Editing Prader–Willi syndrome (section)

=== Behavioral ===
PWS is frequently associated with a constant insatiable appetite, which persists no matter how much the patient eats, often resulting in [[morbid obesity|severe obesity]]. Caregivers need to strictly limit the patients' access to food, usually by installing locks on refrigerators and on all closets and cabinets where food is stored.<ref name="treatments">{{cite web |url=https://www.nichd.nih.gov/health/topics/prader-willi/conditioninfo/Pages/treatments.aspx |title=What are the treatments for Prader-Willi syndrome (PWS)? |access-date=June 16, 2016 |url-status=live |archive-url=https://web.archive.org/web/20160706030852/https://www.nichd.nih.gov/health/topics/prader-willi/conditioninfo/Pages/treatments.aspx |archive-date=July 6, 2016  }}</ref> It is the most common genetic cause of morbid obesity in children.<ref name="Nordqvist" /> Currently, no consensus exists as to the cause for this symptom, although genetic abnormalities in chromosome 15 disrupt the normal functioning of the [[hypothalamus]].<ref name="pmid9391886" /> Given that the hypothalamic [[arcuate nucleus]] regulates many basic processes, including appetite, a link may well exist. In the hypothalamus, nerve cells that produce [[oxytocin]], a hormone thought to contribute to satiety, are believed to be abnormal in people with PWS.<ref>{{cite journal |last1= Fahrenholz |first1= Falk |last2= Gimpl |first2= Gerald |date= 2001 |title= The Oxytocin Receptor System: Structure, Function, and Regulation |url= https://journals.physiology.org/doi/full/10.1152/physrev.2001.81.2.629 |journal= [[Physiological Reviews]] |volume= 81 |issue= 2 |pages= 629–683 |doi= 10.1152/physrev.2001.81.2.629 |pmid= 11274341 |s2cid= 13265083 |accessdate= 2023-01-06}}</ref>

People with PWS have high [[ghrelin]] levels, which are thought to contribute directly to the increased appetite, hyperphagia, and obesity seen in this syndrome.<ref name="pmid12091883">{{cite journal | vauthors = Cummings DE, Clement K, Purnell JQ, Vaisse C, Foster KE, Frayo RS, Schwartz MW, Basdevant A, Weigle DS | s2cid = 5253679 | title = Elevated plasma ghrelin levels in Prader Willi syndrome | journal = Nature Medicine | volume = 8 | issue = 7 | pages = 643–4 | date = July 2002 | pmid = 12091883 | doi = 10.1038/nm0702-643 | url = https://zenodo.org/record/1233443 }}</ref> Cassidy states the need for a clear delineation of behavioral expectations, the reinforcement of behavioural limits, and the establishment of regular routines.

The main mental health difficulties experienced by people with PWS include compulsive behaviour (usually manifested in skin picking) and anxiety.<ref name="Udwin" /><ref>{{cite journal |vauthors=Clark DJ, Boer H, Webb T |title=General and behavioural aspects of PWS: a review |journal=Mental Health Research |volume=8 |issue=195 |pages=38–49 |year=1995 }}</ref> Psychiatric symptoms, for example, hallucinations, paranoia and depression, have been described in some cases<ref name="Udwin" /> and affect about 5–10% of young adults.<ref name="pmid9391886" />  Patients are often extremely stubborn and prone to anger.<ref name="treatments" /> Psychiatric and behavioural problems are the most common cause of hospitalization.<ref>{{cite journal |vauthors=Cassidy SB, Devi A, Mukaida C |title=Aging in PWS: 232 patients over age 30 years |journal=Proc. Greenwood Genetic Centre |volume=13 |pages=102–3 |year=1994 }}</ref>

Typically, 70–90% of affected individuals develop behavioral patterns in early childhood.<ref name=Cas2008 /> Aspects of these patterns can include stubbornness, temper tantrums, controlling and manipulative behavior, difficulty with change in routine, and compulsive-like behaviors.<ref name=Cas2008 />