Service Delivery

Adult siblings of people with and without intellectual and developmental disabilities: Sibling relationship attitudes and psychosocial outcomes.

Sommantico et al. (2020) · Research in developmental disabilities 2020
★ The Verdict

Adult siblings of people with IDD feel less close and report worse mental health than siblings in neurotypical families.

✓ Read this if BCBAs working with adults with IDD during transition or adult day planning.
✗ Skip if Clinicians serving only early-childhood cases with no sibling involvement.

01Research in Context

01

What this study did

Heald et al. (2020) sent surveys to adult brothers and sisters. Some had a sibling with intellectual or developmental disabilities. Others had only neurotypical siblings.

The survey asked about sibling closeness, depression, anxiety, and life satisfaction.

02

What they found

Siblings of people with IDD felt less close to their brother or sister. They also reported more depression and anxiety and lower life satisfaction.

The differences were clear when compared with siblings from neurotypical families.

03

How this fits with other research

Older work painted a brighter picture. Busch et al. (2010) and Plant et al. (2007) found adult siblings of people with disabilities usually felt positive and close.

The new study flips that view by adding a neurotypical control group. The control group showed that "positive" siblings still lag behind typical sibling bonds.

McIntyre et al. (2017) help explain the gap. They showed that when siblings do feel positive, they give more help and enjoy better mental health. The 2020 study simply shows fewer reach that positive zone.

Abney et al. (2026) add detail. Their interviews revealed heavy caretaking stress and self-blame among siblings. Those themes line up with the higher depression and anxiety Heald et al. (2020) measured.

04

Why it matters

If you serve adults with IDD, remember the brother or sister may also need support. Quick mood screens at planning meetings can catch rising anxiety or depression. Offer sibling support groups or respite resources. Healthier siblings create stronger lifelong care networks for your client.

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→ Action — try this Monday

Add a two-question mood check for siblings at the next ISP meeting and list local sibling support groups in the resource packet.

02At a glance

Intervention
not applicable
Design
survey
Sample size
273
Population
intellectual disability, developmental delay, neurotypical
Finding
negative

03Original abstract

There is still little research on the relationships between adults with intellectual and developmental disabilities and their typically-developing siblings, despite the importance of these ties for siblings' psychological well-being, especially in terms of depression, anxiety, and life satisfaction. In this study, the sibling relationship attitudes of adult siblings of people with (N = 133) and without (N = 140) intellectual and developmental disabilities were explored. Feelings, behaviors, and thoughts related to sibling relationships were measured using the Lifespan Sibling Relationship Scale; depression was measured using the Beck Depression Inventory-II; anxiety was measured using the Beck Anxiety Inventory; and life satisfaction was measured using the Satisfaction With Life Scale. Results indicate that higher levels of positive sibling relationship attitudes are negatively related to levels of depression and anxiety, and positively related to levels of life satisfaction. Furthermore, adult siblings of people with intellectual and developmental disabilities show less positive sibling relationship attitudes, higher levels of depression and anxiety, and lower levels of life satisfaction. Finally, group membership, indirectly through sibling relationship attitudes, was related to depressive and anxious symptoms, as well as to life satisfaction. Implications for future research and policies are discussed.

Research in developmental disabilities, 2020 · doi:10.1016/j.ridd.2020.103594