BACKGROUND: Longitudinal studies indicate that future schizophrenia patients exhibit lower IQ than healthy controls. Recent studies suggest that future patients with other mental illnesses obtain lower pre-morbid IQ. The aims of this study were to compare pre-morbid IQ among five diagnostic categories and normal controls, to examine the distribution of pre-morbid IQ, and to investigate the relationship between pre-morbid IQ and risk of mental illness. METHOD: A total of 7486 individuals hospitalized with psychiatric disease and 20 531 controls. IQ was measured at the draft board and hospital diagnoses [schizophrenia (Sz), non-schizophrenic, non-affective psychoses (NSAP), affective (AD), personality (PD) and neurotic/stress disorders (ND)] were followed up to ages 43-54 years. Individuals hospitalized < or = 1 year after appearing before the draft board were excluded. RESULTS: All future patients obtained significantly lower pre-morbid IQ than controls (3-7 IQ points), AD had the highest IQ and PD the lowest. In each diagnostic category, decreasing IQ was associated with an increasing risk of becoming a patient [odds ratios (ORs) 0.5-2.5 over the full IQ spectrum]. IQ distributions was nearly normal and uni-modal. CONCLUSIONS: IQ deficits in each diagnostic category may reflect different functional patterns and temporal vicissitudes of the specific pathogenetic processes involved in different mental disorders.
BACKGROUND: Longitudinal studies indicate that future schizophreniapatients exhibit lower IQ than healthy controls. Recent studies suggest that future patients with other mental illnesses obtain lower pre-morbid IQ. The aims of this study were to compare pre-morbid IQ among five diagnostic categories and normal controls, to examine the distribution of pre-morbid IQ, and to investigate the relationship between pre-morbid IQ and risk of mental illness. METHOD: A total of 7486 individuals hospitalized with psychiatric disease and 20 531 controls. IQ was measured at the draft board and hospital diagnoses [schizophrenia (Sz), non-schizophrenic, non-affective psychoses (NSAP), affective (AD), personality (PD) and neurotic/stress disorders (ND)] were followed up to ages 43-54 years. Individuals hospitalized < or = 1 year after appearing before the draft board were excluded. RESULTS: All future patients obtained significantly lower pre-morbid IQ than controls (3-7 IQ points), AD had the highest IQ and PD the lowest. In each diagnostic category, decreasing IQ was associated with an increasing risk of becoming a patient [odds ratios (ORs) 0.5-2.5 over the full IQ spectrum]. IQ distributions was nearly normal and uni-modal. CONCLUSIONS: IQ deficits in each diagnostic category may reflect different functional patterns and temporal vicissitudes of the specific pathogenetic processes involved in different mental disorders.
Authors: Holger J Sørensen; Erik L Mortensen; Jason Schiffman; Morten Ekstrøm; Danielle Denenney; Sarnoff A Mednick Journal: Psychiatry Res Date: 2010-05-05 Impact factor: 3.222
Authors: Julie Gauthier; Nathalie Champagne; Ronald G Lafrenière; Lan Xiong; Dan Spiegelman; Edna Brustein; Mathieu Lapointe; Huashan Peng; Mélanie Côté; Anne Noreau; Fadi F Hamdan; Anjené M Addington; Judith L Rapoport; Lynn E Delisi; Marie-Odile Krebs; Ridha Joober; Ferid Fathalli; Fayçal Mouaffak; Ali P Haghighi; Christian Néri; Marie-Pierre Dubé; Mark E Samuels; Claude Marineau; Eric A Stone; Philip Awadalla; Philip A Barker; Salvatore Carbonetto; Pierre Drapeau; Guy A Rouleau Journal: Proc Natl Acad Sci U S A Date: 2010-04-12 Impact factor: 11.205
Authors: D S Christensen; T Flensborg-Madsen; N E Andersen; I B Rosenkær; E L Mortensen Journal: Soc Psychiatry Psychiatr Epidemiol Date: 2021-01-03 Impact factor: 4.328
Authors: R Revsbech; E L Mortensen; J Nordgaard; L B Jansson; D Saebye; T Flensborg-Madsen; J Cutting; J Parnas Journal: Eur Arch Psychiatry Clin Neurosci Date: 2016-11-12 Impact factor: 5.270