title: Neurodevelopmental indices and the development of psychotic symptoms in subjects at high risk of schizophrenia.
abstract: BACKGROUND
  Neurological 'soft signs' and minor physical anomalies (MPAs) are reported to be more frequent in patients with schizophrenia than in controls.
  
  
  OBJECTIVE
  To determine whether these disturbances are genetically mediated, and whether they are central to the genesis of symptoms or epiphenomena.
  
  
  METHODS
  We obtained ratings in 152 individuals who were antipsychotic drug-free and at high risk, some of whom had experienced psychotic symptoms, as well as 30 first-episode patients and 35 healthy subjects.
  
  
  RESULTS
  MPAs and Neurological Evaluation Scale (NES) 'sensory integration abnormalities' were more frequent in high-risk subjects than in healthy controls, but there were no reliable differences between high-risk subjects with and without psychotic symptoms. MPAs were most frequent in high-risk subjects with least genetic liability and NES scores showed no genetic associations.
  
  
  CONCLUSIONS
  The lack of associations with psychotic symptoms and genetic liability to schizophrenia suggests that soft signs and physical anomalies are nonspecific markers of developmental deviance that are not mediated by the gene(s) for schizophrenia.
authors.affiliation: Edinburgh University Department of Psychiatry, Edinburgh, UK. s.lawrie@ed.ac.uk
authors.forename: S M
authors.initials: SM
authors.lastname: Lawrie
authors.forename: M
authors.initials: M
authors.lastname: Byrne
authors.forename: P
authors.initials: P
authors.lastname: Miller
authors.forename: A
authors.initials: A
authors.lastname: Hodges
authors.forename: R A
authors.initials: RA
authors.lastname: Clafferty
authors.forename: D G
authors.initials: DG
authors.lastname: Cunningham Owens
authors.forename: E C
authors.initials: EC
authors.lastname: Johnstone
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009048:Motor Skills; D009420:Nervous System / Q000254:growth & development*; D011597:Psychomotor Performance; D012559:Schizophrenia / Q000235:genetics* / Q000503:physiopathology; D012565:Schizophrenic Psychology