Schizotypal cognitions as a predictor of psychopathology in adolescents with mild intellectual impairment.
BACKGROUND
There is evidence to suggest that among young people with mild intellectual disability there are those whose cognitive difficulties may predict the subsequent manifestation of a schizophrenic phenotype. It is suggested that they may be detectable by simple means.


OBJECTIVE
To gain adequate cooperation from educational services, parents and students so as to recruit a sufficiently large sample to test the above hypothesis, and to examine the hypothesis in the light of the findings.


METHODS
The sample was screened with appropriate instruments, and groups hypothesised as being likely or not likely to have the phenotype were compared in terms of psychopathology and neuropsychology.


RESULTS
Simple screening methods detect a sample whose psychopathological and neuropsychological profile is consistent with an extended phenotype of schizophrenia.


CONCLUSIONS
Difficulties experienced by some young people with mild and borderline intellectual disability are associated with enhanced liability to schizophrenia. Clinical methods can both identify those with this extended phenotype and predict those in whom psychosis will occur.
Division of Psychiatry, Kennedy Tower, Royal Edinburgh Hospital, Morningside Park, Edinburgh EH10 5HF, UK. e.johnstone@ed.ac.uk
Eve C
EC
Johnstone
David G C
DG
Owens
Peter
P
Hoare
Sonia
S
Gaur
Michael D
MD
Spencer
Jonathan
J
Harris
Andre W
AW
Stanfield
Vivien
V
Moffat
Norma
N
Brearley
Patrick
P
Miller
Stephen M
SM
Lawrie
Walter J
WJ
Muir
D000293:Adolescent; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000523:psychology*; D007859:Learning Disabilities / Q000523:psychology*; D008297:Male; D012569:Schizotypal Personality Disorder / Q000523:psychology*; D012606:Scotland