Assessment & Research

Maladaptive behaviour in Prader-Willi syndrome in adult life.

Clarke et al. (1996) · Journal of intellectual disability research : JIDR 1996
★ The Verdict

Adults with Prader-Willi syndrome bring heavy daily irritability and odd speech, but lab studies show these behaviors can be cut with clear cues and effort changes.

✓ Read this if BCBAs serving adults with Prader-Willi or other genetic ID in residential or day programs.
✗ Skip if Clinicians who work only with young children or mild behavior.

01Research in Context

01

What this study did

The team compared adults with Prader-Willi syndrome to adults with other intellectual disabilities.

They used the Aberrant Behavior Checklist to count tantrums, irritability and odd speech.

All adults lived in state-run homes, so settings were similar.

02

What they found

The Prader-Willi group scored much higher on irritability and repetitive speech.

Seventeen checklist items passed the "mild problem" line, showing daily life is tougher for these adults.

In short, challenging behavior is the norm, not the exception.

03

How this fits with other research

Fyfe et al. (2007) later showed one adult could cut stereotypy to zero when a red card signaled punishment.

That seems to clash with Cameron et al. (1996), who saw constant high rates.

The gap is design: the 1996 study captured real-life baselines, while 2007 used lab controls and a punishment cue.

Oliver et al. (2002) also proved pica can drop when we make the item harder to reach, giving hope that response-effort tricks may work for Prader-Willi behavior too.

04

Why it matters

Expect daily outbursts and plan for them. Build in frequent breaks, sensory swaps and high-effort access to preferred food or objects. Use visual cues that signal when a behavior will cost a token or delay a snack. These small moves can turn the high rates seen in this study into the low rates shown in later single-case work.

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Put the most wanted snack in a hard-to-open jar and give a brief visual cue before each access to build stimulus control and lower grabs.

02At a glance

Intervention
not applicable
Design
quasi experimental
Sample size
60
Population
intellectual disability, other
Finding
negative
Magnitude
large

03Original abstract

Thirty adults with Prader-Willi syndrome (PWS) were compared with 30 adults with non-specific learning disability matched for age, sex and severity of mental retardation. Maladaptive behaviour was assessed with the Aberrant Behavior Checklist (ABC), a 58-item structured interview which rates behaviours from 0 (not a problem) to 3 (severe problem) and which yields five factors (I) irritability, agitation; (II) lethargy, withdrawal; (III) stereotypic behavior; (IV) hyperactivity, non-compliance; and (V) inappropriate speech). The PWS sample had significantly higher factor I (P < 0.001) and factor V (P < 0.05) scores. The PWS sample had mean scores above 1 for 17 ABC items; the contrast subjects had no mean scores above 1. The factor I scores for the PWS sample were similar to those of inpatients in hospital facilities for adults with mental retardation and mental illness or severely challenging behaviour. The results support previous work, and extend it by suggesting that temper tantrums, self-injury, impulsiveness, lability of mood, inactivity and repetitive speech are characteristic behaviours in PWS in adult life. Studies of the reasons for heterogeneity in behaviour are now needed.

Journal of intellectual disability research : JIDR, 1996 · doi:10.1046/j.1365-2788.1996.743743.x