Prader-Willi Syndrome & Cognitive & Psychiatric Issues

Cognitive deficits often identified in individuals with PWS include:

  • Depressed general cognitive functioning or IQ
  • Processing deficits including short-term memory
  • Language processing deficits
  • Difficulty with higher order processing

Relative strengths reported in some people with PWS and that may be associated with their genetic subtype include:

  • Visual perception
  • Organization
  • Puzzle-solving

Cognitive findings may vary depending on the PWS genetic subtype with those individuals with a deletion performing more poorly in cognition and behavior assessments than those with maternal disomy. [Butler: 2004] [Butler: 2006] [Torrado: 2007] [Zarcone: 2007]

Behavior-related issues that are recognized in individuals with PWS include:

  • Hoarding
  • Repeating
  • Ordering
  • Need for sameness
  • Obsessive-compulsive behavior
  • Autism spectrum disorder

Developmental abnormalities in specific areas of the brain have been identified in individuals with PWS, but understanding what components are responsible for these abnormalities is still at an early stage. [Yamada: 2006] Although there are no obvious structural brain abnormalities in autopsy reports, functional MRI demonstrates over-activation of limbic and para-limbic areas of the brain when individuals with PWS receive food. [Holsen: 2006] [Shapira: 2005]

Individuals with PWS also demonstrate more psychotic symptoms and multiple psychiatric disorders, such as mood and obsessive-compulsive disorders, autistic behaviors, and psychosis, than the general population with intellectual disability. [Butler: 2006] Thinner children with PWS are sometimes noted to demonstrate more maladaptive behavior and symptoms of psychosis than heavier children. It is unknown if there is a direct association with weight or if the additional control of the environment necessary to keep children with PWS thin increases those behaviors. [Holsen: 2006] Adults with PWS have a slightly increased rate of psychotic illnesses, and those individuals with maternal disomy are more likely to exhibit psychosis than those with other genetic subtypes. [Butler: 2006]
Recent evidence of clinical and behavioral differences in PWS subjects with the type I (larger) and type II (smaller) 15q11-q13 deletion subtypes in PWS have been reported and also between those with the typical 15q11-q13 deletion and maternal disomy 15 (both 15s from the mother). [Butler: 2004] [Bittel: 2006]

Several authors have described the cognitive profile and behavior problems of individuals with Prader-Willi syndrome (PWS): [Jauregi: 2007] [Zarcone: 2007] [Reddy: 2007] [Dykens: 2008] [Manzardo: 2018]. For a more detailed description of psychiatric abnormalities in individuals with PWS, see [Butler: 2006].


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Authors & Reviewers

Initial publication: September 2008; last update/revision: July 2019
Current Authors and Reviewers:
Author: Merlin G. Butler, MD, PhD
Funding: This page was developed in partnership with the Heartland Genetic Services Network and was funded in part by a Health Resources Services Administration (HRSA) cooperative agreement (U22MC03962). We appreciate the Prader-Willi Syndrome Association (USA) for their outstanding support of individuals with PWS and their families and for the information they provide on their website – – to which we have provided several links within the Diagnosis Module.
Authoring history
2008: update: Merlin G. Butler, MD, PhDA
2008: first version: Kyna Byerly, MS, CGCCA
AAuthor; CAContributing Author; SASenior Author; RReviewer

Page Bibliography

Bittel DC, Kibiryeva N, Butler MG.
Expression of 4 genes between chromosome 15 breakpoints 1 and 2 and behavioral outcomes in Prader-Willi syndrome.
Pediatrics. 2006;118(4):e1276-83. PubMed abstract

Butler MG, Bittel DC, Kibiryeva N, Talebizadeh Z, Thompson T.
Behavioral differences among subjects with Prader-Willi syndrome and type I or type II deletion and maternal disomy.
Pediatrics. 2004;113(3 Pt 1):565-73. PubMed abstract / Full Text

Butler MG, Lee PDK, Whitman, BY.
Management of Prader-Willi Syndrome.
3rd ed. New York, NY: Springer Verlag Inc.; 2006. 0387253971
Textbook with diagnosis and management information for PWS. Includes clinical, genetic, social, family, and community issues.

Dykens EM, Roof E.
Behavior in Prader-Willi syndrome: relationship to genetic subtypes and age.
J Child Psychol Psychiatry. 2008;49(9):1001-8. PubMed abstract

Holsen LM, Zarcone JR, Brooks WM, Butler MG, Thompson TI, Ahluwalia JS, Nollen NL, Savage CR.
Neural mechanisms underlying hyperphagia in Prader-Willi syndrome.
Obesity (Silver Spring). 2006;14(6):1028-37. PubMed abstract / Full Text

Jauregi J, Arias C, Vegas O, Alén F, Martinez S, Copet P, Thuilleaux D.
A neuropsychological assessment of frontal cognitive functions in Prader-Willi syndrome.
J Intellect Disabil Res. 2007;51(Pt 5):350-65. PubMed abstract

Manzardo AM, Loker J, Heinemann J, Loker C, Butler MG.
Survival trends from the Prader-Willi Syndrome Association (USA) 40-year mortality survey.
Genet Med. 2018;20(1):24-30. PubMed abstract / Full Text

Reddy LA, Pfeiffer SI.
Behavioral and emotional symptoms of children and adolescents with Prader-Willi Syndrome.
J Autism Dev Disord. 2007;37(5):830-9. PubMed abstract

Shapira NA, Lessig MC, He AG, James GA, Driscoll DJ, Liu Y.
Satiety dysfunction in Prader-Willi syndrome demonstrated by fMRI.
J Neurol Neurosurg Psychiatry. 2005;76(2):260-2. PubMed abstract / Full Text

Torrado M, Araoz V, Baialardo E, Abraldes K, Mazza C, Krochik G, Ozuna B, Leske V, Caino S, Fano V, Chertkoff L.
Clinical-etiologic correlation in children with Prader-Willi syndrome (PWS): an interdisciplinary study.
Am J Med Genet A. 2007;143(5):460-8. PubMed abstract

Yamada K, Matsuzawa H, Uchiyama M, Kwee IL, Nakada T.
Brain developmental abnormalities in Prader-Willi syndrome detected by diffusion tensor imaging.
Pediatrics. 2006;118(2):e442-8. PubMed abstract

Zarcone J, Napolitano D, Peterson C, Breidbord J, Ferraioli S, Caruso-Anderson M, Holsen L, Butler MG, Thompson T.
The relationship between compulsive behaviour and academic achievement across the three genetic subtypes of Prader-Willi syndrome.
J Intellect Disabil Res. 2007;51(Pt. 6):478-87. PubMed abstract