20 It is also interesting in that this and several of the other cohort studies point to receptive language deficits as being particularly noticeable in preschizophrenic individuals.14,15,18,21 Much research indicates that auditory hallucinations are Tivantinib in vivo disorders of inner language.22,23 Perhaps it is not surprising that children who have impaired language perception are more prone to misperceive their own inner speech as voices in adult life. Isohanni et al24 studied Inhibitors,research,lifescience,medical over 12 000 subjects from the 1966 Finnish birth cohort at the time of their 31st birthday. Using a national hospital register, they identified 100 cases
of schizophrenia, 55 other psychoses, and 315 nonpsychotic disorders. Data on the ages at which subjects learned to stand, walk, and control bowel and bladder functions were compared across the groups. Delayed milestones increased the risk for later psychosis Inhibitors,research,lifescience,medical in a linear fashion (so early milestones implied protection). There was no such association between milestones and nonpsychotic disorders. Apart from the interesting “dose-response effect” described, this study suggests that the childhood precursors may be specific to psychotic disorders as opposed to conveying risk for general psychopathology. Neuropsychological characteristics Inhibitors,research,lifescience,medical in late adolescent/early adult life David et al25
Inhibitors,research,lifescience,medical investigated the association between 10 and the later development of psychosis in a cohort study of nearly 50 000 18-year-old males who were conscripted into theSwedish army in 1969 to 1970. By 1983, 195 subjects in the cohort had been admitted to hospital with schizophrenia and another 192 with nonschizophrenic psychosis. There was a highly significant association between low IQ scores and the subsequent development of schizophrenia. Indeed, the relationship between schizophrenia and IQ was linear, with risk gradually Inhibitors,research,lifescience,medical increasing as IQ fell at all levels of intellectual ability. The risk for nonschizophrenic
psychoses was also higher in those with lower IQ, but the effect was less marked and nonlinear. The effect size of the low IQ risk factor exceeded that of any other known environmental risk factors. The association between low IQ and schizophrenia could be directly causal with cognitive Cell press impairment leading to false beliefs and perceptions. Alternatively, the association could be indirect with factors such as abnormal brain development increasing the risk for schizophrenia, and incidentally causing the lower IQ. Davidson et al26 examined assessment scores for nearly 10 000 16- and 17-year-old boys entering the Israeli army Deficits in social functioning, organizational ability, and intellectual functioning predicted later hospitalization with schizophrenia.