Psychosocial and neurocognitive correlates of suicidal thoughts and behaviours amongst siblings of persons with and without neurodevelopmental conditions.
Siblings of kids with NDCs face sharply higher suicide risk — screen for rigid thinking, bullying, low mood, and self-harm at intake.
01Research in Context
What this study did
Finlay et al. (2023) compared brothers and sisters of kids with neurodevelopmental conditions to siblings of neurotypical kids. They looked for suicidal thoughts, self-harm, and thinking style differences.
The team used surveys and computer models to spot the strongest warning signs. They kept track of bullying, mood, and how flexible each teen was in their thinking.
What they found
Siblings of kids with NDCs had much higher rates of suicidal thoughts and self-injury. The computer model picked out four key red flags: rigid thinking, being bullied, feeling down, and past self-harm.
These siblings were not just a little higher risk — the difference was big enough to matter in everyday practice.
How this fits with other research
Totsika et al. (2023) found the same jump in self-harm, but in autistic people themselves. Brittany’s team extends that work by showing the risk spills over to brothers and sisters.
Kumar et al. (2025) saw small quality-of-life drops in kids with DCD. Brittany’s finding looks harsher, yet both studies agree parent and child reports can differ — always ask both sides.
de Graaf et al. (2011) linked motor problems to anxiety and depression in twins. Brittany adds suicidal thinking to that list and shows it can hit unaffected siblings too.
Why it matters
If your client has a brother or sister with autism, ADHD, or DCD, screen the whole family. Add four quick items to intake: bullying check, mood question, self-harm history, and a simple flexibility task like changing rules in a game. Picking up these signs early lets you start safety planning before crisis hits.
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02At a glance
03Original abstract
OBJECTIVE: Siblings of individuals with neurodevelopmental conditions (NDCs) have greater incidence of neuropsychiatric diagnoses and neurocognitive difficulties compared to siblings of persons without NDCs. Despite suicidality being labelled a global health crisis (WHO, 2014) and NDC siblings experiencing risk factors implicated in suicidality, no previous studies examined suicidality amongst adolescent and young adult siblings of persons with NDCs. Our study aimed to bridge this gap. METHOD: The present study used Bayesian analyses and risk classification models to examine individual and environmental risk factors associated with suicidal thoughts and behaviours amongst siblings of persons with and without NDCs (n = 267; 132 NDC, 135 control group, mean age 20.61, range 14-27, 76.40% female, 76.78% White Caucasian), as measured using self-report survey data and remote self-administered cognitive tests. RESULTS: NDC siblings had higher rates of current nonsuicidal self-injury (NSSI; 18.94% versus 14.07%, δ = -0.32), suicidal ideation (25.76% versus 8.89%, δ = -0.40) and history of suicide attempts (18.18% versus 4.44%, δ = -0.43) compared to controls. Classification models using boosting and random forest demonstrated adequate performance: positive predictive value 0.86-0.91, negative predictive value 0.81-0.90, false negative rates 0.11-0.24. Cognitive inflexibility, alexithymia, inattention, bullying, depression, NSSI, and eating or psychotic disorder history had the highest relative importance in predicting lifetime suicidality. Poorer executive functioning (measured by the Wisconsin Card Sorting Task, Sustained Attention to Response Task, Stop Signal Task, and N-Back 2-back task) was strongly correlated with suicidality. CONCLUSIONS: Screening for proximal and modifiable risk factors is critical to inform suicidal behaviour intervention and prevention programs for at-risk siblings.
Research in developmental disabilities, 2023 · doi:10.1016/j.ridd.2023.104566