Maladaptive and compulsive behavior in Prader-Willi syndrome:
New insights from older adults 

Elisabeth M Dykens, Ph.D., UCLA Neuropsychiatric Institute, 760 Westwood Plaza, Los Angeles, CA  90064.

Introduction: The majority of studies on behavioral difficulties in persons with Prader-Willi syndrome (PWS) have focused on the child and adolescent years, as behavioral problems often manifest or worsen during these periods.  As older adults with PWS have not been routinely studied, it is unclear what shifts occur, if any, in the maladaptive and compulsive problems that characterize younger persons with PWS. 

Method: We compared 45 older adults with PWS aged 30 to 50 years, and to 195 children, adolescents and young adults.  Standardized measures were collected from parents (Child Behavior Checklist; Yale-Brown Obsessive-Compulsive Scale), along with basic information (age, gender, IQ, genetic status, degree of obesity-BMI, living status).  Families were recruited from our ongoing research and clinical programs, as well from the PWSA(USA) and California Prader-Willi Foundation. 

Results:  As expected, gains in certain maladaptive and compulsive behaviors were found across the child and adolescent years.  Young adults in their twenties appear to be at particularly high risk for elevated symptoms, even compared to the adolescent period.  For the first time ever, we show that both maladaptive and compulsive symptoms diminish to an astonishing degree in older adults with PWS.  Sweeping, across the board declines were found in externalizing behaviors, aggression, overall problems, and the number and severity of compulsive symptoms, including skinpicking.  We also examined predictors of these patterns, specifically gender, IQ, BMI, and living status.  Controlling for the effects of age, gender and the BMI emerged as the most consistent, significant predictors of skinpicking and other symptoms in both children and adults.

Discussion: Possible reasons for declines in problems among older adults are discussed, including the selective survival hypothesis.  Findings pave the way for longitudinal studies of aging in PWS, and possible medical, hormonal, and environmental predictors of more successful outcome in older adults with PWS.  

July 2003