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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A sample of child guidance clinic cases with a young adult onset of schizophrenia were followed into middle age. Outcome ratings and marital status were used as predictive criteria for childhood measures of IQ, aggressiveness, and severity of disturbance. The interaction of IQ and levels of aggressive symptomatology revealed a subgroup of preschizophrenics with low IQ and below average aggressiveness who had disproportionately unfavorable adult outcomes and never-married status. The results demonstrated the important moderating effects of a second variable on the predictive statements made about an initial predictor.
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PMID:Preschizophrenics: low IQ and aggressive symptoms as predictors of adult outcome and marital status. 735 13

Schizophrenia is a lifelong illness, with symptoms beginning in late adolescence/early adulthood and persisting throughout the rest of the patient's life. Positive psychotic symptoms may fluctuate during the course of the illness, but negative symptoms, especially primary negative symptoms, and cognitive dysfunction are relatively constant. The negative symptoms of schizophrenia are both primary (associated with the illness) and secondary (due to depression, neuroleptic-induced parkinsonism or acute psychosis). While secondary negative symptoms may be reduced by treating the causative agent, primary negative symptoms are viewed as enduring, persisting between psychotic episodes. Conventional antipsychotics treat the positive symptoms of schizophrenia, but they have little effect on primary negative and cognitive symptoms. Primary negative symptoms are often associated with poor premorbid function, the male sex, and low IQ (Intelligence Quotient). In addition, most studies find that negative symptoms are associated with a poor overall outcome. Several studies, including our own, have suggested that primary negative symptoms are functionally localized to the frontal and parietal cortices. These kinds of data raise the possibility that primary negative symptoms may have a pathophysiological basis distinct from positive psychosis. Cognitive impairment also appears to be a relatively independent aspect of schizophrenia. Impairment may be evident in a subtle form from early childhood, and often precedes the development of psychotic symptoms. Additional impairment accrues with the onset of psychotic illness with little evidence, in the vast majority of cases, of progression over the course of the illness. Cognitive impairment is only modestly related to psychotic symptom severity and type. However, the extent, and perhaps specific types of cognitive impairment, appear to be predictive of functional outcome.
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PMID:The role of negative symptoms and cognitive dysfunction in schizophrenia outcome. 969 Sep 66

Neuropsychological studies of patients with schizophrenia have consistently identified deficits on tests sensitive to frontal lobe function. One paradigm that has been widely used is that of attentional set-shifting using the Wisconsin Card Sorting Test (WCST). In the present study, patients with chronic schizophrenia and with frontal lobe lesions were assessed on a computerised set-shifting task that provides a componential analysis of the WCST by distinguishing between intra-dimensional and extra-dimensional set-shifting. Out of 51 patients with schizophrenia, those with high IQ (n =24) were compared with patients with lesions in prefrontal cortex (n = 22) and with normal control subjects (n= 18). These three groups were well matched for age, sex and National Adult Reading Test (NART) IQ. The schizophrenic group showed a significantly higher rate of attrition at the intra-dimensional shift stage of learning compared with the other two groups. At the extra-dimensional shift stage, both the schizophrenic and frontal lesioned groups showed greater attrition than controls. Further, patients with schizophrenia who were able to learn the intradimensional reversal stage required more trials and made significantly more errors at that stage than the other two groups. In comparison with high IQ patients with schizophrenia, those with low IQ performed at a lower level but showed a qualitatively similar pattern of performance, providing further evidence that the set-shifting deficits were not simply explained by any global intellectual decline. Patients with schizophrenia who dropped out at the extradimensional shift stage had higher negative symptom scores compared with patients dropping out at previous learning stages, while patients failing at the intra-dimensional shift stage had lower scores for bradyphrenia (slowness of thought). The results suggest that patients with chronic schizophrenia fail to 'learn set' and are impaired at both set-shifting and concept formation. The relevance of these findings to understanding the nature of prefrontal cortical deficits in chronic schizophrenia is discussed. The implication of these findings to the rehabilitation of these patients is considered.
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PMID:Comparison of set-shifting ability in patients with chronic schizophrenia and frontal lobe damage. 1040 97

Risk factors for schizophrenia, such as genetic vulnerability and obstetric complications, have been associated with cognitive deficits in schizophrenia. We tested the association of these risk factors with general intellectual ability in offspring at high risk for psychoses and normal control subjects. Offspring of 182 parents with DSM-IV schizophrenia or affective psychoses were recruited and diagnosed from the Boston and Providence cohorts of the National Collaborative Perinatal Project (NCPP). Control subjects from the NCPP were selected to be comparable with affected parents based on the parent's age, ethnicity, study site, number of offspring enrolled in the NCPP, and payment status, and on the offspring's age, sex, and history of obstetric complications. Based on data prospectively acquired from pregnancy and events of gestation, labor, delivery, and the neonatal period, we derived a measure of probable hypoxic-ischemic insult. We also report on standardized measures of general intelligence (intelligence quotient [IQ]) collected at age 7. General linear mixed models were used to test for the simultaneous effects of genetic vulnerability, defined as parental diagnosis, and probable hypoxic insult on age 7 IQ. Specificity of the effects for schizophrenia compared with affective psychoses and sex effects were also tested. Low IQ at age 7 was significantly associated with genetic vulnerability to psychoses, in particular with schizophrenia.
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PMID:Impact of genetic vulnerability and hypoxia on overall intelligence by age 7 in offspring at high risk for schizophrenia compared with affective psychoses. 1088 34

Genetic, epidemiologic, and molecular studies concur that liability to schizophrenia is transmitted through the inheritance of a number of genes of relatively small effect, some of which are shared with other psychoses. Each of these susceptibility genes causes minor deviations that are relatively innocent in themselves, for example, increased lateral ventricular volume, schizotypal personality, or subtle cognitive difficulties. However, when an individual is unlucky enough to inherit several of these traits, their cumulative effect, often compounded by environmental hazards, propels that person over a threshold for the expression of frank psychosis. Early environmental risk factors for schizophrenia include urban and winter birth, fetal malnutrition and hypoxia, and possibly prenatal viral infections; these early hazards have only a modest risk-increasing effect, and operate in the context of genetic risk. Preschizophrenic children are more likely to have minor psychomotor and cognitive problems; low IQ has a linear relationship with risk for schizophrenia. However, schizophrenia is not simply a neurodevelopmental disorder, because risk factors have been identified that have their effects proximal to the onset of psychosis: drug abuse, immigrant status, and social adversity and isolation. Both genetic and environmental risk factors appear to operate across diagnostic categories and therefore support a dimensional model of psychosis.
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PMID:What risk factors tell us about the causes of schizophrenia and related psychoses. 1112 84

Risperidone, an antipsychotic agent with combined serotonin (5-HT2A) and dopamine (D2) receptor-blocking properties, is associated with fewer extrapyramidal side effects in adults than conventional neuroleptics. Approved in 1993 for the treatment of schizophrenia, recent studies have highlighted its potential in other conditions, such as the management of behavioral disturbances. This phase II, double-blind, placebo-controlled study evaluated the efficacy and tolerability of risperidone in the treatment of persistent behavioral disturbances in children with borderline intellectual functioning. Thirteen patients (6-14 years) with low IQ (66-85) were enrolled in and completed the 4-week study. Risperidone, in daily doses of > or = 0.01 mg/kg (mean dose at treatment endpoint = 0.05 mg/kg; mean total dose = 1.2 mg/day), was significantly more effective than placebo in improving Aberrant Behavioral Checklist (ABC) symptom cluster scores for irritation (p < 0.05) and hyperactivity (p < 0.01), Clinical Global Impression score (p < 0.05), the Visual Analogue Scale score for individual target symptom (p < 0.001), and Personal Assessment Checklist scores for social relationships (p < 0.05) and occupational attitudes (p < 0.05). In addition, the improvement in total ABC score in the risperidone-treated group was clinically relevant (65% improvement vs. baseline), whereas the placebo-treated patients only improved 7% versus baseline. There was no difference between risperidone- and placebo-treated groups with respect to the occurrence of extrapyramidal side effects, and risperidone was well tolerated. In conclusion, short-term risperidone treatment was well tolerated and significantly more effective than placebo in controlling behavioral disturbances in children with low IQ.
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PMID:Risperidone in the treatment of behavioral disturbances in children and adolescents with borderline intellectual functioning: a double-blind, placebo-controlled pilot trial. 1132 45

The present review looks at: (1) prevalence studies of sensory impairments in people with intellectual disability (ID); (2) studies looking at psychological and psychiatric disorders in people with sensory impairments; and (3) studies that have examined the association of sensory impairments with autism. Research has indicated that sensory impairments are more common in people with ID. Psychiatric disorders are believed to be more common in children with visual impairment (VI) when associated with other handicaps. Some authors believe that hearing impairment (HI) can result in personality disorders. Studies have also shown a higher prevalence of psychiatric disorders in children with HI and a higher incidence of deaf people in psychiatric hospitals than in the general population. Psychiatric disorders in children with HI are particularly associated with low IQ and low communication ability, especially in those with multiple handicaps. There is little evidence for a higher incidence of schizophrenia in people with HI. Blind people demonstrate many autistic-like features and there has been discussion in the literature as to their cause. Deaf people also demonstrate some similar features to those in autism, but an association with autism has not been conclusively made. Deaf-blind people commonly demonstrate problem behaviour (e.g. self-injury). Usher syndrome, which is the most common cause of deaf-blindness, is associated with psychiatric disorders, particularly psychosis. The need for assessment of sensory functioning in people with ID, the difficulties inherent in this and the need for specialist services is stressed.
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PMID:Sensory impairments, intellectual disability and psychiatry. 1173 34

A genetic subtype of schizophrenia has been described in 22q11 Deletion syndrome. Previous studies have described an excess of dermatoglyphic alterations in schizophrenia, such as low a-b ridge counts (ABRCs), a high frequency of ridge dissociations, and increased dermatoglyphic fluctuating asymmetry. Little is known however, about the dermatoglyphic profile of 22qDS subjects showing psychotic symptoms and its similarity to the previously reported anomalies in schizophrenia. We studied the palmar dermatoglyphics of 22 subjects with 22qDS of predominantly Caucasian origin, 15 of whom had psychotic illness, and in 84 healthy controls of similar ethnicity. We observed higher values for total ATD angle in cases than in controls (P = 0.04). In addition, there was an excess of radial figures in the hypothenar area in cases, especially in the left hand. Interestingly, greater fluctuating asymmetry, determined by the absolute difference between right and left ABRC, was observed in 22qDS subjects compared to controls (P = 0.05). However, no differences were found for ABRCs and frequency of dissociations. Despite the small sample size, the palmprints analyzed suggest the existence of an altered dermatoglyphic profile in 22qDS, involving: (i) ATD angle amplitude, (ii) presence of radial loops in the hypothenar area, and (iii) an increment of fluctuating asymmetry. The first two features are similar to those found in other genetic syndromes associated with low IQ, while high levels of fluctuating asymmetry have often been reported in schizophrenia.
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PMID:Dermatoglyphic profile in 22q deletion syndrome. 1521 30

Stability of schizophrenia diagnosis from adolescence to adulthood, antecedents of schizophrenia, and differences in developmental and behavioural histories between subjects with early onset schizophrenia (EOS) and with adult onset schizophrenia (AOS) were investigated in 145 adult subjects diagnosed with mental disorders in adolescence and re-diagnosed on the basis of medical records according to DSM-IV.A very high diagnostic stability schizophrenia was demonstrated at the 28-year follow-up. Several factors, including neurological adversities, delayed language development, low IQ, and congenital functional disability, differentiated significantly between schizophrenic subjects and non-schizophrenic subjects. Histories of concussion, physical abuse, parental divorce, and unstable familial context differentiated significantly between EOS and AOS subjects. Our findings support earlier evidence of schizophrenia being a chronic disorder with high diagnostic stability, and confirm the importance of neurological adversities, delayed language development, and low IQ as factors predictive of schizophrenia. Exploration of four case histories of AOS subjects delineates "pre-schizophrenic warning cluster" where combination of neurological adversities, temperamental problems, antisocial behaviour, preference for solitary play, and unstable family system constitute main factors.
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PMID:Stability and prediction of schizophrenia from adolescence to adulthood. 1579 87

Chromosome 22q11.2 deletion syndrome (22q11DS) is a common microdeletion syndrome associated with a markedly elevated risk of schizophrenia in adulthood. Cognitive impairments such as a low IQ and deficits in attention and executive function are common in childhood. The catechol O-methyltransferase (COMT) gene maps within the deleted region and is involved in the degradation of dopamine, a neurotransmitter thought to be important in cognition and the development of schizophrenia. Thus, we examined the correlation between neurocognitive deficits and a common polymorphism Val(158)Met in the COMT gene in a cohort of children with 22q11DS. Our results show that children with 22q11DS who have the Met allele have higher IQ and achievement scores and perform better on measures of prefrontal cognition, such as the Continuous Performance Task, as compared with those with the Val allele. These results confirm that the hemizygous COMT Val(158)Met genotype impacts upon cognition in children with 22q11DS.
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PMID:Cognitive correlates of a functional COMT polymorphism in children with 22q11.2 deletion syndrome. 1654 88


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