Table 1.
Psychiatric Problems in PWS: Literature Review
| Authors | Sample size; instruments employed | Main findings | Limitations |
|---|---|---|---|
| (Whitman & Accardo, 1987) | 35 adolescents with PWS; Survey Diagnostic Instrument (SDI) which screens for the DSM-III criterion-based diagnostic categories of neurosis, and hyperactivity | The following diagnostic pattern was reported: neurosis, dysphoric, (1 probable); neurosis, compulsive, 3 (6 probable); neurosis, anxious, 4 (and 10 probable); somatization, 0; conduct disorder, violent 0; conduct disorder, antisocial, 0; hyperactivity, 1 (and 1 probable) | DSM-III criterion-based diagnostic categories were employed, SDI has no single standardized quantitative scoring system, no control group |
| (Curfs, Verhulst, & Fryns, 1991) | 27 individuals with PWS, CBCL | 87% had Total problem scores in the clinical range. No significant difference was found in the proportion of PWS patients scored in the clinical range on the Internalizing over the Externalizing syndrome | Small clinical sample, control group was not match for IQ |
| (Dykens, Hodapp, Walsh, & Nash, 1992) | 23 adults and adolescents with PWS, CBCL, Vineland Adaptive Behavior Scale | Externalising behaviours were significantly higher than internalising across all age groups and adolescent group had the highest externalising domain score | Small clinical sample recruited from a private service, no control group |
| (Dykens & Cassidy, 1995) | 25 children and 61 adults with PWS; The Reiss Scales for Children’s Dual Diagnosis and The Reiss Screen for Maladaptive Behavior scales | 56% of children were distracted and irritable, 52 had communication problems; 56 adults/adolescents were socially inadequate, 74% impulsive | Sample recruited from one PWS Association meeting, no control group |
| (Dykens & Kasari, 1997) | 43 children with PWS, CBCL | 72% obtained clinically elevated Total Scale score in contrast to 23% and 39% of the Down Syndrome and mentally retarded samples. PWS scored significantly higher on externalizing behaviour problems than the Down Syndrome sample | Parents were notified of the study through syndrome-specific parent organizations, groups were not matched on weight, and IQ |
| (Beardsmore, Dorman, Cooper, & Webb, 1998) | 25 adults with PWS; Psychiatric Present State-Learning Disabilities, Adaptive Behaviour Scales | The PWS group was found to have higher rates of affective disorders (17.4%), in which psychotic symptoms were common, but similar rates of schizophrenia/delusional disorders (4.3%) compared with the control group. None was found to have generalized anxiety or phobic disorders | Small sample, control group not matched for age, IQ |
| (Clarke, 1998) | 95 adults with PWS; Psychopathology Assessment Schedule for Adults with Developmental Disability (PAS-ADD) checklist | 6.3% had a possible psychotic disorder in the month before the assessment was made | Some reported psychotic symptoms may not be truly indicative of psychotic disorder as a checklist and not a diagnostic tool was employed |
| (Dykens et al., 1999) | 23 individuals with PWS due to paternal deletion and 23 age- and gender-matched subjects with maternal uniparental disomy: CBCL | “deletion” group had significantly higher Internalizing, Externalizing, and Total Child Behaviour Checklist mean raw scores, than did the uniparental disomy group | Small clinical sample, in some cases old IQ test results used |
| (State, Dykens, Rosner, Martin, & King, 1999) | 8 individuals with PWS, aged 4 to 20; Yale-Brown Obsessive Compulsive Scale | PWS subjects had greater numbers of obsessive compulsive symptoms resulting in significant impairment | Very small clinical sample recruited from a tertiary centre |
| (Akefeldt & Gillberg, 1999) | 44 individuals with PWS, age 0.8 to 36.3; Modified Greenswag Interview of parents with SSBP-PQ, Rutter parent questionnaire and ASSQ. Older Subjects completed the Birleson Depression Inventory and Eating Attitudes Test | Individuals with PWS had more behavior problems than those in the comparison group. Younger PWS cases had fewer behavior problems than older PWS cases. One woman with PWS developed psychotic symptoms, including agitation, abnormal beliefs and violent aggression problems | A large proportion of the parents in the non-PWS group also had ID, possibly influencing reporting of behaviours |
| (Einfeld, Smith, Durvasula, Florio, & Tonge, 1999) | 46 individuals with PWS; Developmental Behaviour Checklist (DBC) | 63% had mood swings without a reason, 43% were anxious | 30% of the controls were in the mild learning disability range and ascertainment of this group may well be biased towards those with greater behaviour disturbance |
| (Boer et al., 2002) | 25 individuals with PWS; clinical assessment | 28% had severe affective disorder with psychotic features, with a mean age of onset of 26 | No standardised assessment, small clinical, sample no control group |
| (Verhoeven, Tuinier, & Curfs, 2003) | 23 adults with PWS referred for neuropsychiatric assessment; diagnosed according to ICD-10 | 18 diagnosed as cycloid psychosis, 5 with bipolar affective disorder | Subjects selected from those referred for specialist assessment, no standard instrument used in diagnosis, no comparison between ratters |
| (Vogels, Matthijs, Legius, Devriendt, & Fryns, 2003) | 59 adults with the PWS; clinical assessment | 15.7% had experienced a psychotic episode with an age of onset varying from 13 to 19 yrs | No standardised instruments, no control group |
| (Steinhausen, Eiholzer, Hauffa, & Malin, 2004) | 58 individuals with PWS, aged 3 to 29; DBC | Behavioural disturbances and psychiatric symptoms increase with increasing age (apart from food-related behaviours) | Subjects recruited from tertiary care centre/parental support groups, lack of formal IQ and genetic information in a sizeable proportion of the sample |
| (Wigren & Hansen, 2005) | 58 children with PWS; Childhood Routines Inventory and Conner’s Parent Rating Scale | One-fourth showed clinical indices of ADHD, 3.4% - of anxiety | Cross-sectional data were collected using postal questionnaires and parents were informants; instruments not validated for ID population |
| (Kim, Yoo, Cho, Hong, & Kim, 2005) | 14 individuals with Prader-Willi syndrome, CBCL | 71.4% had social problems, 35% had attention problems | Small clinical sample, PWS diagnosis was made based on clinical assessment |
| (Descheemaeker, Govers, Vermeulen, & Fryns, 2006) | 59 adults with PWS, Pervasive Developmental Disorder Mentally Retardation Scale | 19% met the full diagnostic DSM-III-R criteria for PDD | Findings rely on informant-ratings of a screening questionnaire |
| (Hiraiwa, Maegaki, Okaa, & Ohnoa, 2007) | 165 individuals with PWS in Japan assessed by postal questionnaire to parents | Young adults with PWS had significantly more behavioural and psychiatric symptoms than those with non-PWS ID with psychotic symptoms in up to 27.6% over the previous five years | Questionnaire was not a standardised, validated instrument, no evidence of explanation to parents of terms such as ‘hallucination’, ‘delusion’ etc. Parents asked to comment on the prior five years, recall bias likely |
| (Soni et al., 2007) | 46 individuals with PWS, Psychiatric Assessment Schedule for Adults with Developmental Disability, Operational Criteria Checklist for psychotic and Affective illness | In deletion group (N=24): 41.7% Non-psychotic depressive illness, 37.5% Depressive psychosis, 20.8% Psychotic illness, in mUPD (n=22) 4.5% Non-psychotic depressive illness, 27.3% Depressive psychosis, 50% bipolar affective disorder, 18.2% psychotic illness | Initial screening was performed with invalidated screening questionnaire |
| (Reddy & Pfeiffer, 2007) | 73 children and adolescents with PWS; Devereux Scales of Mental Disorders | The PWS sample exhibited significantly more attention and acting out and anxiety problems than their peers with mental retardation-only | Sample was drawn from residential treatment facilities, only one standardized assessment procedure was employed to measure emotional and behavioural problems |
| (Zarcone, Peterson, Breidbord, Ferraioli, & Caruso-Anderson, 2007) | 73 individuals with PWS were assessed using the Yale-Brown Obsessive Compulsive Scale and the Compulsive Behavior Checklist | Individuals with the TI deletion had more compulsions regarding personal cleanliness and their compulsions, Individuals with the T II deletion were more likely to have compulsions related to specific academic areas | Although this study is limited because of the number of statistical comparisons and the small sample of individuals with the TI deletion (n=14) |
| (Dykens & Roof, 2008) | 88 individuals with PWS aged 5 to 51; CBCL | No compelling behavioral differences across PWS paternal deletion subtypes were found | Cross sectional nature, CBCL was used to assess mental health problems in adults |
| (Soni et al., 2008) | 46 individuals with genetically confirmed PWS; PAS-ADD, Family History and Life Events Questionnaires | The profile of psychiatric illness resembled an atypical affective disorder with or without psychotic symptoms | No control group |
| (Sinnema et al., 2011) | 98 adults with PWS; Developmental Behavior Checklist for Adults (DBC-A) | DBC-A total scores were higher in the consecutive age groups, with the most behavioral problems in the oldest age groups. Persons with mUPD had higher total scores on the DBC-A than persons with a deletion | No IQ measure, the study population is characterized by a predominance of older persons with PWS as the sample was “borrowed” from the study “Ageing in PWS” |