Mental Health and Cognitive Outcomes in High-Risk Infant Siblings Followed Longitudinally to Ealry Adolescence: Patterns and Predictors
Objectives: To examine mid/late childhood/adolescent mental health and cognitive outcomes, and predictors thereof, in a HR sibling sample.
Methods: We re-assessed 117 HR siblings (72 boys; 45 girls; M age = 9.6 years; range = 7.7-13.6), followed from age 6 or 12 months, to examine later mental health and cognitive outcomes. Based on blinded clinical best-estimate assessment, 41 met criteria for a diagnosis of ASD (76 = non-ASD). Variables analyzed included: (1) early temperament (Toddler Behavior Questionnaire; TBQ, at age 2) and cognition (Mullen Scales of Early Learning; ages 1 and 2), and (2) mid-to-late childhood/adolescent mental health (Child Behavior Checklist, Ages 6-18; CBCL) and cognition (WISC-V).
Results: (1) Mental Health Outcomes: High-risk siblings with and without ASD experienced high rates of parent-reported symptoms on the CBCL, with > 10% of both Non-ASD and ASD sub-groups experiencing symptoms in the clinical range (T-scores > 90th %ile) in Internalizing (17.1%; 35.1%) and Externalizing (14.3%; 35.1%) areas, with groups differing only in rate of Externalizing symptoms (p = .007). Elevated rates of clinically concerning (i.e., borderline or clinical range) problems were reported for siblings with both non-ASD and ASD outcomes for Anxious/Depressed (12.9%, 27%), Withdrawn/Depressed (11.4%, 33.4%), Somatic Complaints (12.8%, 16.2%), and Aggressive Behaviour (14.3%, 33.2%). Elevated DSM-oriented scales included Affective (12.9%, 37.8%), Anxiety (14.2%, 37.8%), Somatic (11.6%, 13.5%), Oppositional (12.9%, 27%), and Obsessive-Compulsive (12.8%; 29.7%) scales. TBQ Attention Shifting at age 2 predicted later Internalizing (R2 = .08; p =.006) and Externalizing Problems (R2 = .07; p =.009). (2) Cognitive Outcomes revealed mean WISC-V index scores within average limits for both groups, who differed only on the Processing Speed Index (PSI; Non-ASD M = 99.9; ASD M = 87.0; p =.001). The strongest predictor of PSI performance was age 2 Mullen Visual Reception (VR; R2 = .12 for Non-ASD; p = .02 and R2 = .36 for ASD; p = .006), with a trend toward 12-month Mullen VR as a predictor (both group p’s = .07). For both groups, 2-year Mullen Receptive (RL) and Expressive Language (EL) significantly predicted later Verbal Comprehension Index (VCI); p’s < .02. Notably, RL (R2 = .49) was more informative than EL (R2 = .28) for the ASD group, whereas the opposite pattern was seen in the Non-ASD group (R2 = .13 and R2 = .27 for RL and EL, respectively).
Conclusions: Findings reveal mental health challenges commonly encountered by siblings of children with ASD, regardless of their own ASD outcomes. High rates of mental health challenges, despite average cognitive functioning, highlight the importance of monitoring the mental health of these HR children into middle childhood and beyond. Results highlight the potentially informative roles of temperament and both nonverbal and language abilities in early life in predicting later outcomes.