported psychosocial and behavioral functioning in siblings of individuals with neurodevelopmental conditions: a study using remote self-administered testing

Figures & data

Figure 1. Cohort characteristics from T1 to T2 and variables examined.

Table 1. Characteristics of the participants and their siblings at T2.

Variable	Category	NDC n (%)	Control n (%)	Total N (%)	BF10	Effect Size δ
Participants (N)		64	64	128
Age (years)	Mean (SD) [range]	18.98 (4.44) [11–27]	20.77 (3.82) [11–27]	19.88 (4.22) [11–27]	2.15	−0.37
	11–13 years	10 (15.63)	4 (6.25)	14 (10.94)
	14–17 years	12 (18.75)	3 (4.69)	15 (11.72)
	18–23 years	31 (48.44)	38 (59.38)	69 (53.91)
	24–27 years	11 (17.19)	19 (29.69)	30 (23.44)
Age at diagnosis of NDC sibling	Mean (SD) [range]	9.87 (4.67) [1–20]	-	-
Sex	Female	42 (65.63)	52 (81.25)	94 (73.44)	0.49	−0.26
	Male	22 (34.37)	12 (18.75)	34 (26.56)
Existing diagnoses	At least one self-report mental health diagnosis	42 (65.63)	24 (37.50)	66 (51.56)	3.37	−0.41
Handedness	Right	43 (67.19)	52 (81.25)	95 (74.22)	0.41	0.21
	Left	21 (32.81)	12 (18.75)	33 (25.78)
Country of origin	Australia	64 (100)	64 (100)	128 (100)
Education level (if >17 yrs old)*	No post-school education	7 (16.67)	8 (14.03)	15 (15.15)
	Trade/TAFE qualification	3 (7.14)	9 (15.79)	12 (12.12)
	Undergraduate	28 (66.67)	30 (52.63)	58 (58.59)
	Postgraduate	4 (9.52)	10 (17.54)	14 (14.14)
Parental ethnicity	Caucasian (Australian, European, New Zealand, American)	47 (73.44)	50 (78.13)	97 (75.78)	0.22	0.08
	Asian (Southern, Northern, Central, Eastern)	8 (12.5)	14 (21.87)	22 (17.19)
	Indigenous Australian	9 (14.06)	0 (0)	9 (7.03)
Annual family income	$0–$50k	16 (25)	12 (29.69)	28 (21.88)	0.30	0.16
	$51k-$100k	31 (48.44)	29 (45.32)	60 (46.88)
	$101k+	17 (25.56)	23 (35.94)	40 (31.25)
Parent NDC status	Neither parent with NDC	49 (76.56)	58 (90.63)	107 (83.59)	2.16	−0.38
	One parent with NDC	13 (20.31)	6 (9.38)	19 (14.84)
	Both parents with NDC	2 (3.13)	0 (0)	2 (1.56)
Parental divorce	Parents are divorced	28 (43.75)	12 (18.75)	40 (31.25)	15.11	−0.52
Participants’ Siblings (N)		64	64	128
Age	Mean (SD) [range]	17.98 (5.38) [8–31]	19.31 (4.35)[12–31]	18.65 (4.92) [8–31]	0.76	0.28
Sex	Female	32 (50)	34 (53.13)	66 (51.56)	0.22	−0.05
	Male	32 (50)	30 (46.87)	63 (49.22)
NDCs	ADHD (2 with ID)	12 (18.75)	-	-
	FASD (4 with ID)	14 (21.88)	-	-
	Autism (5 with ID)	17 (26.56)	-	-
	Rett Syndrome (8 with ID)	10 (15.63)	-	-
	Intellectual Disability	11 (17.19)	-	-
NDC severity**	Not at all	7 (7.81)	-	-
	A bit of a problem	20 (31.25)	-	-
	Sometimes a problem	11 (17.19)	-	-
	Often/always a problem	20 (43.75)	-	-

Effect sizes are the standardized mean difference for the posterior probability, δ. BF10s > 3 indicate evidence of group difference. BFs₁₀ between 1/3 and 1 suggest weak evidence for the null hypothesis of no group difference. BFs₁₀ between 1 and 3 are inconclusive and indicate absence of evidence of group difference. ID: intellectual disability. FASD: fetal alcohol spectrum disorder. *Percentages are for those participants aged over 17 (42 NDC, 57 control). **Participants’ ratings of their siblings’ NDC symptom severity.

Table 2. Descriptive statistics and Bayesian Mann–Whitney independent samples T-Tests at T2.

	NDC (n = 64)		Control (n = 64)				95% HDI
Variable	Mean (SD)	Range	Mean (SD)	Range	BF10	δ	Lower	Upper
Self-Report Variables
Negative ER	21.78 (7.00)	5–32	18.31 (4.67)	5–29	14.34	−0.52	−0.88	−0.18
Positive ER	21.25 (6.09)	9–32	24.50 (6.02)	10–34	13.76	0.49	0.16	0.83
Depression	12.13 (3.93)	5–21	9.03 (3.76)	2–18	260.32	−0.69	−1.06	−0.35
Hyp/Imp	3.61 (1.68)	0–8	2.78 (2.04)	0–8	3.01	−0.39	−0.75	−0.06
Attention	6.19 (2.46)	1–10	4.50 (2.71)	0–11	66.19	−0.58	−0.95	−0.24
Anxiety	11.41 (4.30)	1–20	-	2–15	159.09	−0.71	−1.08	−0.35
Autistic traits	6.05 (2.35)	1–10	4.20 (2.15)	1–9	87.61	−0.64	−1.00	−0.30
Sleep	1.95 (0.90)	0–3	1.39 (0.85)	0–3	16.66	−0.54	−0.93	−0.19
BRIEF Shift	14.58 (5.78)	3–23	11.33 (4.00)	1–20	30.50	−0.55	−0.91	−0.21
Neurocognitive Test Scores
K low scores	1.77 (3.03)	0–10	1.28 (1.77)	0–9	958.88	−0.82	−1.21	−0.47
Corsi Span	4.33 (1.11)	2–6	5.00 (0.94)	3–7	21.97	0.55	−0.20	0.90
Corsi Total	5.28 (2.06)	2–9	6.23 (2.16)	2–11	6.29	0.46	0.12	0.80
Corsi Product	24.86 (14.59)	4–54	32.86 (16.95)	8–77	19.54	0.52	0.18	0.86
WCST PE %	24.27 (5.40)	15–35.00	20.91 (3.79)	15–28.33	39.17	−0.58	−0.94	−0.23
WCST NPE %	14.82 (2.12)	8.33–18.33	13.65 (2.57)	8.33–23.33	12.13	−0.49	−0.85	−0.14
WCST MRT	1902.31 (511.24)	1199–3200	1703.50 (534.10)	1198–3019	7.86	−0.45	−0.79	−0.12
SART Om %	2.47 (0.92)	1–5.50	1.91 (0.89)	1–4.50	42.65	−0.61	−0.98	−0.26
SART Comm %	39.19 (9.88)	16–60	33.56 (8.18)	16–52	30.36	−0.53	−0.89	−0.20
SART MRT	417.73 (89.51)	234–609	366.67 (82.92)	210–523	12.80	−0.51	−0.86	−0.17
N-Back Match %	71.78 (5.69)	57–87	76.16 (6.20)	64–90	69.01	0.64	0.29	0.98
N-Back FP %	22.25 (7.37)	10–37	17.92 (5.55)	4–30	53.67	−0.59	−0.95	−0.26
N-Back MRT	527.20 (152.36)	299–902	571.75 (137.17)	367–982	1.40	0.33	0.001	0.66
SST Go MRT	486.94 (39.47)	434–583	468.88 (32.68)	423–545	14.16	−0.50	−0.86	−0.17
SSRT	280.25 (39.07)	226–364	256.44 (31.81)	214–325	72.56	−0.63	−0.99	−0.29
SST Go Acc %	84.29 (3.01)	78.67–90	86.33 (3.08)	79.33–93.33	35.73	0.59	0.25	0.95
SST NG Acc %	48.00 (7.33)	34–62	52.69 (4.91)	42–68	64.75	0.60	0.26	0.94

All p-values <0.01, except WCSTMRT (p=0.03) and N-Back RT (p=0.08). Hedge’s g effect sizes ranging −0.31 to −0.81. Effect sizes are the standardized mean difference for the posterior probability, δ. BF10s > 3 indicate evidence of group difference. BFs₁₀ between 1/3 and 1 suggest weak evidence for the null hypothesis of no group difference. BFs₁₀ between 1 and 3 are inconclusive and indicate absence of evidence of group difference. Attention: attentional difficulties; AutTraits: Autistic traits; Corsi: longest backward Corsi span; ER: emotion reactivity; Hyp/Imp: hyperactivity/impulsivity; MRT: mean reaction time; N-Back FP%: N-Back False Positives percentage; N-Back Match%: N-Back Match percentage; SART Com%: SART commission error percentage; SART Om%: SART omission error percentage; Sleep: sleep problems; SST Go Acc%: SST go trial accuracy percentage; ST NG Acc %: SST no go trial accuracy percentage; SSRT: stop signal reaction time; WCST NPE%: WCST non-perseverative error percentage; WCST PE%: WCST perseverative error percentage.

Figure 2. NDC sibling group Bayesian posterior parameter Plot.

Note.The posterior parameter plot displays included edges (lines) between nodes (circles; variables), being those with a posterior probability of at least 0.5. Blue lines indicate positive associations and red edge negative associations. Edge thickness represents the strength of the posterior probability. The prior density is concentrated around zero for absent edges, with an uninformative prior for present edges; absent edges are reduced to a near-zero value to produce a sparse network (Marsman et al., 2022; Mohammadi & Wit, 2019). Attention: attentional difficulties; AutTraits: Autistic traits; Corsi: longest backward Corsi span; Hyp/Imp: hyperactivity/impulsivity; NBMatch%: N-Back Match percentage; NegReac: negative emotion reactivity; PosReac: positive emotion reactivity; SARTOm%: SART omission error percentage; Sleep: sleep problems; SSRT: stop signal reaction time; WCSTPE%: WCST perseverative error percentage.

Table 3. T1 self-reported variables predicting k low test scores at T2 in the NDC group.

Dependent variable: k number of low test scores
Model Comparison					P(M)	P(M|data)	BFM	BF10	R^2
Negative ER + Sleep					0.006	0.03	5.76	1.00	0.48
Positive ER + Sleep					0.006	0.03	5.68	0.99	0.48
Negative ER + Attention + Sleep					0.006	0.03	4.88	0.85	0.51
Positive ER + Anxiety + Depression + Sleep					0.006	0.02	4.19	0.73	0.53
Positive ER + Anxiety + Sleep					0.006	0.02	4.14	0.73	0.50
Posterior summary of coefficients								95% CI
Coefficient	P(incl)	P(excl)	P(incl|data)	P(excl|data)	BFincl	Mean	SD	Lower	Upper
Intercept	1.00	0.00	1.00	0.00	1.00	3.53	0.28	3.00	4.10
Anxiety	0.51	0.49	0.49	0.51	0.94	0.07	0.10	−0.007	0.32
Depression	0.42	0.58	0.27	0.73	0.53	−0.02	0.07	−0.24	0.07
Neg ER	0.49	0.51	0.44	0.56	0.81	0.03	0.05	−0.02	0.17
Pos ER	0.51	0.49	0.46	0.54	0.84	−0.04	0.06	−0.19	0.01
Shift	0.40	0.60	0.26	0.74	0.53	0.02	0.05	−0.06	0.16
Age	1.00	<0.001	1.00	<0.001	1.00	−0.20	0.07	−0.33	−0.07
Attention	0.51	0.49	0.45	0.55	0.77	0.09	0.14	−0.02	0.42
Hyp/Imp	0.44	0.56	0.29	0.71	0.52	0.04	0.12	−0.08	0.40
Aut Traits	1.00	<0.001	1.00	<0.001	1.00	0.13	0.17	−0.19	0.46
Sleep	0.64	0.36	0.85	0.15	3.20	0.77	0.48	0.01	1.55

All models include age and autistic traits as covariates. Only the most probable five models are presented. Attention: attentional difficulties; AutTraits: Autistic traits; Hyp/Imp: hyperactivity/impulsivity; Neg ER: negative emotion reactivity; Pos ER: positive emotion reactivity; Sleep: sleep problems.

Marsman, M., Huth, K., Waldorp, L., & Ntzoufras, I. (2022). Objective Bayesian edge screening and structure selection for networks of binary variables. Psychometrika, 87(1), 47–82. https://doi.org/10.1007/s11336-022-09848-8

 PubMed Web of Science ®Google Scholar

Mohammadi, R., & Wit, E. C. (2019). Bdgraph: An R package for Bayesian structure learning in graphical models. Journal of Statistical Software, 89(3), 89. https://doi.org/10.18637/jss.v089.i03

 Web of Science ®Google Scholar

Data availability statement

The data that support the findings of this study are available on request from the corresponding author, BW. The data are not publicly available due to information that could compromise the privacy of participants. The analytic code necessary to reproduce the analyses presented in this paper is available on the first author’s OSF page: https://osf.io/u4gaj.