Social Cognition Results
Results from the first one-way ANCOVA revealed significant group differences for total TASIT score [F (4, 268) = 30.912, p<.01]. Post-hoc pairwise comparisons revealed that all groups obtained significantly higher total TASIT scores compared to the 22q11DS group [22q11DS<CHR: (t(96) = -7.991, p<.01); 22q11DS<FEP: (t(97) = -3.346, p<.01); 22q11DS<ASD: (t(72) = -4.497, p<.01); 22q11DS<HC: (t(150) = -12.528, p<.01)]. Additionally, FEP and ASD groups obtained significantly lower total TASIT scores than the HC group (Figure 1A) [HC>FEP: (t(149) = 5.459, p<.01); HC>ASD: (t(124) = 4.306, p=.01)]. Follow-up one-way ANCOVAs revealed that the 22q11DS group obtained significantly lower scores across all four subdomains of the TASIT compared to all other groups [Figures 1B-1E]. Additionally, the FEP group obtained significantly lower Do and Say scores than HCs (Figure 1B, 1C). The 22q11DS group obtained significantly lower Think scores than CHR, ASD, and HC groups, but did not differ from the FEP group, who in turn performed more poorly than the HC group (Figure 1D). Additionally, the FEP group obtained significantly lower Feel scores than the HCs (Figure 1E). See Table 2 for means and standard deviations on TASIT total and subscores for each group.
Intellectual Functioning (IQ) Results
Next, one-way ANCOVAs of WASI-II FSIQ scores revealed a significant overall main effect, indicating significant group differences in FSIQ [Figure 2; F (4, 265) = 52.106, p<.01]. Post-hoc tests revealed that 22q11DS individuals obtained significantly lower FSIQ scores compared to all other groups [Figure 2A], and the FEP group obtained significantly lower FSIQ scores than both CHR, ASD, and HC groups. Significant group differences were also observed for VIQ [F (4, 265) = 46.106, p<.01], with 22q11DS individuals obtaining significantly lower VIQ scores compared to all other groups (Figure 2B). Additionally, the FEP group obtained significantly lower VIQ scores than both CHR and HC groups (p<.01 for both comparisons), but did not differ from the ASD group (p=.50, n.s.). Similarly, 22q11DS individuals obtained significantly lower NVIQ scores than all other groups [F (4, 233) = 45.635, p<.01; Figure 2C]. Additionally, youth with FEP obtained significantly lower NVIQ scores than those with ASD (Figure 2C), but did not significantly differ from HC (p=.12, n.s.). See Table 3 for means and standard deviations of WASI-II IQ scores for each group.
Social Cognition Performance Controlling for IQ
A follow-up univariate ANCOVA revealed that significant group differences in TASIT performance remained after controlling for IQ [Figure 3; F (4, 264) = 7.471, p<.01]. Specifically, after controlling for FSIQ, 22q11DS participants still had significantly poorer performance on the TASIT (total score) relative to FEP and HC, but did not differ from CHR (p=.66, n.s.) and ASD (p=.89, n.s.; Figure 3A). Additionally, controlling for FSIQ, FEP participants still had significantly lower TASIT total scores than CHR, and ASD participants had significantly lower TASIT total scores than CHR and HC (Figure 3A). Next, we wanted to determine whether controlling for VIQ or NVIQ specifically impacted TASIT performance across groups. After controlling for VIQ, significant group differences in TASIT performance remained [F (4, 264) = 6.119, p<.01], with 22q11DS individuals obtaining significantly lower TASIT total scores than CHR and HC groups, but did not differ from FEP (p=.48, n.s) and ASD group (p=.61, n.s.; Figure 3B). Additionally, significant between-group differences in TASIT performance was also observed after controlling for NVIQ [F (4, 232) = 10.099, p<.01], with 22q11DS individuals obtaining significantly lower TASIT total scores than CHR, FEP, and HC groups, but not compared to the ASD group (p=.72, n.s.). The ASD group also obtained significantly lower TASIT total scores than both CHR and HC groups, controlling for NVIQ (Figure 3C).
Relationship between Social Cognition Performance and IQ
Pearson’s correlation results indicated positive relationships between TASIT total score and FSIQ as well as VIQ for all groups, such that higher intellectual functioning was associated with better TASIT performance in each group (Figure 4A, 4B). Lastly, we found significant positive correlations between TASIT and NVIQ for all groups, except ASD (Figure 4C).
Reciprocal Social Behavior
Results from the one-way ANCOVA revealed significant group differences in SRS total score across groups [Figure 5A; F (4, 140) = 9,861 p<.01]; HC participants obtained significantly lower SRS total scores compared to all other groups, indicating more normative social behavior (p<.01, for all comparisons), except CHR (p=.07, n.s.). While clinical groups (22q11DS, CHR, FEP, and ASD) obtained clinically elevated mean SRS total scores, there were no significant differences in SRS score between clinical groups (Supplementary Table 1). Lastly, we examined the relationship between TASIT performance and real-world social behavior, as assessed via the SRS, for each group. However, no correlations between these measures survived correction for multiple comparisons (Figure 5B). We also ran an exploratory analysis examining the association between SRS subscale scores and TASIT total score for each group, and did not find any associations between subscale scores and TASIT performance that survived correction for multiple comparisons (Supplementary Table 2).
22q11DS Subgroup Analyses
Within the 22q11DS sample, we found significant differences in VIQ [F (3, 45) = 4.743, p=.01], and relatedly FSIQ [F (3, 45) = 3.397, p=.03], as a function of psychiatric diagnosis, but no differences in NVIQ (p=.29, n.s.). Specifically, 22q11DS patients with both psychosis and ASD obtained significantly lower VIQ (and FSIQ) than the 22q11DS group with no comorbid diagnosis. Intellectual functioning (FSIQ, VIQ, and NVIQ) did not differ between 22q11DS group with no comorbid diagnoses compared to those with psychosis-only diagnosis, nor those with ASD-only diagnosis (p>0.9, n.s., for all comparisons). No significant differences in TASIT total score [F (3, 46) = 1.890, p=.15] and SRS total score [F (3, 42) = 2.894, p=.09] were observed as a function of ASD/psychosis comorbidity in 22q11DS. See Table 4 for means and standard deviations of TASIT, WASI, and SRS scores for each subgroup.