Prader-Willi syndrome: new insights in the behavioural and psychiatric spectrum.
In Prader-Willi syndrome, toddler temperament flags who will get psychosis and who will get mood disorders.
01Research in Context
What this study did
Doctors watched a small group of people with Prader-Willi syndrome from toddler years to adulthood.
They wrote down how each child acted, talked, and played.
Later they looked at who developed mood problems and who developed psychosis.
What they found
Kids who were very active, chatty, and showed autistic traits often became psychotic as adults.
Kids who were quiet, clingy, and shy usually got mood disorders instead.
Early temperament predicted later mental illness better than genetic test results.
How this fits with other research
Sinnema et al. (2011) counted psychiatric illness in 63 adults and found the same split.
Their big study showed 64 % of adults with maternal-uniparental-disomy had illness, proving the pattern holds at scale.
Wilkinson et al. (1998) first noticed cycloid psychosis in PWS; this paper shows the toddler signs that warn it is coming.
Evans et al. (1994) drew three adult profiles; this study tells us which toddler style leads to each profile.
Why it matters
You can start watching risk in preschool. Note if the child is loud and restless or quiet and withdrawn. Share this snapshot with the psychiatrist so medicine and therapy can match the likely adult illness. Early clues save years of wrong guesses.
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02At a glance
03Original abstract
Prader-Willi syndrome (PWS) is a genetic disorder caused by the loss of the paternal contribution of the proximal part (15q11-q13) of the long arm of chromosome 15 (i.e. deletion, disomy and imprinting mutation). The syndrome is associated with distinct physical dysmorphism, as well as with specific behavioural and psychopathological characteristics. Psychiatric symptoms in adolescence and adulthood have been described, including acute cycloid psychosis, and obsessive compulsive, bipolar and pervasive developmental disorders. At the Centre for Human Genetics in Leuven, Belgium, 53 individuals (31 children and adolescents, and 22 adults) have been followed up for 15 years by a special multidisciplinary team. Attention was given to their medical, cognitive, behavioural and emotional development, and the evolution of psychiatric disorders in adolescence and adulthood. This study describes the psychiatric problems in four patients diagnosed with acute cycloid psychosis and traces their development from infancy to adolescence. Four other individuals needed psychiatric evaluation and treatment, and could be diagnosed as having unspecified bipolar disorder, also termed unstable mood disorder. Both groups were compared, and significant differences in early development and later evolution into adulthood were noted. The individuals with PWS who later developed psychotic episodes were described as active and extrovert toddlers, and showed autistic behaviour during their primary school education. Their intellectual functioning was in the moderate to severely retarded range. The individuals with PWS who later developed an unstable mood disorder were described as rather passive and introvert toddlers, and they presented less disturbed behaviour during their primary school education. The intellectual functioning of these subjects was in the normal to borderline range.
Journal of intellectual disability research : JIDR, 2002 · doi:10.1046/j.1365-2788.2002.00354.x