Maladaptive behaviour in Prader-Willi syndrome in adult life

Thirty adults with Prader-Willi syndrome (PWS) were compared with 30 adults with non-specifrc learning disability matched for age, sex and severity of mental retardation. Maladaptive behaviors was assessed with the Aberrant Behavior Checklist (ABC), a 58-item structured Interview which rates behaviors 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 I. 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 behaviors. 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 behaviors are now needed.