Family History Of Autism And ADHD Vary With Recruitment Approach And SES

Autism and ADHD are neurodevelopmental conditions that impact an individual’s behavior, communication, and cognitive processes.

Autism is characterized by challenges in social interaction, restricted interests, and repetitive behaviors, while ADHD is associated with inattention, hyperactivity, and impulsivity.

Research suggests a strong genetic component to both conditions, with increased likelihood of diagnosis among individuals who have a sibling or parent with autism or ADHD. Moreover, there is significant co-occurrence between autism and ADHD, further indicating potential shared genetic underpinnings.

Understanding the heritability and familial patterns of these conditions is crucial for early identification, intervention, and support for individuals and families affected by autism and ADHD.

Bazelmans, T., Scerif, G., Holmboe, K., Gonzalez‐Gomez, N., & Hendry, A. (2024). Rates of family history of autism and ADHD varies with recruitment approach and socio‐economic status. British Journal of Developmental Psychology, 42(2), 117–132. https://doi.org/10.1111/bjdp.12469

Key Points

• The prevalence of family history (FH) of autism and ADHD varies depending on the recruitment approach used in developmental studies. Rates were 3-9% for diagnosed cases.
• The highest rate of FH-autism/ADHD was in the sample recruited through an online participant pool, which also had the most socio-economically diverse families.
• Lower parental education and income were associated with higher rates of FH-ADHD. Lower parental education was associated with increased FH-autism.
• Recruitment strategies meaningfully impact sample neurodiversity and the generalizability of findings. Online crowdsourced samples may be more representative than university databases/social media.

Rationale

Autism and ADHD are highly heritable neurodevelopmental conditions. Children with a parent or sibling diagnosed with autism or ADHD have a significantly higher likelihood of receiving a diagnosis themselves (Chen et al., 2017; Constantino et al., 2010; Messinger et al., 2013; Miller et al., 2019; Risch et al., 2014).

Around 30-40% of individuals with autism or ADHD have a co-occurring diagnosis of the other condition (Lai et al., 2019; Rong et al., 2021).

However, family history of autism/ADHD is not often considered during recruitment for developmental studies, despite the high recurrence rates and impact on neurodivergent development.

This study aimed to examine how rates of FH-autism/ADHD vary across different recruitment methods and family socioeconomic factors in young children.

Method

The researchers looked at rates of autism or ADHD among family members of children who are autistic or have ADHD.

Participants were 1055 children aged 9-46 months from three UK-based samples recruited using different methods. The samples varied in socioeconomic diversity.

Results

• The rate of FH-autism or FH-ADHD was 3–9% for diagnosed cases.
• The rate was highest in the sample recruited through an online participant pool, which also consisted of the most socio-economically diverse families.
• Lower parental education and family income were associated with higher rates of FH-ADHD. Lower parental education was associated with increased FH-autism.

Insight

This study provides important insights into how recruitment methods and family socioeconomic factors relate to rates of FH-autism/ADHD in developmental research samples.

The finding that online crowdsourced samples had the highest rates of FH-autism/ADHD and greatest socioeconomic diversity suggests this recruitment approach may yield more representative samples than university databases or social media.

The associations between lower parental education/income and higher rates of FH-ADHD/autism align with previous research linking autism and ADHD to socioeconomic status (Durkin et al., 2017; Russel et al., 2016).

Future research should examine potential mechanisms underlying these associations and take family history and socioeconomic diversity into account when developing recruitment strategies.

Strengths

Below are some notable strengths with this study:

• Examined rates of FH-autism/ADHD across multiple samples recruited using different methods
• Large total sample size of over 1,000 participants
• Included socioeconomically diverse families

Limitations

Below are some of the limitations of this study:

• Samples were all from the UK, limiting geographic generalizability
• Family history was based on parent-report, not verified diagnoses
• Cross-sectional design prevents causal conclusions about links between socioeconomic factors and FH-autism/ADHD

Implications

The results suggest that developmental researchers should carefully consider how their recruitment strategies may impact the neurodiversity and representativeness of their samples.

In particular, online crowdsourcing may be an effective way to recruit more socioeconomically diverse samples with higher rates of FH-autism/ADHD compared to traditional university or social media-based approaches.

Clinically, the findings highlight the importance of screening for family history, especially among socioeconomically disadvantaged families, to identify children at higher likelihood of autism/ADHD.

Finally, the socioeconomic associations underscore the need for policies and services that support neurodivergent individuals and families across the socioeconomic spectrum.

References

Primary reference

Bazelmans, T., Scerif, G., Holmboe, K., Gonzalez‐Gomez, N., & Hendry, A. (2024). Rates of family history of autism and ADHD varies with recruitment approach and socio‐economic status. British Journal of Developmental Psychology, 42(2), 117–132. https://doi.org/10.1111/bjdp.12469

Other references

Chen, Q., Brikell, I., Lichtenstein, P., Serlachius, E., Kuja‐Halkola, R., Sandin, S., & Larsson, H. (2017). Familial aggregation of attention‐deficit/hyperactivity disorder. Journal of Child Psychology and Psychiatry, 58(3), 231-239. https://doi.org/10.1111/jcpp.12616

Constantino, J. N., Zhang, Y. I., Frazier, T., Abbacchi, A. M., & Law, P. (2010). Sibling recurrence and the genetic epidemiology of autism. American Journal of Psychiatry, 167(11), 1349-1356. https://doi.org/10.1176/appi.ajp.2010.09101470

Durkin, M. S., Maenner, M. J., Baio, J., Christensen, D., Daniels, J., Fitzgerald, R., … & Yeargin-Allsopp, M. (2017). Autism spectrum disorder among US children (2002–2010): Socioeconomic, racial, and ethnic disparities. American journal of public health, 107(11), 1818-1826. https://doi.org/10.2105/AJPH.2017.304032

Lai, M. C., Kassee, C., Besney, R., Bonato, S., Hull, L., Mandy, W., Szartmari, P., & Ameis, S. H. (2019). Prevalence of co-occurring mental health diagnoses in the autism population: a systematic review and meta-analysis. The Lancet Psychiatry, 6(10), 819-829. https://doi.org/10.1016/S2215-0366(19)30289-

Messinger, D. S., Young, G. S., Webb, S. J., Ozonoff, S., Bryson, S. E., Carter, A., … & Zwaigenbaum, L. (2015). Early sex differences are not autism-specific: A Baby Siblings Research Consortium (BSRC) study. Molecular autism, 6, 1-12. https://doi.org/10.1186/s13229-015-0027-y

Miller, M., Musser, E. D., Young, G. S., Olson, B., Steiner, R. D., & Nigg, J. T. (2019). Sibling recurrence risk and cross-aggregation of attention-deficit/hyperactivity disorder and autism spectrum disorder. JAMA pediatrics, 173(2), 147-152.

Risch, N., Hoffmann, T. J., Anderson, M., Croen, L. A., Grether, J. K., & Windham, G. C. (2014). Familial recurrence of autism spectrum disorder: evaluating genetic and environmental contributions. American Journal of Psychiatry, 171(11), 1206-1213. https://doi.org/10.1176/appi.ajp.2014.13101359

Rong, Y., Yang, C. J., Jin, Y., & Wang, Y. (2021). Prevalence of attention-deficit/hyperactivity disorder in individuals with autism spectrum disorder: A meta-analysis. Research in Autism Spectrum Disorders, 83, 101759. https://doi.org/10.1016/j.rasd.2021.101759

Russell, A. E., Ford, T., Williams, R., & Russell, G. (2016). The association between socioeconomic disadvantage and attention deficit/hyperactivity disorder (ADHD): a systematic review. Child Psychiatry & Human Development, 47, 440-458. https://doi.org/10.1007/s10578-015-0578-3

Keep Learning

Here are some potential discussion questions for a college class on this paper:

1. How might researchers weigh the pros and cons of different recruitment strategies in light of these findings? What additional factors should they consider?
2. What potential mechanisms might explain the associations between lower socioeconomic status and higher rates of FH-autism/ADHD? How could future research test these mechanisms?
3. How can developmental research become more inclusive and representative of the full spectrum of neurodiversity? What other steps, beyond broadening recruitment, may be needed?
4. What are the implications of these findings for clinical screening and support services for families of children with or at risk for autism/ADHD? How can we ensure equitable access?
5. How might intersectionality between neurodivergence and socioeconomic disadvantage shape individuals’ and families’ experiences and outcomes? What related research questions does this study raise?