Assessment & Research

Behavioural and emotional problems in people with severe and profound intellectual disability.

Forster et al. (2011) · Journal of intellectual disability research : JIDR 2011
★ The Verdict

Profound ID shows fewer reported behaviour problems than severe ID—so analyse the groups separately.

✓ Read this if BCBAs writing assessment reports or behaviour plans for teens and adults with severe or profound ID.
✗ Skip if Clinicians who only serve mild ID or autism without co-occurring ID.

01Research in Context

01

What this study did

The team looked at 12 years of Developmental Behaviour Checklist (DBC) data.

They split clients into two groups: severe intellectual disability and profound intellectual disability.

Then they compared emotional and behavioural problem scores between the two groups.

02

What they found

The profound group scored lower on almost every DBC sub-scale.

Lower scores mean fewer reported problems, not more.

Pooling the two groups hides this clear difference.

03

How this fits with other research

Vos et al. (2010) saw the same pattern for well-being: profound ID scored lower than milder ID.

Matson et al. (2009) review shows people with ID already have tiny social networks; mixing severity levels blurs why.

Fellinger et al. (2022) link poor communication to more behaviour problems, but their sample was deaf adults—different risk profile.

Together the papers say: stop lumping severe and profound ID; split them to see real trends.

04

Why it matters

If you treat severe and profound ID as one group, you miss who needs what.

Use separate DBC norms for each level when you write reports or plan interventions.

This small switch gives clearer baselines and sharper goals for your clients.

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→ Action — try this Monday

Re-score last month’s DBC files: run one mean for severe ID clients and another for profound ID clients.

02At a glance

Intervention
not applicable
Design
other
Sample size
129
Population
intellectual disability
Finding
not reported

03Original abstract

BACKGROUND: People with severe and profound levels of intellectual disability (ID) are frequently examined as a single group in research. However, these two groups may be significantly different, particularly in the area of emotional and behavioural difficulties. METHOD: The Developmental Behaviour Checklist (DBC) was completed by parents and caregivers of 107 people with severe ID and 22 people with profound ID at four time periods across 12 years. Regression analyses were used to examine trends in sub-scale scores across time and groups. RESULTS: Significant differences between the groups of people with severe and profound ID were found. People with profound ID had significantly lower scores across all sub-scales except Social Relating. This was usually related to fewer items being selected as present for people with profound ID, as opposed to the scores being attributable to lower item severity scores. CONCLUSIONS: There are significant differences between groups of people with severe and profound ID in scores on the DBC, indicating differences in behavioural and emotional problems. Caution should be exercised by researchers treating these two disparate groups as a single group, and by practitioners translating such findings into practice.

Journal of intellectual disability research : JIDR, 2011 · doi:10.1111/j.1365-2788.2010.01373.x