Rai D, et al. - In order to assess associations between autism spectrum disorders (ASD) and autistic traits and an International Statistical Classification of Diseases, 10th Revision (ICD-10) depression diagnosis at age 18 years and to determine the significance of genetic confounding and bullying, researchers performed a comparison of trajectories of depressive symptoms from ages 10 to 18 years for children with or without ASD and autistic traits. Compared to the general population, children with ASD and ASD traits showed higher depressive symptom scores by age 10 years, which continue to age 18 years, especially in the context of bullying. In relation to depression, social communication impairments were noted to be an important autistic trait. They suggest implementing interventions targeting bullying.

Methods

• Researchers performed a longitudinal study of participants in the Avon Longitudinal Study of Parents and Children birth cohort in Bristol, UK.
• Participants were followed up through age 18 years.
• From January to November 2017, they performed data analysis.
• Using the Short Mood and Feelings Questionnaire (SMFQ), they assessed depressive symptoms at six time points between ages 10 and 18 years.
• Using the Clinical Interview Schedule–Revised, they established an ICD-10 depression diagnosis at age 18 years.
• Exposures included ASD diagnosis and four dichotomized autistic traits (social communication, coherence, repetitive behavior, and sociability).
• They used the Psychiatric Genomics Consortium autism discovery genome-wide association study summary data to derive an autism polygenic risk score.
• They assessed bullying at ages 8, 10, and 13 years.

Results

• The maximum sample with complete data was 6,091 for the trajectory analysis (48.8% male) and 3,168 for analysis of depression diagnosis at age 18 years (44.4% male).
• Children with ASD and autistic traits vs the general population at age 10 years showed higher average SMFQ depressive symptom scores (eg, for social communication 5.55 [95% CI, 5.16-5.95] vs 3.73 [95% CI, 3.61-3.85], for ASD 7.31 [95% CI, 6.22-8.40] vs 3.94 [95% CI, 3.83-4.05], remaining high in an rising trajectory until age 18 years (eg, for social communication 7.65 [95% CI, 6.92-8.37] vs 6.50 [95% CI, 6.29-6.71], for ASD 7.66 [95% CI, 5.96-9.35] vs 6.62 [95% CI, 6.43-6.81]).
• In this work, social communication deficiencies were noted to be associated with depression at age 18 years (adjusted relative risk, 1.68; 95% CI, 1.05-2.70), and bullying elucidated a large part of this risk.
• No evidence of confounding by the autism polygenic risk score was noted.
• Similar but more precise results were obtained while analyzing in larger samples using multiple imputation.