Beyond symptom dimensions: schizophrenia risk factors for patient groups derived by latent class analysis.
BACKGROUND
Patients grouped by latent class analysis of symptoms show some consensus between studies, and may be less etiologically heterogeneous than current diagnoses. If so, the effect size of 'neurodevelopmental' risk factors may be greater than in equivalent DSMIV diagnostic groups.


METHODS
Two hundred fifty six individuals with neurodevelopmental risk factors recorded in the National Child Development Study (1958) UK birth cohort were grouped by data-driven illness subtypes, derived previously in over 1000 individuals. The effect sizes of these risks were compared between data-derived and DSMIV schizophrenia (295.x) groups.


RESULTS
Compared to DSMIV schizophrenia, the data-driven subtype broadly characterized by the presence of psychotic symptoms in the absence of affective symptoms showed significantly greater effect sizes in eight out of thirteen continuously-rated risk factors: birth weight, cognition, childhood behavioural problems, and neurological softsigns including handedness.


CONCLUSIONS
A data-driven subgroup of schizophrenia patients, characterized as lacking co-morbid depressive symptoms, is less heterogeneous with respect to neurodevelopmental etiology.
Division of Psychiatry, Nottingham University, A floor, South Block, Queen's Medical Centre, Nottingham NG7 2UH, UK. stuart.leask@nottingham.ac.uk
S J
SJ
Leask
J K
JK
Vermunt
D J
DJ
Done
T J
TJ
Crow
M
M
Blows
M P
MP
Boks
D000704:Analysis of Variance; D002648:Child; D015331:Cohort Studies; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D010552:Personality Assessment; D011569:Psychiatric Status Rating Scales; D012189:Retrospective Studies; D012307:Risk Factors; D012559:Schizophrenia / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D012565:Schizophrenic Psychology