Research In Action

Early identification of developmental disabilities has always been a pillar of our developmental and behavioral pediatric practice at CHOP. We know that early identification and treatment of various developmental disabilities, including autism, generally leads to improved outcomes at school and at home. A new study explored another reason to prioritize early identification of developmental disabilities: to reduce depression and self-harm behaviors among children on the autism spectrum.

What They Did

The Millennium Cohort Study (MCS), a nationally representative birth cohort study of nearly 20,000 children born in the United Kingdom between September 2000 and January 2002, served as the source of data in this analysis. As part of the MCS, parents were asked at various timepoints whether their child had received a diagnosis of an autism spectrum disorder (ASD) by a health professional. Associations between parent-reported age of ASD diagnosis and mental health outcome variables at age 14 years were analyzed. Children in the MCS without ASD diagnosis served as the control group.

• Data from more than 11,000 children were analyzed
• Children were categorized by age when parents first reported their child having a diagnosis of an ASD (no diagnosis, age 5, age 7, age 11, and age 14).
• Depressive symptoms in children at 14 years of age were measured using the Short Mood and Feelings Questionnaire, a self report measure.
• Self-harm behaviors were assessed based on a single question asked at age 14 ("In the past year have you hurt yourself on purpose in any way?").

What They Found

• Compared to the children without ASD, children in the ASD groups had:
  • A higher proportion of males
  • Increased parent-rated emotional symptoms at age 5
  • Cognitive abilities in the typical range (no difference between ASD and no ASD groups)
• The highest rate of depression/self-harm behavior occurred in children diagnosed after age 11.
• The rate of depression increased with increasing age of diagnosis, even after adjusting for confounders such as sex, birth status, family history and socioeconomic status, cognitive ability, and emotional symptoms at age 5.
  • Being diagnosed after age 7 was associated with nearly twice the odds of depression.
• Being diagnosed between ages 5 and 7, as well as after age 11, was associated with 2-3 times the odds of self-harm behaviors.
• Diagnosis before age 5 was not associated with either depression or self-harm behaviors.

Previous studies have found later diagnosis to be a potential risk factor for suicidal behaviors among adults on the autism spectrum. Potentially, early diagnosis and thus access to therapy and treatment to enhance emotional regulation skills, build social interaction skills, and to access school-based support could positively impact a child’s mental health. Interestingly, this study found that two groups, those diagnosed between ages 5 and 7, and those after age 11, had higher odds of self-harm behaviors compared to those diagnosed between ages 7 and 11, which deserves further exploration.

It should be noted that some participants in the MCS were not included in this analysis and were more likely to have cognitive delay, lower parental education, and more significant ASD-associated behaviors. That the ASD group had generally typical cognitive levels makes the findings less generalizable to the wider ASD population. The study also relied on parental report for ASD categorization (and did not measure ASD severity), and the questionnaire used to assess for depressive symptoms has not been validated among adolescents with ASD.

Despite these limitations, this study provides valuable insight regarding the importance of early ASD screening, diagnosis, and intervention to reduce the risk of depression and self-harm behaviors.